Date: Tue, 9 Jan 1996 09:36:20 -0500 From: Marc Zeitlin Subject: Safe-t-poxy type epoxy system available - rec.aviation.homebuilt #16150 Our own (Gordon Bowen) writes (in rec.aviation.homebuilt #16150): |> To: Composite builders |> |> Hexcel Co. decision to sell the Resins Group to HB Fuller has left |> composite homebuilders who like the old Safe-t-poxy systems without a |> source of materials. Also the purchase of Alexander Aero by Aircraft |> Spruce has limited the amount of competitors in the composites materials |> market. |> |> We've decided to make an epoxy system similar to the old Safe-t-poxy I |> and II. The hardeners are EZ-83 (fast), EZ-84 (med.) and EZ-87 (slow. |> The resins are EZ-09 (lower visc.) and EZ-10 (normal visc). |> |> The mix ratios remain 44:100. The technology and materials used are |> similar to the old systems. For legal reason we cannot call them |> Safe-t-poxy but they're are close as you can get and remain legal. |> |> These epoxy systems, fiberglass and foams are available from: |> |> Diversified Materials Inc. |> La Mesa, CA. |> PH- 619-464-4111 |> Ask for Rich Christy |> |> Thanks- Gordon Bowen- Former Hexcel Epoxy Product Manager |> OSHKOSH Composites Workshop Instructor/Coordinator and Composites Forums |> Instructor. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Thu, 18 Jan 1996 07:51:09 -0600 From: Scott Mandel Subject: Epoxy Cleanup Neat trick I learned a few months ago. Get two resealable jars. I'm talking about the glass jars with a glass lid and rubber seal between the lid and the jar, held together by a metal thing. I found some in a craft store but I think they're available elsewhere. Anyhow, fill them about two inches full with MEK. Use one to clean everything. Dunk epoxy, flox, and micro laden stuff, and use the other to store your brushes after you're done dunking. I also use my just dunked brushes to clean squegees, scissors and anyhting else I've gunked up. I've found this acually makes cleanup much easier. I use less MEK, less brushes (Three are still good as new after 2 months), and my wife no longer carps at me for leaving brushes in the freezer. I find I usually don't get much reuse from those freezer brushes anyhow. This has been a winner for me all the way around. Thanks go to, Jim Marshall (a fellow Texas Cozy builder) for showing this to me. _________________ ______________________ / Scott L. Mandel \ /Email: mandel@esy.com \ \_________________/_________________________\______________________/ From: Michael Antares Subject: 2426 epoxy availability Date: Mon, 29 Jan 1996 19:36:20 -0800 Just spoke with Janet at Wicks this morning and she informed me that = starting mid-February they will be carrying the 2426--the RAE = system--epoxy again (which had been discontinued a few months ago by = everyone since Hexcell was requiring a 500 gallon minimum buy). The = timing is perfect for me as I actually had called her to order my first = 2427 and I wasn't looking forward to cleaning out my pump and resetting = the ratio. Date: Sun, 25 Feb 1996 18:22:00 -0800 From: aerocad@ix.netcom.com (Jeff S. Russell) Subject: Resin users Warning............. This is multipart MIME message. --ryntpkjljsyvnfxvkljclfrdrsckui Content-Type:text/plain; charset=US-ASCII; name="NCZ125E.TMP" "text attached" <> (A warning to all) who live in humid climates. --ryntpkjljsyvnfxvkljclfrdrsckui Content-Type:text/plain; charset=US-ASCII; name="resin.txt" AeroCad has used these types of epoxy systems and seen very different results in our testing: Hexcel's RAE 2426 resin & 2176,2177 hardeners Hexcel's EPOLITE 2410 resin & 2183,2184,2187 hardeners Hexcel's EPOLITE 2318 resin & 2316 hardener Hexcel's 2427 resin & hardener PTM&W 3660 resin & PR2032 hardeners (fast and slow) 5 different types CLEARSTREAM EPOXY WEST SYSTEMS 105-5 resin & 205,206 hardeners (for finishing) ALPHA-POXY (for finishing) RYCHOR EPOXY (for finishing) Depending on where you are building your project, North, South, East or West, the climate that your are in will (most effect) the way an Amine Base resin will work for you. The only type of Resin that we have used that's not Amine Based was Hexcel's EPOLITE 2183,2184,2187 hardeners. The bad thing that is this hardener has MDAand Styrene as an additive so they call this a Styrene-Monomer Base. This hardner dissipates water as it's curing so that Amine Blush or other water related problems go away. AMINE BLUSH Amine blush is caused by high humidity and by the amine group in the resins and hardeners accepting C02 and H20. This is noticeable by a white film around the lids of a laminate, or by a thin film that gums up your sandpaper. So often people call and think that their resins are not curing and that they have been supplied faulty materials, but the real culprit is (amine blush) caused by high humidity and high temperatures. As the temperatures increase, the air can carry much higher columns of moisture and carbon dioxide. This, coupled with the temperature increasing the number of reactive sites available, sets up the perfect condition for amine blush to occur. With all this technical goop set aside, most builders only want to know how to prevent amine blush or how to cure the problem that they now have on their laminate. The following are remedies for amine bluish: 1. Use peel ply. Amine blush forms most generally on the outer most portion of the lay-up. By using peel ply the amine blush is removed when the peel ply is removed, leaving a laminate free of amine blush and ready for secondary bonding. 2. Use a high-quality resin, or use a fast hardener. The length of time that resin is uncured is the length of time of exposure for the formation of amine blush. If this time is reduced, so will the amount of amine blush. 3. Cap all resins as soon as possible. This reduces resins and hardeners exposure to the elements that form amine blush. (DO NOT USE EPOXY PUMPS) Humidity in your fiberglass and core material can also produce reactions on how a laminate will turn out. 4. Work in a controlled environment if possible. It is often hard to have a temperature and humidity controlled shop, but we can do our lay-ups at times when the temperature is not 100 plus, and the humidity is not 99% like we frequently see in North Carolina. 5. Amine blush can be washed off with a clean cloth and warm water once the initial cure has occurred. 6. Sanding will remove the amine blush and also gum up your sandpaper. Amine blush must be removed before subsequent or secondary laminates or lay-ups are initiated. If the amine blush is not removed, the intralaminar shear strength is only as strong as the amine blush. I find that the easiest method is to purchase a high-quality resin that is not so susceptible to amine blush and use peel ply. By doing this, I get the best of both worlds. I get a resin that is easy to work with and has higher qualities in virtually every area, and I reduce sanding work and lighten my laminate by using peel ply. With these issues in mind, this is why we only use Hexcel's EPOLITE 2183,2184,2187 hardeners which eliminate the problem of amine blush. We at AeroCad had bad testing results on the Amine Base hardeners. On a glass to glass bond ( tape glassing cured bulkheads in place on to other cured glass) the tape glass would peal off like it bonded to wax paper. We also found plies of glass after full cure, to also have poor peel strength between the plies. Vacuum bagging also produced the same reaction. We deal with 80 to 90 percent humidity in our area most of the time. We feel that you should (always test your resin systems) to see if these types of problems come up. Most of our peel strength problems were seen in the winter time. The longer the cure rate (slower hardeners), the more moisture that seemed to creep in. We had material reps. see what problems we were seeing in our testings, and to our surprise no answers came from them. Our fix is to just use Styrene-Monomer Base hardeners. What happens if we can no longer get this material? --ryntpkjljsyvnfxvkljclfrdrsckui-- Date: Mon, 26 Feb 1996 08:07:37 -0500 From: william l kleb Subject: Re: Resin users Warning............. Jeff S. Russell writes: > > (DO NOT USE EPOXY PUMPS) back to the weighing method? that sounds depressing. > We at AeroCad had bad testing results on the Amine Base hardeners... > Humidity in your fiberglass and core material can also produce > reactions on how a laminate will turn out. > to what extent? this seems to fly in the face of burt's original honey and bed sheets idea of airplane-building that even idiots couldn't mess-up. is amine something that has been introduced since the original RAE epoxies? --- bill kleb (w.l.kleb@larc.nasa.gov) 73 bellanca 7gcbc citabria 99 kleb cozy iv Date: Mon, 26 Feb 1996 16:37:35 -0800 From: aerocad@ix.netcom.com (Jeff S. Russell) Subject: Re: Resin users Warning............. remember Bill, RAF is in the desert with almost no humidity Use all resin as if your the Guinea-Pig in your area. With this in mind you will find the resin that works the best for you. Date: Mon, 26 Feb 1996 16:58:36 -0800 From: aerocad@ix.netcom.com (Jeff S. Russell) Subject: Fwd: Re: Resin users Warning............. ---- Begin Forwarded Message Jeff S. Russell writes: > > (DO NOT USE EPOXY PUMPS) back to the weighing method? that sounds depressing. > We at AeroCad had bad testing results on the Amine Base hardeners... > Humidity in your fiberglass and core material can also produce > reactions on how a laminate will turn out. > >to what extent? this seems to fly in the face of burt's original >honey and bed sheets idea of airplane-building that even idiots >couldn't >mess-up. is amine something that has been introduced since the >original RAE epoxies? remember Bill, RAF is in the desert with almost no humidity. Use all resins as if your a Guinea pig in your area. test, test, test untill you know the resin will work for needs in your area. We also found that the TG was not always what the Resin Manufacture said it was. We took nose struts made out of S-2 glass and sample Resin from manuf. and post cured, slowly stepping up to 190 deg. We would then let cool, and reheat to 160 then 170 and so-on untill the resin became rubbery. Some would only reach 160, and others maybe 180. Our the Resin Manuf. lying to us as end users. They told us to expect 10-20 percent less TG becouse we were not in THEIR lab. If that's the answer that you can expect from them. You best TEST - TEST - TEST Date: Tue, 27 Feb 1996 05:06:14 -0800 From: aerocad@ix.netcom.com (Jeff S. Russell) Subject: Fwd: Re: Resin users Warning............. ---- Begin Forwarded Message To: aerocad@ix.netcom.com (Jeff S. Russell) From: Greg Smith Subject: Re: Resin users Warning............. Dear Jeff, I concur with your opinions on the amine based products....have also gone back to 2410/2184 system. That 2427 stuff just isn't what it's cracked up to be, at least in my neighborhood. I didn't have much luck with soap and water to remove heavy deposits of the blush (when I used 2427); chipping it off with a scraper and then following up with a good sanding seemed to do the trick, although a lot of tedious, unnecessary work (if I had used the right stuff in the first place). Just thought I'd drop you a note and let you know that all the cores, spars and strakes arrived with no damage to the parts. A little shipping rash here and there from handling in a warehouse but everything checked out fine upon unpacking. I am very impressed with the quality of these parts....you guys do great work! Thanks again for handling that little last minute freight bill misunderstanding.... Best Regards, Greg Smith Date: Tue, 27 Feb 1996 15:55:50 -0500 (EST) From: Tech Support - Rick Subject: Re: Fwd: Re: Resin users Warning............. I am using 2427 here in Raleigh, NC. The only problems I had initially, were the fact of the long cure time and gumming in the first 24 hours. After that it cured totally hard with no peel. But, I solved that with a parts bake oven. four hours and hard cure. my thoughts are my own and all that jazz. but anyway, gotta go, flying and scuba diving jerk my chain. Rick Date: Wed, 06 Mar 96 12:05:34 est From: "Larry Schuler" Subject: 2427 Epoxy Anyone used both RAE and 2427? What are the key differences? I am planning to do complete MKIV with 2427 unless some of you "experienced" forlks can tell me why I might re-consider. My understanding is that 2427 is easier to work with and can be post cured @ about 160 Deg. Thanks for advice in advance. Larry Date: Wed, 6 Mar 1996 19:08:34 -0500 From: JQUESTCOZY@aol.com Subject: Re: 2427 Epoxy I used RAE "fast" up until the nose section when Wicks informed me they would no longer carry it. Some comparison: Advantage:The 2427 I would say wets out a little better (more or less viscous, I get them mixed up, anyhow, flows nicer) Disadvantage: 2427 is a little more transparent where RAE fast was "greenish" It seems more difficult to spot lean areas or bubbles with the 2427. It takes longer to cure than what I'm used to with the RAE. I could normally do a layup over a piece I did the day before with RAE, 2427 still will not sand without gumming the sandpaper. Should you switch? One better than the other? I think you'll get a lot of opinions, either one is fine. If I knew Wick's would start to carry RAE again or never stopped I most likely would be still using the RAE. Just my 2 cents worth. You can check the archives on the subject of epoxy for further experiences from other builders.:-) John Wilemski (JQUESTCOZY) Date: Thu, 7 Mar 1996 00:30:01 -0500 From: JHocut@aol.com Subject: Re: 2427 Epoxy I've been using 2427 and have no complaints at all with it. I understand how a few people like a resin system that cures faster, but I personally find the fact that 2427 cures slower to be a blessing. I get the temperature in my shop down to 65 - 70 and have plenty of time to do layups, then crank it up to about 80 to speed up cure. Lately instead of heating the entire shop to 80 I've been aiming shop lamps w/ a 75 or 100 watt bulb at the area that needs to cure, this gets the local area up to about 120 or 140 and really speeds up cure (and the resin cures stronger than at room temperature from what I understand). I've heard of some people having a problem w/ 2427 in that after several hours you can't add to a layup because of poor adhesion (that's been discussed here a couple of times - I've noticed that the resin in a container will "skin" after a sufficient length of time, I believe that's what's happening in these layups also). The solution is to plan ahead, and wherever you can't get the next layer of glass on in a couple of hours peel ply and finish the next day. I've also worked w/ some of the other resin systems, and find the smell of 2427 to be MUCH less objectionable (virtually nonexistant in fact). 2427 wets out a bit better also, because of it's lower viscosity. To make a short story long, I think 2427 is just great, and have had no problems at all with it. Jim Hocut Cozy IV # 448 Date: Thu, 07 Mar 1996 07:30:43 -0600 From: tims@enet.net (Tim Sullivan) Subject: Re: 2427 Epoxy "Larry Schuler" writes: > What are the key differences? > > I am planning to do complete MKIV with 2427 unless some of you > "experienced" forlks can tell me why I might re-consider. > > My understanding is that 2427 is easier to work with and can be post cured > @ about 160 Deg. I, like many others,am using 2427. I started with safety epoxy II but switched after the first gallon. The 2427 is easy to work with BUT terrible with locating stray air bubbles esp under peel ply. my $0.02 Tim Sullivan (tims@enet.net) Phoenix, AZ | * | Cozy MK IV Builder #470 |-----(/)-----| The journey begins 8/10/95 / \ Current Status: Ch 9 o o Date: Thu, 7 Mar 1996 09:45:00 -0500 From: Dick.Finn@FNB.sprint.com Subject: Re: 2427 Epoxy I used RAE through the whole process. It has a bluish green color which makes it easier to spot dry spots or bubbles on the layup. I understand 2427 is transparent. This, to my way of thinking, is not a show stopper but is a major advantage. The RAE is nearly odorless. Again, not a show stopper but when working in the basement it is a big plus. I friend who uses Safty-poxy had his wife evict him from his basement due to the smell. He is now working in the garage. Even though it is heated it still gets chilly out there in a Chicago Winter. I'm not sure but I believe the RAE is more toxic. I do take great care with barrier creams and gloves. Dick Finn Cozy Mark IV #46 ______________________________ Reply Separator _________________________________ Subject: 2427 Epoxy Author: lschuler@cellular.uscc.com at INTERNET Date: 3/6/96 2:04 PM Anyone used both RAE and 2427? What are the key differences? I am planning to do complete MKIV with 2427 unless some of you "experienced" forlks can tell me why I might re-consider. My understanding is that 2427 is easier to work with and can be post cured @ about 160 Deg. Thanks for advice in advance. Larry Date: Thu, 07 Mar 96 10:42:57 est From: "Larry Schuler" Subject: Re[2]: 2427 Epoxy Neat idea with the heat lamps. I am in Wisconsin, similar shop heating problems.... finished building the shop in December. I keep it at about 45 or 50 (currently inactive) and wife is already complaining about the gas bill! [Wait till she sees next winter's bill] Wouldn't the lamps cause some hot-spots {un-even heating}? I was thinking about making a heat box (oven) out of insulating wall board and use a fan-driven space heater (electric), or similar, to circulate and even out the temp with some strategicly placed thermostats and a step-up controller (which I will make myself). I talked with Gordon and Bailets at length last Oshkosh and both had suggested that a post cure @ about 160 Deg is right for the foam/epoxy (2427) and would push the finished Tg up well over 250 Deg. Gordon said NOT to raise the temp more than 5 deg per minute; and was refering to "POST-CURE", not the initial cure. This all translates to the possibility of something other than white paint on the finished plane {but not black} while not having to worry about sagging wings when parked in the Arizona sun. Bailets suggested the insulation board; said he uses it all the time. Anyone tried vaccum bagging? I know it will cost a bit more, but maybe help with weight a bit and help with the "Blush" problems. Larry ______________________________ Reply Separator _________________________________ Subject: Re: 2427 Epoxy Author: JHocut@aol.com at INTERNET Date: 3/7/96 12:33 AM Lately instead of heating the entire shop to 80 I've been aiming shop lamps w/ a 75 or 100 watt bulb at the area that needs to cure, this gets the local area up to about 120 or 140 and really speeds up cure (and the resin cures stronger than at room temperature from what I understand). Jim Hocut Cozy IV # 448 From: Marc J. Zeitlin Subject: Re[2]: 2427 Epoxy (fwd) Date: Thu, 7 Mar 96 18:32:55 EST Larry Schuler wrote: > .............. I talked with Gordon and Bailets at > length last Oshkosh and both had suggested that a post cure @ about 160 Deg > is right for the foam/epoxy (2427) and would push the finished Tg up well > over 250 Deg. Gordon said NOT to raise the temp more than 5 deg per > minute; and was refering to "POST-CURE", not the initial cure. Wow - this seems to go against everything Gordon Bowen said in his lecture their, as far as I remember. I got the impression (and I talked to him individually for about 1/2 hour) that there was some maximum Tg that you could get with a particular epoxy, and that it would be about 40 deg. F above the post-cure temperature, up to some maximum. I got the impression that the maximum for the epoxies we use (RAE, SP, etc.) are all about 170 deg F, so that postcuring above 130-140 deg F wouldn't get you anything. I've NEVER heard anything as high as 250 deg F. I'd really like to see something documented on this, rather than just Larry and I trying to remember what someone else said 8 months ago. > ............. This all > translates to the possibility of something other than white paint on the > finished plane {but not black} while not having to worry about sagging > wings when parked in the Arizona sun. I wouldn't chance it. I'd like to stay as far away from Tg as I can, especially if the max. Tg is 170 deg. F. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Fri, 08 Mar 1996 08:44:23 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: Re[4]: 2427 Epoxy (fwd) >Wow - this seems to go against everything Gordon Bowen said in his > lecture their, as far as I remember. I got the impression (and I talked > to him individually for about 1/2 hour) that there was some maximum Tg > that you could get with a particular epoxy, and that it would be about 40 > deg. F above the post-cure temperature, up to some maximum. I got the >impression that the maximum for the epoxies we use (RAE, SP, etc.) > are all about 170 deg F, so that postcuring above 130-140 deg F > wouldn't get you anything. I've NEVER heard anything as high as 250 deg F. I'd >really like to see something documented on this, rather than just Larry >and I trying to remember what someone else said 8 months ago. Its interesting that we found on our testing of Tg on each epoxy that we tried was around 160 to 190 deg. The only epoxy that we found to have a higher one was the Epolite systems. It had a max. Tg of 250 deg. F. We asked the Hexcels lab on what's the differents on them and we got the answer that this systems seems to super harden when it reaches this temperature. This resin system states its Tg is 190 deg. Is this a good find, insted of what seems to be the normal LESS THAN (what they say it will do). I think this gives us a better pucker facter then other systems if heat is an problem. We now only use this in our Main gear struts for fear of the dreaded heat. hope this helps AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Fri, 08 Mar 1996 07:40:29 -0600 From: tims@enet.net (Tim Sullivan) Subject: Re: Re[2]: 2427 Epoxy (fwd) Marc wrote: >Wow - this seems to go against everything Gordon Bowen said in his lecture >their, as far as I remember. I got the impression (and I talked to him >individually for about 1/2 hour) that there was some maximum Tg that you >could get with a particular epoxy, and that it would be about 40 deg. F >above the post-cure temperature, up to some maximum. I got the >impression that the maximum for the epoxies we use (RAE, SP, etc.) are >all about 170 deg F, so that postcuring above 130-140 deg F wouldn't get >you anything. I've NEVER heard anything as high as 250 deg F. I'd >really like to see something documented on this, rather than just Larry >and I trying to remember what someone else said 8 months ago. I have to agree with you marc. I took the Alexander Advanced Composites course and they reiterated that about 40F above cure temp is all you can safely apply before a "melt" down starts. Stay with white wings (esp. me here in AZ). Tim Sullivan (tims@enet.net) Phoenix, AZ | * | Cozy MK IV Builder #470 |-----(/)-----| The journey begins 8/10/95 / \ Current Status: Ch 9 o o Date: Fri, 08 Mar 1996 15:32:17 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: [7]: 2427 Epoxy Larry S. asked: >Is the 250 Deg max Tg for Epolite you mentioned obtained by elevated >temperature cure/post-cure, or room temp cure only? Post cure only. >If elevated cure/post-cure, could you describe the method/step/ramp >etc. that you use? We have a 500 deg. oven. We let the part (one day) cure at room temp. Insert in oven at 120 deg. for 2 hours, then we go to 140 deg. then 160, 180, 200, two hours at a time thus (the ramp process) This is a 10 hour oven job. We let the part slowly go down in temp. (A day later, To check what we now have for Tg). Raise the temp back up to what softens the harden resin and (presto) You found the max temp. Tg AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Fri, 08 Mar 96 11:55:51 est From: "Larry Schuler" Subject: Re[6]: 2427 Epoxy (fwd) Jeff, Thanks for your input; you have been a very welcome addition to this group. I believe the higher Tg you described was what Gordon was referring to; but, I am fairly certain that the Tg wouldn't go that high without a post-cure. In other words it is of little benefit until, for example, the gear legs get hot once (hopefully 'before' being mounted on the plane). Is the 250 Deg max Tg for Epolite you mentioned obtained by elevated temperature cure/post-cure, or room temp cure only? If elevated cure/post-cure, could you describe the method/step/ramp etc. that you use? Thanks Larry Date: 09 Mar 96 07:12:30 EST From: "William E. Buckley" <74744.2301@compuserve.com> Subject: Epoxy I was wondering how much of a difference it makes on a layup if the temperature is allowed to fall over night. Will the strength be harmed if I let the garage fall back into the 40's overnight after finishing a layup? It obviously cures slower. I'm using 2427 by the way. I've never read anything saying this creates a weaker structure; just a slow curing one. Wishfull thinking on my part or not? William E. Buckley #437 74744.2301@compuserve.com From: Marc J. Zeitlin Subject: Epoxy (fwd) Date: Mon, 11 Mar 96 9:13:09 EST William E. Buckley asks: >I was wondering how much of a difference it makes on a layup if the >temperature is allowed to fall over night. ......... I've never read >anything saying this creates a weaker structure; just a slow curing one. You've got it right - just slower. Cured is cured, within the temperature ranges we're discussing. Assuming that you eventually post-cure all the stressed components (like you should), you would have no measureable strength difference in your parts (actually, even if you DIDN'T post-cure, eventually the parts would be identical). -- Marc J. Zeitlin Email: marcz@an.hp.com From: Michael Antares Subject: RE: Epoxy Date: Mon, 11 Mar 1996 09:05:01 -0800 I was wondering how much of a difference it makes on a layup if the = temperature is allowed to fall over night. Will the strength be harmed if I let the = garage fall back into the 40's overnight after finishing a layup? It obviously = cures slower. I'm using 2427 by the way. I've never read anything saying this = creates a weaker structure; just a slow curing one. Wishfull thinking on my part = or not? William E. Buckley #437 I'm not providing any answers but can add a comment that I'm doing the = same thing. Some structures that I've done a long time ago seem to be = cured just fine although they did go through the cool night routine. I = do however warm the garage up to at least 60 degrees while I'm doing the = layups (I'm using 2426 epoxy). To add a comment on the high temperature cures. Going back to my = aerospace days including man-rated NASA equipment, epoxies were cured at = 140 degrees for maximum strength. AND I do not purport to be any kind = of a knowledgeable person in this regard--this is only anecdotal = evidence! Michael Date: Mon, 11 Mar 1996 18:19:48 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: Epoxy >I was wondering how much of a difference it makes on a layup if >the temperature is allowed to fall over night. Will the strength >be harmed if I let the garage fall back into the 40's overnight after >finishing a layup? It obviously cures slower. I'm using 2427 by the way. >I've never read anything saying this creates a weaker structure; >just a slow curing one. Wishfull thinking on my part or not? > >William E. Buckley #437 Don't forget that the longer it takes to reach the jell time (B stage) the more moisture that can be picked up in the layup. If you are using slow hardeners or just in cooler climates where temps can be a problom. Use a plastic drop cloth (like a tent) and a room heater. You will see much better curing times with little cost needed to do this. This will some what post cure your parts Better than none? AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Mon, 11 Mar 1996 18:44:28 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: Epoxy I forgot to add that we are TRYING some different PTM&W reasin systems. They are still trying to get us to use their stuff. We made some small parts and let them cure overnight turning the heat down to 55 deg. We also made some small parts that were made from 2410/2184. the same time. The next morning the PTM&W was almost still wet and the 2410 system was hard as a rock. The heat was turned on to 70 deg. for at least 8 of our working hours and the P resin still only got to B stage. Two days later. The same thing. On the forth day we post cured the P parts to 140 deg., and it got hard after the oven bake. PTM&W Called me today and asked me what I thought and after telling him what the coolness did he said that that resin system NEEDS post curing. Nice to now know? hope this helps AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Mon, 18 Mar 96 19:10:26 est From: "Larry Schuler" Subject: Re[5]: 2427 Epoxy (fwd) On 8 Mar 1996, Bill Walsh wrote: >Just a note....a story Stan Montgomery told me was about his experience in trying to get the optimium in post cure. He elevated the heat over 180 degrees for quite a few hours ...only to find that he had melted all of the foam. 250 degrees seems excessive. I post cured to 140 degrees per Stans recomendations. Bill Walsh >>Bill, I'm not surprised it turned to mush on him since the blue foam Tg is 180 Deg. That's why Gordon recommended 160 Deg post cure as highest safe temp for epoxy/foam combo most of us use. Also not more than 5 deg rise per minute helps to prevent hot/cold spots {slower rise is ok, but faster is a bad thing}. Date: Tue, 19 Mar 1996 22:18:56 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: [6]: 2427 Epoxy (fwd) >On 8 Mar 1996, Bill Walsh wrote: >Just a note....a story Stan Montgomery told me was about his >experience in trying to get the optimium in post cure. He >elevated the heat over 180 degrees for quite a few hours ...only to find >that he had melted all of the foam. 250 degrees seems excessive. I >post cured to 140 degrees per Stans recomendations. Bill Walsh >Bill, I'm not surprised it turned to mush on him since the >blue foam Tg is 180 Deg. That's why Gordon recommended 160 Deg post cure >as highest safe temp for epoxy/foam combo most of us use. Also not more >than 5 deg rise per minute helps to prevent hot/cold spots {slower rise >is ok, but faster is a bad thing}. AeroCad writes: Don't forget that the PVC foams can take a much higher temp. 290 + to bend or reshape. The Last-a-foam also has a higher temp than the Extruded PS foam thats in our wings/canards. So if you are post curing wings/canards 140-150 max so not to cook the foam. We also heard of a Cozy having a heat meltdown in the wing and main spar becouse of an exhaust crack of some sort. The repair was to replace the melted foam and glass with pour foam and new glass. My question is what about the resin that got baked at 300 + deg on the rest of the main spar and wings. It sounded like the main spar got at least this high becouse the 6 lb PVC foam was twisted when removed. The Resin degrades to being britle this far past Tg? I think to be on the safe side that new wings/main spar would need to be replaced, insted of repaired as such. Does any of the Resin Mfg have a high temp resin test to see if its OK if it gone past its Tg by 100s of deg. I would like to hear from them to keep this person safe than sorry. AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Thu, 21 Mar 96 07:52:09 est From: "Larry Schuler" Subject: Re: 2427 Epoxy (fwd) Sorry this took so long; was out of town over a week. Finally found a few of my notes (in my wallet.... I'd say under my nose, but that would be realy "stretching" it). First a few caveats: 1. I have not started yet. 2. I purchased plans set #500 (nice number and milestone for Nat). 3. I have some materials ordered. 4. My name is Larry Schuler and I live in Wausau, Wisconsin; please don't confuse me with some "bad vendor named Larry in Wisconsin"; I don't sell anything; but, I will gladly give away my experiences for the learning benefit of others (I tend to make some really dumb mistakes, so I try to get very cautious, but tend to learn more from the dumb ones). 5. I have not TESTED anything yet; at this point all I can do is repeat what I have learned from those experienced folks that have been there. My notes were from lengthy conversations I had with both Bowen and Bailets outside the forums {Sorry, my notes don't say which one said what}. The discussions were centered around epoxys and how to get a higher Tg to combat sag. They both said that sag should not be a problem with 2427 as long as the plane is white and has a good UV primer. Here are my notes (verbatum) take 'em for what they are worth; they seem to "generally" agree with what Jeff has posted here. - Use 2427 newer formula than RAE - saftypoxy ok if necessary but not as good - 2427 better stress comp., tens., + tough. [I was refering to Tension, compression and toughness] - higher Tg at cure - easier to wet out - hard to get bubbles out - pay attention - vac bag if possible - gets bubbles out and excess resin - post cure at 140 to 160 - 160 cure gets ~ 240-250 Tg [glad I found the note; doesn't say "well over 250" as I stated before {one of those 'dumb mistakes' I was talking about}] - step or ramp <= 5 deg/min - hold high temp for even heating (1/2 - 1 Hr) - Ramp/step down - no shock/spot cool - Tg blue styro is ~180, be careful melt-down - all other foams in czy >180 Tg - cheap oven use insul. sheath - heat lamps spotty - circulate heat evenly - indirect heat source (not on one spot) - test EVERYTHING! Thats what I have for what it's worth. I intend to "try" (ie. experiment and test). My main goal is to reduce the chance of sag over the years so I don't always have to worry about hanger space. There may be a "possible" side benefit of "maybe" using a color other than white. The last note I took from them says it all...... I will be more than happy to share what I learn along the way. Larry Date: Thu, 21 Mar 1996 18:03:22 -0800 From: harvey3@ix.netcom.com (Neil K. Clayton) Subject: 2427 "Epolite" warning I bought 2 gall of 2427 Epolite from Wicks about 2 weeks ago. I didn't use it immediately 'cos I still had some 2410 left. Yesterday I cleaned my dispenser thoroughly and went to refill it with 2427. I noticed the hardner can was cloudy and had what appeared to be crystals floating in it. I examined it further by cutting the top off the can with a can-opener instead of peering through the cap hole. It was still the right orange colour, but had a skin on the top and particles floating in it. It was too opaque to see the bottom of the can. It didn't feel right, so I called Wicks. Long story short, I got a run around (Rosalie; "it'll be a few days before I can get back to you..." - not like Wicks) so I called Hexcel direct. Spoke to a chemist called Eric someone. He said he knew what it was....it had been contaminated with carbon mon (or di-) oxide from the atmosphere because it didn't have nitrogen pumped into the can above the liquid after manufacture. He said don't use it! He'd have Wick's called and tell 'em. I checked the other can I bought and it was the same. Batch number CEHE066 Don't use it if you have any. Neil Date: Fri, 22 Mar 1996 14:31:46 -0500 From: william l kleb Subject: 2427 epoxy humidity effects (was Re: (2) 2427 warning) Jeff Russell writes: > > This is the same thing that will happen when you leave this type resin system in a > epoxy pump exposed to humidity. As soon as you open the container (Time is ticking) > i am confused by this... why is keeping your epoxy in the can any better than an epoxy pump reservoir? an epoxy pump is sealed as good as any can, except for the small bit exposed in the end of the dispensing tube. are you suggesting that the humidity travels up the tube, contaminating the entire reservoir? couldn't one just "pour-off" the first bit in the dispensing tube as one does with any soft-serve ice cream machine? according to your statement, it seems that once you open a can of resin, you have to use the entire thing very quickly, because you have let "regular", humid air in the can, just as when you refill an epoxy pump. maybe we have to buy a bottle of argon (or some suitable inert gas), and back-fill the epoxy pump reservoir (or can) before we re-seal it? my earlier point about rutan and his philosophy of "even an idiot can do this and not go too wrong" was that i am surprised that RAF would un-categorically approve a resin system, say 2427, and not have considered humidity effects. i know they are located in the desert, but they usually seem to have a very open, safety-conscious, global outlook. maybe the word just hasn't gotten to them yet? regardless, your point of test, test, test is well taken. --- bill kleb (w.l.kleb@larc.nasa.gov) 73 bellanca 7gcbc citabria 99 kleb cozy iv Date: 23 Mar 96 22:22:00 EST From: "Edmond A. Richards" <103235.1336@compuserve.com> Subject: 2427 Epoxy humidity effects On March 22nd Bill Kleb writes: An epoxy pump is sealed as good as any can.... -------------------------------------------------------------------------- The epoxy pumps that most of us are using have only "Tupperware" style containers to hold both the resin and the hardner. This seems to me to be far less a container than the metal can that the material is distributed in. Also if you look closely, there is a hole in the lid of each container to let air in as the resin is drawn down. As far as moisture sensitivity of the 2427 epoxy. I became conserned when I read the caution statement on the can. It clearly states if the can is opened, the air that is introduced into the cotainer must be diplaced with dry nitrogen before re-capping. This conserned me enough to replace the "tupperware" tanks on my epoxy pump with metal cans with sealed lids and a dry nitrogen purge. ( I live in Florida, moisture is a way of life). I only used about 1 1/2 gal. of the 2427 then switched back to Safe-T-Poxy II. While using the 2427 I saw many of the problems that Jeff Russell describes in his discussion of the subject. I don't feel too bad about the parts I made with the 2427 because at the time I was working mostly on the interior (seats, armrests, etc.) and micro for filler. The only major pieces I made with it were the winglets. Although I did use Safe-T-Poxy II to attach them to the wings. I'm sure the 2427 epoxy is OK but I just didn't feel right about using it. However I still have the metal tanks and the nitrogen purge system on the ratio pump. It keeps the Safe-T-Poxy II just as fresh as a daisy for months. Date: Mon, 25 Mar 1996 08:55:34 -0500 From: Phillip.Johnson@Lockheed.on.ca (Phillip Johnson) Subject: 2427 Epoxy humidity effects Edmond A. Richards writes: > This conserned me enough to replace the "tupperware" tanks on my > epoxy pump with metal cans with sealed lids and a dry nitrogen > purge. ( I live in Florida, moisture is a way of life). I took a different approach: After I fill the "Tupperware" tanks I place a plastic bag over the open top then replace the lid of the tank. The bag is sufficiently large to completely fill the container when it is empty. The bag is arranged to be on top of the resin/harder at the time of filling. As the fluid is used, the bag moves down to fill the void without introducing more air over the fluid. The resin is always fresh and doesn't need fancy Nitrogen etc. Phillip Johnson Date: Tue, 26 Mar 1996 22:31:52 -0500 From: Fritzx2@aol.com Subject: 2427 Hardner Batch CEHE066 In a message dated 96-03-24 part of Neil Clayton's response to John Wilemki: > It was a chemist at Hexcel who >told me not to use it. His name was Eric (something). Hexcel's # is >(818) 882-3022. He did not specifically say "don't use batch #CEHE066" >but DID tell me not to use the bad stuff I'd received. You might want >to call Eric yourself about the entire batch. It sounded like the stuff >went bad during manufacturing. I too recently (in the last couple of weeks) got a 1 gallon kit of 2427 from Wicks. After reading the message from Neil that he had some bad hardner, I checked my hardner. Mine did not have a skin on the top nor did I see any crystals suspended. The color was as usual, and I could see all the way down to the bottom of the can while shining a light down through the hole. I did however see some very thin layer of sporatic milky clusters on the bottom of the can about 1/8 " thick the size of a dime. To tell you the truth, I never really looked inside the hardner can before so I don't have anything to compare these observations against. I think I will from now on when I get a new can. Since I do not use a pump and must rely on the can to contain the hardner, I therefore cannot "pop the top". I drew a 4 oz. sample and inspected it closely. I could not see any abnormalities. Has anyone else who got this batch inspected theirs? If so, what did you find? I am about to glass the fuse bottom with this batch of resin and hardner and would hate to find out afterwards that there was a problem even though I couldn't tell by looking at it. I'll probably give the Hexcel rep. a call tomorrow also. John Fritz Fritzx2@aol.com Date: Fri, 29 Mar 1996 12:16:23 -0500 From: JHocut@aol.com Subject: Re: 2427 from Wicks In a message dated 96-03-28 23:09:30 EST, HARVEY3@IX.NETCOM.COM wrote: >Funny stuff...I've never used it before. No smell, & when mixed with >flox or micro it looks the flower & water glue we used for papier mache >when we were kids. Seems to go "off" in a hurry - I laid some up at >4.00PM and it was hard enough to prod by 9.00. I've pretty much been using 2427 exclusively, although have used a little Safe-T-Poxy and some West (not for structural stuff, of course). The biggest factor in how fast 2427 (or probably any epoxy for that matter) sets up is temperature. If I'm doing a big layup and need plenty of time I'll get it down to about 65 to 70 in my shop (small shop so it's easy to control temp), and I've got plenty of time. Want it to cure faster to be able to work on something, crank the temperature up. Like Nat says in the plans, temperature is an important tool at your disposal, and be sure to have a wall thermometer in your shop. BTW, if you want to see FAST - try the West with the fast hardener at about 80 to 85 degrees. You've got about 10 minutes to do what you need to do, it's hard in a couple of hours. Jim Hocut jhocut@aol.com Date: Sat, 30 Mar 1996 12:32:57 From: JRaerocad@gnn.com (Jeff Russell) Subject: new epoxy I have used the replacement EZ83 / EZ10 this replaces Safty- epoxy (I). It seems to work the same as the old stuff. Same thickness, yellow color instead of brown or brownish green. cures the same time, no blush at 90% humidity. need to do Tg testing ASAP Things look good so far. AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Mon, 01 Apr 1996 14:41:13 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: "Hard Shell" Layups Jim Hocut writes: >2) In regards to final finishing, does West or Alphapoxy have any >advantage over 2427 (besides the fact that Alphapoxy costs a little less)? The West systems come in fast or slow hardeners. Alphapoxy and 2427 only has one speed. The west sys. seems soft when cured (If I can print it with my thumb nail, Its too soft) Alpha and 2427 don't have this problem. Alpha is cheaper and EZer to sand with no (bad drugs) inserted to get this result. I have heard that RAF disapproves using alcohol with Epoxy resin. Its degrading strength. Alcohol with the use of micro where strength is not an issue should not be a problem. >Obviously the point would be reached where the strength of the resulting >material would be unacceptable. Ditto on that: AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Mon, 01 Apr 1996 16:57:31 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: layups colors >Have you or do you know of anyone who has tried adding a dye/color >to 2427 to help with the bubble problem? Tim, Hexcell told us that an additive could be used. They had one, but I don't remember what it was called. I sure that Gorden B. knows. PTM&W always used dye when we ordered from them. (dark brown) I have also used food color (one drop per 10 oz.) AFTER I MIXED the resin/hardener together so it had some color. I could not tell any differance in the epoxy after it cured. hope this helps AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com From: "Daryl H. Lueck" Subject: mixing RAE hardners Date: Fri, 5 Apr 1996 13:36:25 -0000 I'm all set to cover the second wing this weekend and discovered I won't = have enough RAE Slow hardner. I've got about half a quart in the pump, = not enough to finish the top of the wing. =20 I have 3 quarts of the RAE Fast though. Here's the question du-jours: Can I mix RAE Fast and RAE Slow in the pump, or do I need to clean the = pump after using up the slow? Can I use up the Slow on the first 2 glass layers, then use the Fast for = the third layer? Is it ok layup fast over slow or do the layers have to = cure first???? Help!!!!! Thanks much, Daryl Lueck Cozy Mark IV #243 Date: Sun, 7 Apr 1996 09:29:29 -0400 (EDT) From: Tech Support - Rick Subject: Re: mixing RAE hardners Clean the pump, because , otherwise, your cures go wierd. But it is permissible to layup over the slow with the fast. Rick > > I have 3 quarts of the RAE Fast though. Here's the question du-jours: > Can I mix RAE Fast and RAE Slow in the pump, or do I need to clean the pump after using up the slow? > > Can I use up the Slow on the first 2 glass layers, then use the Fast for the third layer? Is it ok layup fast over slow or do the layers have to cure first???? > > Help!!!!! > Thanks much, > Daryl Lueck > Cozy Mark IV #243 > > Date: Mon, 8 Apr 1996 18:55:01 -0400 (EDT) From: Tech Support - Rick Subject: Alcohol and epoxy dangers! Gentlemen, A word of caution from the materials science dept at NC STate Univ. I checked into this idea of epoxy and alcohol together. The response was overwhelming against the idea at all. These reasons being were similar. 1) alcohol can through gloves were epoxy can not. Also, if the alcohol/epoxy mixture were to get to the skin, the alcohol will induce the epoxy straight to the blood stream, precipatating an alllergic reaction onset faster than normal. 2) Alcohol also outgasses very quickly. This gas formation with the epoxy outgas also leads to extreme sensitivity to epoxy odors. 3) Alcohol seriously degrades almost all known epoxy, whether cured or uncured. Read this in strength, tensile, and elasticity abilities. That is what I have learned, more later as I uncover it. Rick Crapse 919-851-1557 Date: Mon, 8 Apr 1996 19:11:40 -0400 From: Fritzx2@aol.com Subject: Re: Safe Epolite 2427 disposal Harvey3 wrote about disposing of his 2427 epoxy: >Any known neutraliser? I could call the state Haz Mat people but I can >imagine how that conversation will go.... You have what you need right there. Mix the stuff in small enough batches so as not to cause a high heat reaction. It might not be good enough to provide the proper strength for your project but since you are only going to toss it anyway, my guess is that it will cure well enough to prevent any hazard. By the way, this is what I do to the little remaining bit I have in each set of cans in order to be a little more friendly to the environment. John Fritz Fritzx2@aol.com From: Marc J. Zeitlin Subject: Alcohol and epoxy dangers! Date: Tue, 9 Apr 96 8:48:38 EDT Rick Crapse writes: >I checked into this idea of epoxy and alcohol together. The response was >overwhelming against the idea at all. These reasons being were similar. While I do not disagree with the facts, I disagree with the conclusion. Here's why: >1) alcohol can through gloves were epoxy can not. Also, if the alcohol/epoxy > mixture were to get to the skin, the alcohol will induce the epoxy > straight to the blood stream, precipatating an alllergic reaction onset > faster than normal. No question. Any solvent (Acetone, MEK, etc.) will do the same. This is why I use Butyl gloves (for chemical resistance) with vinyl gloves (for butyl glove protection) over them. > 2) Alcohol also outgasses very quickly. This gas formation with the >epoxy outgas also leads to extreme sensitivity to epoxy odors. Also true. This is why I ALWAYS wear a carbon filter respirator while working with epoxy. > 3) Alcohol seriously degrades almost all known epoxy, whether cured or > uncured. Read this in strength, tensile, and elasticity abilities. This may be true, but if tests show that peel strength from glass to foam is NOT degraded from the plain (non-alcohol diluted) case, then there is no net loss. A chain is only as strong as it's weakest link, right? If the foam is that link, making the epoxy stronger doesn't help. So far, the evidence seems to show that peel is better, not worse, with hard shelling, even with the alcohol in the epoxy. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Mon, 29 Apr 1996 20:59:50 -0700 From: Eric Westland Subject: Re: COZY: Re: 2427 Hardner Batch CEHE066 John, thanks for the response. When I opened the can, it was crystal clear. I did the top strake layups yesterday and they cured rock hard - all is well. eric Fritzx2@aol.com wrote: > > In a message dated 96-04-28 13:47:22 EDT, Eric Westland wrote: > > >I just got a batch of the same. What did you resolve on this - did the > >harner work fine? Did you call Hexcel and if so, what did they say? I > >have not opened the cans yet, so if there is a problem, I would like to > >know. > > I contacted the Hexcel rep. He informed me that if the hardner > was not milky then there was no problem. My particular > can of hardner was just fine. I will always carefully look > inside though before using a new can. Since I don't use > a pump I hadn't looked inside before. I would have noticed, > I'm sure, when I poured it into my cup at time of use but that > would have been a BAD time to find out in the middle of a layup. > > John Fritz Fritzx2@aol.com From: UYFA59A@prodigy.com ( JAMES J CULLEN IV) Date: Tue, 28 May 1996 11:48:24, -0500 Subject: COZY: Fiber-Resin Lot #CEHE066 -- [ From: James J. Cullen, Ph.D. * EMC.Ver #2.10P ] -- It was with considerable interest that I followed the series of discussions regarding the alleged `bad batch' of Fiber-Resin's Epolite 2427 Epoxy bearing lot number CEHE066 -- especially as I had purchased four gallons of the material in preparation for constructing my wings. As the discussion progressed, it became apparent that no resolution was ever reached as to whether the lot in question was actually bad. Neil Clayton had his material replaced by Wicks with material from the same lot number and Neil reported that the replacement material appeared to be good. John Fritz observed crystals clumped at the bottom of one of his hardener cans and wondered whether this was a problem. Without a definitive statement from Fiber-Resin or Wicks, I was reluctant to use the material I had received and no-one ever posted a final resolution of the matter to our discussion group. Accordingly, I called Wicks last week and asked them what the status was. Janet and Rosalie promised me that they would contact Fiber-Resin to get a final resolution on the matter. Less than two days later, Rosalie faxed me a copy of the following letter from Fiber-Resin, with a request that I post the letter to the group. Please forgive any spelling errors -- my fax isn't the greatest: Fiber-Resin Corp. 20701 Nordhalf St. Chatsworth, CA 94311 Rosalie Thiems Wicks Aircraft Supply Co. 410 Pine Street Highland, Illinois 62249 Fax: 618-654-6253 Dear Rosalie, It was a pleasure speaking with [you] regarding the FH2427 A&B resin system. The technical laboratory personnel at Fiber-Resin Corporation in Chatsworth, CA have investigated and reviewed the quality history of both the part A and the part B as well as specifically retesting our retain and stock of the FH2427B lot # CEHE066. All of the results and retesting confirm the original Q.C. test data indicating that the material is in specification. This supports your observations of your stock that the material is fine. I would like to reconfirm that in handling all resin systems, it is very important to keep the containers tightly sealed except when dispensing material. This helps to keep expose [sic] of the material to air, humidity and other possible contamination down to a minimum and maintain the product physical properties and storage life. The FH2427 resin system may be slightly more sensitive to air and/or humidity than other resin systems such as those that contain styrene and/or MDA. This is a trade-off for the significant safety and environmental advantages of the FH2427 resin system. One way to maximize the quality and storage life of FH2427 resin system and for that matter any resin system is to displace the air and humidity from the container headspace each time the container is closed using some form of dry gas such as nitrogen or FH8440 "Burp" available in aerosol cans. We periodically receive inquiries from users of FH2427 as well as users of other resin systems concerning a wet lay-up laminate not looking or curing correctly (too brittle or too soft), resin or hardener not looking right (cloudy, off color, etc.) or the resin not wetting out the fiberglass. In almost every situation the problem relates to techniques and procedures. Mix ratio of the part A and part B must be accurate. The resins and hardeners must be kept free of contaminants including air and humidity. The resins and hardeners should be used within the stated shelf life. The fiberglass or other fabric being used must also be kept free of contaminants including humidity and moisture. The application must be allowed to cure adequately to achieve the final physical properties. If we can be of further assistance regarding any of the Epolite products do not hesitate to contact our Customer Service Department. Thank you for your continued interest in Fiber-Resin products. Sincerely, (Signed) Randolph M. Olson Facility Manager So, while we didn't know it at the time, the mad scramble over the quality of lot CEHE066 turned out to be much ado about nothing. That's one of the disadvantages of electronic communications. Sometimes, we tend to transmit messages before we have the opportunity to check our facts. As builders of aircraft, we need to deal in facts, not opinions (unless clearly stated). Remember the old engineering addage: engage brain before mouth. We will never know why Neil's batch appeared cloudy. It may be that the can sat open for too long at Fiber-Resin before being sparged with dry nitrogen This is doubtful. When a company is in a production mode, things tend to get messed up in large quantities -- not just in a single can. As a Chemical Engineer myself, I can state that with the voice of experience. Then again, it may be that Neil had the can open for too long on his bench. This is also doubtful. That's not the way we tend to use the material. We generally just open the can and pour it into the pump's storage container. It may be that the can had an undetected pinhole leak or that the can was damaged in transit. This is possible, I suppose, althought I have never seen it actually happen. In any event, as Nat has taught us (and as Bill Kleb reminded us), **we** are the final quality control inspectors for all materials that go into the construction of our aircraft. If this event has taught us nothing else, it should remind us that **we** must verify the quality of all materials that we receive from our suppliers. Because of the volume of material that they receive, we cannot expect our suppliers to open every can of epoxy that appears on their shipping docks. That responsibility falls on us. I would like to comment that I feel that it is inappropriate for us to contact Wicks' suppliers for information regarding the quality of their products. If we have a problem with materials shipped to us, we should bring the matter up with Wicks (or to whomever we buy them from) and give them sufficient time to resolve the matter. No item is so critical in the construction of a homebuilt aircraft that it can't wait a few days for Wicks to resolve any perceived problems. If we decide to bypass the chain of command and go to one of Wicks suppliers, we can potentially hurt the relationship that Wicks has developed with its suppliers. In the extreme, a supplier might decide that doing business with Wicks isn't worth the trouble of having to field complaint calls from builders. Then, who would we have to deal with to get materials to finish our aircraft? It certainly isn't appropriate to announce that a problem exists before our suppliers have had a chance to check the facts. To do so hurts our suppliers. It may be appropriate to suggest to the group that a problem **may** exist and that you're in the process of trying to verify the problem with our suppliers but, if you decide to do this, make sure that you let the group know that the perceived problem is unconfirmed. I would like to thank Rosalie and Janet for their prompt and courteous attention to this matter. Those of us who have used the material can now rest assured that the epoxy is fine. I am, and always have been, delighted with the courtesy, speed and quality of service offered to me by Wicks. Their employees are knowledgeable, their computers can tell us the status of their stock while we are ordering, they are friendly and they bend over backwards to help us. They have earned our respect and we owe them our thanks. Jim Cullen Cozy Mk IV S/N 0076 (in the nest) Date: Wed, 05 Jun 1996 08:36:54 From: JRaerocad@gnn.com (Jeff Russell) Subject: COZY: COZY epoxy Colors of Resin systems Hexcel's RAE 2426 resin & 2176, 2177 hardeners (Red for fast, Blue for slow) Hexcel's EPOLITE 2410 resin & 2183, 2184, 2187 hardeners (Light to dark brown) Hexcel's EPOLITE 2318 resin & 2316 hardener (clear) Hexcel's 2427 resin & hardener (clear to light amber) CPD's replacement EZ24 resin & EZ83,84,87 hardeners (Dark yellow) Garfield asked >O.K. here are my questions: >1. If 2426 is the old RAE stuff, which is reported to be brownish >or bluish green (depending on hardener used?), if Wicks is going to >carry it again, who is the manufacturer now & is the color the same as >the old, (if not what is the distinctive color?). Jeff's post above >seems to suggest that the old RAE/2426 stuff WAS amine based; is the new >reissue of 2426 subject to amine humidity problems or not? Was the >old? 2426 will still have humidity problems >2. Which of the above systems mentioned by Jeff is the numbers for >what used to be SafeTPoxy I (and II)? And did the old SafeTPoxy I >contain Styrene & MDA? I thought SP II removed these components. SafeTPoxy I 2410/2183 or EZ10/EZ83 contain Styrene & MDA SafeTPoxy II 2410/2184 or EZ10/EZ84 contain Styrene & MDA AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Wed, 05 Jun 1996 10:22:55 +0000 From: Eric Westland Subject: Re: COZY: BURP & Dry Nitrogen I pour the entire can into my pump and have been using Phillip's excellent idea of placing a plastic bag in the top of my hardener pump container so that as the hardener empties, the bag fills the space. It's free and works well (although I have not had any 2427 problems in my climate). I see no reason why you could not just inflate a bag in the can to push out the air. -eric michael (m.j.) anderson wrote: > > I had sent an earlier email asking about MEK and BURP/dry nitrogen. > I got plenty of opinions on MEK, but nothing on the BURP or dry > nitrogen to sparge my resign and hardner cans. Does anyone do this? > I currently keep the cans in the house, for climate control, but I > would like to sparge the air/humidity out of them. > > Please let me know where do you get BURP and/or the dry nitrogen. > > Thanks, > > Michael Anderson > mikej@nortel.com > Cozy Mark IV #484 by mta bnr.ca in /PRMD=BNR/ADMD=TELECOM.CANADA/C=CA/; Relayed; Wed, 5 Jun 1996 10:53:47 -0400 by /PRMD=BNR/ADMD=TELECOM.CANADA/C=CA/; Relayed; Wed, 5 Jun 1996 10:53:27 -0400 by /PRMD=BNR/ADMD=TELECOM.CANADA/C=CA/; Relayed; Wed, 5 Jun 1996 10:53:00 -0400 Date: Wed, 5 Jun 1996 10:53:00 -0400 [/PRMD=BNR/ADMD=TELECOM.CANADA/C=CA/;bcars735.b.952:05.05.96.14.53.27] From: "michael (m.j.) anderson" Subject: COZY: BURP & Dry Nitrogen I had sent an earlier email asking about MEK and BURP/dry nitrogen. I got plenty of opinions on MEK, but nothing on the BURP or dry nitrogen to sparge my resign and hardner cans. Does anyone do this? I currently keep the cans in the house, for climate control, but I would like to sparge the air/humidity out of them. Please let me know where do you get BURP and/or the dry nitrogen. Thanks, Michael Anderson mikej@nortel.com Cozy Mark IV #484 Date: Wed, 5 Jun 1996 23:59:04 -0400 (EDT) From: Bill Walsh Subject: Re: COZY: New EZ epoxy Iwill let Jeff answer the detail questions (he has more time and is more knowlegable) But seeing as my name is attached to this questionI will give only one observation.....COLOR....Imay be mistaken but I don't think that it would ba an accurate gauge. Some of my batches were considerably lighter than others and the new stuff that is being promoted is practically clear, RAE is dark, But as mine has cured it too has gotten very dark in color. And if you were referring to a possible purchase where you check the coloring of the cured parts,you would have to go to a part that hadn't been filled or painted. Don't think this matters much as a gauge for quality or strength. Thought I'd throw in 2 bits Bill W Date: Sun, 07 Jul 1996 23:19:24 -0400 From: Jim Hocut Subject: COZY: More Epoxy Woes After reading the information presented here and in the Central States newsletter about problems associated with using Hexcel 2427 in high humidity conditions I decided to take heed and switch to Safe-T-Poxy II for the time being. I'd previously done all my work in my air-conditioned shop and had no problem whatsoever with 2427, but for a while I'm going to have to rough it and work without air conditioning. I was at Aircraft Spruce East the other day to pick up some Safe-T-Poxy, and was told that the firm that bought out Hexcel's epoxy business had no interest in the homebuilt airplane market (let me guess, liability concerns?) and that production of all of the epoxies we have grown to know and love has ceased (including 2427, so the humidity concern will soon become a moot point). When I asked about Gordon Bowens' EZ-Poxy I was told that they had hardener in the warehouse, but no resin yet. Not wanting to go home empty handed, I asked for a suggestion, and was told that quite a few homebuilders were using Poly Poxy. I went ahead and bought some, figuring I'd use it for the time being on non structural layups and see what I think of it. 1) Does anyone have experience with Poly Poxy, good or bad? It claims to be a 2 phase system, so it has the potential of being pretty good stuff if their claims are true. 2) Is anyone shipping EZ Poxy yet? (Jeff Russell had offered earlier to sell us EZ Poxy from his stock - is that offer still good, and what's the co$t and delivery time?) Thanks, Jim Hocut jhocut@mindspring.com Date: Mon, 08 Jul 1996 12:52:17 From: JRaerocad@gnn.com (Jeff Russell) Subject: COZY: Epoxys Jim Hocut wrote: >1) Does anyone have experience with Poly Poxy, good or bad? It >claims to be a 2 phase system, so it has the potential of being >retty good stuff if their claims are true. We have used it quite a few times. It will also pick up some water. It is a good resin system as we have never seen any problems with the water except blush. You must remove any blush before the next layup. It also changes color when it reaches it's 2nd phase (milky white). >2) Is anyone shipping EZ Poxy yet? (Jeff Russell had offered >earlier to sell us EZ Poxy from his stock - is that offer still >good, and what's the co$t and delivery time?) It's in, and I have not been billed yet. I am looking into cans and labels but pricing should be around $65.00 for 8 lbs resin and 3.5 lbs hardener EZ10/EZ84 Gal kit AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Mon, 8 Jul 1996 09:30:13 -0400 From: william l kleb Subject: COZY: safe-t-poxy availability FYI: aircraft spruce west is carrying and has the safety-poxy clone in stock. bil Date: Mon, 08 Jul 1996 10:02:12 -0500 From: Neil Clayton Subject: COZY: 2427 and Humidity Since Nat's reference in his latest newsletter to my problem with 2427 and "humidity", the subject seems to have become settled by hearsay. I had the "bad" batch of 2427 that contained cloudy floating globs of higher viscosity than the general fluid. On the advice of a Hexcel chemist, I didn't use it, and Wicks replaced it. But...I noticed it immediately on opening the can. It wasn't exposed to Florida's humidity more than a few seconds, and then only the exposed surface area. I don't buy the 2427-humidity theory. The chemist told me the can probably wasn't topped off with inert gas in the factory. Later can's I've received also have traces of the cloudiness, but not anything like as bad. Neil From: garfield@pilgrimhouse.com (Garfield) Subject: COZY: 2427 and Humidity Date: Mon, 08 Jul 1996 17:46:15 GMT On Mon, 08 Jul 1996 10:02:12 -0500, Neil Clayton wrote: >Since Nat's reference in his latest newsletter to my problem with 2427 >and "humidity", the subject seems to have become settled by hearsay. ^^^^^^^^^^^^^^^^^^^ Whoa, wait a minute. Nat's a great guy, but I think he is the one operating on hearsay on this one. The problem is very real. I have seen it and touched it with my own eyes and hands. Nat is in Arizona. He will likely never see the problem. >But...I noticed it immediately on opening the can. It wasn't exposed to >Florida's humidity more than a few seconds, and then only the exposed >surface area. I don't buy the 2427-humidity theory. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Why do you think the chemist at the factory advised you to inert-gas burp the can whenever you closed it? Also, I remember seeing a response letter, which said they suspected that a particular lot of cans was made without filling the void with inert gas. In the case of your cloudy can, the exposure likely happened BEFORE you opened it, if the can had sat with air in the void for some time. Finally, it's not just humidity, but any oxidizing atmosphere, namely a place like California that has a lot of smog, with lots of CO, NO, ozone, and such. I was doing a wing layup in LA (world-class smog capital) California the first time I tried some 2427. It came from a can directly off the shelf of Aircraft Spruce West. I talked to Jeff Russell/Aerocad who said he had the same milky white sticky surface develop on some of his parts (N/S Carolina), and finally had to stop using 2427. These experiences should not be dismissed as mere hearsay. Rumors are a wretched thing, but this is not just a rumor. Over time the resin/hardener can be absorbing the atmospheric contaminants, and then when it really gets exposed while it is being mixed and then gets it's last grand dose when you layup the part and the wet surface sits out in the air for 4 hrs, the sticky blush may appear. When the problem appears, the surface remains tacky even several hours after the epoxy has had time to cure, so it's not some boogie-man that is going to bite you unawares, but there WAS a recent report on the net about someone discovering delam when a 2427 part was torn apart. I can only surmise that IF it was due to this "amine blush" problem, the person wasn't being very aware of the surface quality when subsequent laminations were layed up. The only way this can happen is if you 1) didn't peel-ply OR 2) didn't sand between cured layups. Whoever is building this way is asking for delams anyway. So anyone with any experience that has existing 2427 parts shouldn't be worrying, I would think. Just something to watch for if you continue to use it. And if you do get a surface that resembles this amine blush, you can confirm it by trying to remove the stuff with water. If it's poorly cured epoxy, it won't be water-soluble. The amine blush is. Garfield Date: Mon, 08 Jul 1996 19:06:06 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: COZY: 2427 and Humidity Garfield wrote: >but there WAS a recent report on the net about someone discovering >delam when a 2427 part was torn apart. I can only surmise that IF >it was due to this "amine blush" problem, the person wasn't being >very aware of the surface quality when subsequent laminations were >layed up. The only way this can happen is if you 1)didn't peel-ply >OR 2) didn't sand between cured layups. We had a case on the BerKut we were building, tape glassing on a peel plied firewall to peel-plied fuselage tub and they were sanded with 36 grit completely dull. It was in Oct. and about 65 - 70 degrees in the shop and about 80-90% humid. The 2427 was in an epoxy pump and the hardener was just starting to turn a little cloudy. A year had past and Dave Ronenberg cam to our shop to help on this airplane and tried to peel off some of the tape glass were the main spar went and it peeled off like it was on wax paper. You could see the sanding job next to the tape glass were it had not seen any new epoxy. We both scratched our head. Water in the pump? water in the glass? water as it cures? don't know, but that was the last time I used it on structural parts. A builder 20 miles from me that was using RAE and switched to 2427 was also checked for this kind of problem and guess what??? Same thing but he was not using a pump. He switch to 2410/2184 and that was the end of that. Winter was also a factor here. For us to be on the safe side, that is the only resin that I use for structural parts and airplanes. AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Tue, 9 Jul 1996 17:35:58 -0400 From: Marcnadine@aol.com Subject: 2427 Well, now after hearing all the horror stories about 2427 epoxy, does anyone want to buy a complete fuselage, canard, and main spar for $1.00 built with 100% 2427 ? Any offers? Marc Parmelee N425CZ Date: Tue, 09 Jul 1996 19:36:57 -0700 From: Mark Morris Subject: COZY: Epoxy Toxicity & Postcure 1. Are the users of MDA containing epoxies greatly concerned about the MDA risk? Is ply 9 reasonably acceptable or is everyone using multiple layers of gloves and respirators? 2. Will a cured 2427 part bond to another part acceptably using RAE or Safety-Poxy I/II? Is there any degradation caused by mixing epoxy systems? 3. I went in to this thinking postcure was an option ... but a review of this years archive of messages has me concerned. I noticed a comment that all "structural" components should be post-cured (I forget who said it). Other than the arm rests and a few such items, what isn't "structural?" Will a white aircraft in Florida need to be postcured? Mark Morris (new here; just completed CH 4.) From: Marc J. Zeitlin Subject: COZY: 2427 (fwd) Date: Wed, 10 Jul 96 8:49:07 EDT Marc Parmelee wrote: >Well, now after hearing all the horror stories about 2427 epoxy, does anyone >want to buy a complete fuselage, canard, and main spar for $1.00 built with >100% 2427 ? Well, Marc, I sure hope this is a joke. I've built 100% of my plane with 2427 also, and while I've certainly had my share of problems learning how to deal with it and have had to do a few layups over, it wouldn't even OCCUR to me to dump it. I have complete confidence that the aircraft will be structurally sound, as I make sure that I perform all my layups so that the epoxy will bond. Again, I hope you're joking. If not, I might take you up on the canard :-). Might even give you $5.00 . -- Marc J. Zeitlin Email: marcz@an.hp.com From: Marc J. Zeitlin Subject: COZY: Epoxy Toxicity & Postcure (fwd) Date: Wed, 10 Jul 96 9:01:13 EDT Mark Morris writes: >1. Are the users of MDA containing epoxies greatly concerned about the >MDA risk? Is ply 9 reasonably acceptable or is everyone using multiple >layers of gloves and respirators? Use gloves and respirators - I can't emphasize this enough. I used ply 9 (or the equivalent) for the first two years of building my Q2. I became allergic to the Safety-Poxy on my fingertips. I've been using gloves for 1-1/2 years now, and the only time I have an allergic reaction (and it's a doozy) is when I accidentally drip epoxy on my forearms during a layup and don't stop to immediately wash it off. The gloves (butyl) will protect your hands from EVERYTHING, MDA included. The carbon filter mask will protect your insides from everything. The gel will not do either. Don't take any chances - you can build perfectly well with a mask and gloves on. >2. Will a cured 2427 part bond to another part acceptably using RAE or >Safety-Poxy I/II? See below - should be "yes". >............. Is there any degradation caused by mixing epoxy >systems? Someone correct me if I'm wrong, but once the epoxy has cured, any bond to it is a structural, not chemical one. If the cured epoxy is sanded, the next epoxy should bond OK. Therefore, the answer to your question should be "no". >3. I went in to this thinking postcure was an option ... but a review of >this years archive of messages has me concerned. I noticed a comment >that all "structural" components should be post-cured (I forget who >said it). Other than the arm rests and a few such items, what isn't >"structural?" Will a white aircraft in Florida need to be postcured? While most everything is "structural", not everything is highly stressed. Definitely post-cure the wings, main spar and canard. -- Marc J. Zeitlin Email: marcz@an.hp.com From: George Graham Subject: COZY: 2427 epoxy Date: Thu, 11 Jul 1996 03:23:14 GMT Organization: AirSep Corporation Myself and many other builders, are very upset (worried ?) about the quality of this epoxy, since Jeff Russell blasted it. The day after the last Central States newsletter, I was pulling and banging away at my latest taped joints. They all appear to be as sound as any other epoxy layups. Pulled the wood off the wood parts, took pliers to start delamination on one day old layups done while it was raining outside. I wonder what gives ? Gorden Bowen, Nat Puffer, Mike Melville, Burt Rutan etc. would somebody please tell us if this stuff is garbage or not ! George Graham Modified E-Racer #206 From: RJMANC@cris.com Date: Fri, 12 Jul 1996 01:07:35 -0400 (EDT) Subject: COZY: 2427 I don't know whats up with 2427 !!! I live in a warm dry climate and have had no problems so far !! I put 2427 in my pump over a month before I used it ... (didn't do this on purpose but had some emergencies and couldn't start my layups) And I see no cloudiness or have I experienced any problems with layups.. I have my pump in a heated box to keep it at a steady tempature.. I have buit 3 of the bulkheads and numerous test projects and have noticed no problem.. I am concerned our winters are very wet and sometimes a little humid... I'm no expert but don't want to spend countless hours and dollars just to go to waste.. I would like to hear more about this any input.. My 2 cents Robert Mancuso Los Banos Ca (209)826-6814 Chapter 4 00 \______O00O0______/ | | | O 0 O #537 Date: Sat, 13 Jul 1996 03:18:52 GMT From: Neil Clayton Subject: COZY: 2427 curing I was skinning a wing the other night (great weather, no humidity) but as I put the first layer of uni on, I noticed the pump *seemed* to be putting out less than the usual stream of hardener. Thinking it was my imagination, I kept working but still had the same bad feeling about the goop the pump was putting out. The colour was wrong (or was it?) Dreading having to undo all my work if the ratio was wrong, I peel plied what I'd done and turned my attention to the pump. I took the hardener side apart and cleaned everything. I saw no blockages and nothing to cause a slower-than-usual flow. A few days later, I removed the peelply and it looks like a "normal" layup. Is it OK to just sand the surface down and do the final layers? I hate having a surface to surface joint in such a critical piece. What's the criticality of the ratio? Does it need to be exactly 44:100? Will a few percent either way effect it? And finally, is there any test I can do to check the quality of the layup? (Like the Rockwell hardness test?) Or is the only test the "keep me aloft at 10,000 feet" test? I like working with 2427, and I like the nice cosmetic finish it leaves, but I'm starting to have some serious credibility problems with it. Neil Date: Sun, 14 Jul 1996 22:18:47 -0400 From: Jim Hocut Subject: Re: COZY: 2427 curing Neil Clayton, wrote: > What's the >criticality of the ratio? Does it need to be exactly 44:100? Will a few >percent either way effect it? And finally, is there any test I can do to >check the quality of the layup? In a forum at Oshkosh last year (maybe the year before?) (seems like it was Martin Holliman's forum) it was stated that epoxy ratio is quite critical, you want to be within better than 5%. It was also stated that a good test of your epoxy is to occasionally pour some epoxy into a plastic cup and let it cure. After full cure you should be able to scratch the surface with a nail and leave behind a trace of dry residue. If the ratio is off the epoxy will be soft enough that no powder will come off when you scratch it. This very problem is why I chose not to use a pump, I purchased the postal scale from Alexander and keep different colored bicycle water bottles filled with resin and hardener. I printed a listing of resin and hardener weights for different size batches and stuck it to the wall behind where the scale resides - very quick and extremely consistent batches. Jim Hocut jhocut@mindspring.com From: "Steve Campbell" Subject: COZY: 2427 Epoxy Date: Mon, 15 Jul 1996 11:24:11 Marc J. Zeitlin writes: >It seems as though the 2427 is more sensitive to humidity, temperature, >time between layups and surface preparation than other epoxies might be. >While I have some concern with using it, I have not had any experience >that would show that ___IN MY WORKSHOP___ (Your Mileage May Vary) I >should use something else. I watch the temperature, peel ply >religiously, sand vigorously, and everything seems OK. Let me agree with what Marc says here. I am also using 2427 in my basement and had the unfortunate experience of having to remove my longerons in Chapter 5 as I had mounted them backwards and didn't discover it until the sides were completely glassed. The the glass was a real ***** to get off except in one area where it came off easily. I later realized that I had forgotten to sand and/or peel ply that area. I do both now religiously and vigorously as Marc so aptly put it. Steve Chapter 10 in progress **************************************** Stephen A. Campbell Associate Professor, EE University of Minnesota ***************************************** From: Marc J. Zeitlin Subject: Re: COZY: 2427 curing (fwd) Date: Mon, 15 Jul 96 9:08:05 EDT Jim Hocut wrote: >In a forum at Oshkosh last year (maybe the year before?) (seems like it was >Martin Holliman's forum) it was stated that epoxy ratio is quite critical, >you want to be within better than 5%. It was also stated that a good test >of your epoxy is to occasionally pour some epoxy into a plastic cup and let >it cure. After full cure you should be able to scratch the surface with a >nail and leave behind a trace of dry residue. If the ratio is off the epoxy >will be soft enough that no powder will come off when you scratch it. I had heard this same test. I have been conducting some no-so-scientific tests of the 2427 for the past few weeks, while cleaning out my pump and doing layups. Every once in a while, I'll put some resin and hardener in a cup and mix them up (knowing that the ratio isn't 44:100 - but I didn't weigh them so I don't know what it IS). No matter the ratio - too much hardener or too little - the 2427 has ALWAYS cured, and always passed the scratch test. Don't know what this proves, if anything, but it seems to be less sensitive to ratio than the directions would claim. My pump certainly puts out a ratio that cures perfectly well. WRT Neil's other question, if the surface you're concerned about sands well (basically the scratch test on a large scale) and was peel plied, then subsequent layups should adhere just fine. It seems as though the 2427 is more sensitive to humidity, temperature, time between layups and surface preparation than other epoxies might be. While I have some concern with using it, I have not had any experience that would show that ___IN MY WORKSHOP___ (Your Mileage May Vary) I should use something else. I watch the temperature, peel ply religiously, sand vigorously, and everything seems OK. -- Marc J. Zeitlin Email: marcz@an.hp.com From: ratencio@coastalnet.com Date: Wed, 17 Jul 96 08:57:26 -0400 Subject: COZY: Epoxy pumps & 2427 After reading the msg traffic on 2427 epoxy, I was a little concerned since I had used 2427 for my chpt 4 layups and had just made the upper longerons using this stuff. I did some quick comparison testing (very unscientific) and thought I'd post my findings. I decided to go do the scratch test on some left over resin from my previous epoxy work and it passed. This stuff was at a 44:100 ratio by volume. (oops!) I readjusted the pump for a 47:100 ratio and made a small batch which too passed the scratch test. Someone stated earlier that mix ratio of 2427, or epoxy resins in general, should be within 5 percent. A 44:100 ratio is a little over 6 percent on the low side. I think Marc Z. mentioned he thought 2427 was less sensitive to mix ratio than humidity. I have to concur with this statement, except that I have not seen any humidity effects on any of my layups. Here in eastern NC the humidity is typically very high, 90 percent. Maybe I've just been lucky. Either way, I plan on continuing to use the 2427 epoxy. My 2 cents ----------------------------------------------------------- Rob Atencio Cozy Mk IV #496 Chp 5 New Bern, NC E-Mail: ratencio@coastalnet.com ----------------------------------------------------------- Date: Sat, 20 Jul 1996 23:30:13 -0400 From: StetsonE@aol.com Subject: Fwd: COZY: My Peel-ply lesson (fwd) In a message dated 96-07-17 11:06:26 EDT, marcz@hpwarhw.an.hp.com (Marc J. Zeitlin) writes: > The 2427 will NOT bond > to itself if it has started to kick (cure). The lesson here is (as Rob > says) to peel ply early, and stop a layup if the epoxy has begun to cure. > I now schedule layups this way, and everything has been fine since. I talked to a Cozy builder awhile back who said they were using 2427 when glassing the inside of the top strake covers. The layup had started to kick, but they floxed it into place on the plane anyway (their first mistake). After a full cure, they were anxious to to see if they had any leaks, so they did a pressure test of the tank before they glassed the outside of the strakes (their second mistake). They basically blew the top of the tank off..... Of course, the flox didn't bond to the interior layup of the tank top. After hearing this, I applied suction, not pressure, to my fuel tanks when checking for leaks, although Long-EZ plans say you can use either. 2427 epoxy must be funny stuff. I've never had debonding problems with Safe-T-Poxy, which is all I've used. It bonds well as long as the underlying layup is a little "green". Thankfully, my structure is done so I don't have to worry about the epoxy issue. Stet Elliott stetsone@aol.com Perpetual Long-EZ builder --------------------- Forwarded message: From: marcz@hpwarhw.an.hp.com (Marc J. Zeitlin) Sender: owner-cozy_builders@hpwarhw.an.hp.com Reply-to: marcz@hpwarhw.an.hp.com (Marc J. Zeitlin) To: cozy_builders@hpwarhw.an.hp.com (Cozy MK-IV Builders) Date: 96-07-17 11:06:26 EDT Rob Atencio wrote: After sanding ALL the peel-plied areas, I feel confident I have good >bonding surfaces, which I wouldn't have had with the poor peel-ply job I >had done. This took more time to ensure all the loose epoxy was removed >but I did learn something in the process. I had exactly this same thing happen on my canard shear web layup. I don't think it's the peel ply's fault - we're both using 2427, and as you said, it happened on the areas we laid up FIRST. The 2427 will NOT bond to itself if it has started to kick (cure). The lesson here is (as Rob says) to peel ply early, and stop a layup if the epoxy has begun to cure. I now schedule layups this way, and everything has been fine since. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Tue, 6 Aug 1996 17:12:29 -0700 From: Sam Pavel Subject: COZY: Epoxy Greetings all, After an inspiring sojourn to OSH I am ready to jump in with all four feet. However, I have a question about the effect of epoxy resins and hardeners on plastic and rubber. To make a short problem entirely too long, I have discovered a method of measurement that is very accurate and easy. My wife (a medical lab tech) gave me these rather large syringes. I will use one for the resin and one for the hardener. Then I started wondering if there might be an adverse chemical reaction with the materials in the syringes and the materials in the epoxy. My limited knowledge in chemical reactions is no help in this problem. Thus I turn to others to garner some advice. Does my idea have merit, or am I working toward some unwanted chemical metamorphosis? Thanks in advance, Sam Sam Pavel 53230 Oakton Drive MkIV #544 South Bend, IN 46635 Have plans and built table.... (219)273-0321 email: pavel@nd.edu Date: Tue, 6 Aug 1996 21:23:28 -0400 From: SMilesCozy@aol.com Subject: Re: COZY: Epoxy Sam Pavel writes: >After an inspiring sojourn to OSH I am ready to jump in with all four feet. (snip) > My wife (a medical lab tech) gave me these rather large syringes. I will use one >for the resin and one for the hardener. (snip) > Does my idea have merit, or am I working toward some unwanted chemical >metamorphosis? The fiberglass technical counselor for our chapter, EAA 32, used this method for his lanceair 320 and the composite workshop he ran for our chapter. It looks pretty slick, although I prefer to weigh my fabric and mix my epoxy for a 50-50 epoxy to cloth ratio. I learned this at an Alexander workshop when Stan Montgomery was instructing, and it seems pretty efficient, although vacuum bagging would be better. If they're cheap, fill a couple of them up with resin and hardner and let them sit for a couple of weeks, should identify any chemical breakdowns by turning to goo :^) Good luck, Steve Miles Cozy MkIV 272 From: Marc J. Zeitlin Subject: COZY: Epoxy Allergies Date: Wed, 7 Aug 96 13:24:33 EDT People; One of the mailing list members unsubscribed recently, and I thought that I'd post the reason why for those of you who are a bit lackadaisical in your "safe epoxying" practices. >... I've been battling an allergy to epoxy for the last 4 months, and my >body has finally said no way. I've gotten to the point where just the fumes >were causing a rash (and blisters) on pretty much anything that wasn't >covered in vinyl or the fresh air breather mask. I even tried having a fan >behind me all the time and still had problems. I've been taking antihistamines >to counter the effects of the epoxy, coffee to counter the effects of the >antihistamines, and blood pressure medicine to counter the effects of both. >In short my doctor told me I was killing myself. My wife told me she would >rather live without a plane than a husband. I decided that somewhere in >chapter 10 just wasn't far enough to have someone else finish off the plane. >But you were probably just looking for the short answer. > >Thanks for all your help. The mailing list is great. This was the hardest >decision I've ever had to make even though it was pretty much made for me. Please, protect yourselves. These reactions may not show up for years (it took 2 years for me to show allergic reactions), so the fact that you haven't had any reaction _yet_ is not an indication that you won't. -- Marc J. Zeitlin Email: marcz@an.hp.com From: "Volk, Ray" Subject: Re : COZY: Epoxy Allergies Date: Thu, 8 Aug 1996 10:14:00 -0400 Marc write; >>I thought that I'd post the reason why for those of you who are a bit lackadaisical in your "safe epoxying" practices. Thanks for posting this Marc, I too had a real serious attack 6 months into my project but feel I have it under control now, 8 months later. People need to realize it's probably not "if" its "when". >I've gotten to the point where just the fumes were causing a rash (and blisters) on pretty much anything >that wasn't covered in vinyl or the fresh air breather mask. This person must have had it at least as bad or worse than I. A long sleeve shirt was not sufficient protection for me ether, I have to wrap my arms with plastic over the long sleeve shirt. I think I have previously posted what I do for protection and I now have no problems at all although at the time I had 2 months of real pain and was facing giving up the project myself. If anyone is struggling with this problem and uncertain what to do, they can contact me ether in this form or "off line" and I will be glad share my experience, i.e. what works and what doesn't. Ray Volk #426 Completed chapters 4-7, 10,11,14,19 and into 20. email rvolk@space.honeywell.com Date: Tue, 13 Aug 1996 00:02:42 -0400 From: Jim Hocut Subject: COZY: Epoxy Allergies I know we've discussed this subject to some extent in the not too distant past, but I've got a couple of questions that I don't beleive have been asked and may be of interest to more people than just myself. a) Are there any warning signs before a full blown allergy sets in? Itching after working with the offending epoxy, irration of the eyes, etc.? b) Is it the resin or hardener that causes the problem? I'd guess it's the hardener, but haven't heard a definitive answer. c) If someone develops an allergy to a particular epoxy (2427 for instance), could they switch to another system (say "Saf-T-Poxy") with little or no reaction (and take greater precautions the second time around)? Also, just a thought for someone who may be unable to work with epoxy because of allergies. I realize it's a long shot to make this work out, but in a case or two there may be another builder willing to go along. Maybe, just maybe, someone might be lucky enogh to find another builder (maybe even someone building something other than a Cozy) who's proficient at fiberglass, lives nearby, and would be willing to trade off hours spent doing layups for hours spent cutting foam, preparing for layups, SANDING, etc. (in other words anything that doesn't involve exposure to uncured resin). My 2 cents worth. Jim Hocut jhocut@mindspring.com From: Marc J. Zeitlin Subject: COZY: Epoxy Allergies (fwd) Date: Tue, 13 Aug 96 10:25:29 EDT Jim Hocut asks: >a) Are there any warning signs before a full blown allergy sets in? >Itching after working with the offending epoxy, irration of the eyes, etc.? I didn't have any reaction at all with the Safety-Poxy 14 years ago until one day - BANG!!! - my fingers swelled up and itched like mad. Others may have different stories. >b) Is it the resin or hardener that causes the problem? I'd guess it's the >hardener, but haven't heard a definitive answer. Hardener. That's got the nasties in it. >c) If someone develops an allergy to a particular epoxy (2427 for instance), >could they switch to another system (say "Saf-T-Poxy") with little or no >reaction (and take greater precautions the second time around)? I doubt it. I waited 14 years, and switched from SP to 2427 (not a huge difference, to be sure) and IMMEDIATELY had a reaction when I accidentally got some epoxy on my forearm below the gloves. Most of these laminating resins are pretty similar, so I'd bet that if you get a reaction to one, you'd have a reaction to another. Once again, gloves, long sleeves, no skin contact and masks are the requirements. -- Marc J. Zeitlin Email: marcz@an.hp.com From: stan magill Subject: COZY: Allergies to Epozy Date: Tue, 13 Aug 1996 15:54:35 +0000 Response to allergy problems with expoy systems. I had a severe reaction to Safe-T-Poxy which forced me to stop my project. I then switched to the RAE system and had no reaction at all. When RAE was not avaliable, I switched to Aeropoxy from PTM&W and still have no reaction. Your body may not be sensitive to all epoxy systems and therefore you will be able to complete your dream machine. Stan Magill SMJW@Worldnet.att.net From: stan magill Subject: COZY: Allergies to Epozy Date: Wed, 14 Aug 1996 14:59:43 +0000 Response to allergy problems with expoy systems. I had a severe reaction to Safe-T-Poxy which forced me to stop my project. I then switched to the RAE system and had no reaction at all. When RAE was not avaliable, I switched to Aeropoxy from PTM&W and still have no reaction. Your body may not be sensitive to all epoxy systems and therefore you will be able to complete your dream machine. Stan Magill SMJW@Worldnet.att.net Date: Wed, 14 Aug 1996 20:30:07 -0400 From: Jim Hocut Subject: Re: COZY: Epoxy Allergies Mark Morris wrote: > ... But I really don't believe all builders are going to these >lengths to protect themselves. Quite frankly I'm not sure I could put >in 3000 hrs dressed in armor :>). What do you think? > A friend from my EAA chapter has been using "Saf-T-Poxy" for about 2 years with disposable latex gloves, and being careful not to get it on his skin. No special ventillation precautions, and no problems so far. As for myself, I've been using 2427 (extremely low odor) for a year with the same precautions and no problems. I've also just started using Poly Epoxy, which has more odor (and therefore more organics which I will breath), and Marc's statements have scared me into at least trying out a respirator with activated carbon cartridges. So far so good. I know some medical type will probably shoot my theory all to hell, but I'm not allergic to ANYTHING (that I know about), even sat in a poison ivy patch as a kid with no ill effect, so I suspect that I have less of a chance of developing a reaction than someone who is more prone to allergies. Jim Hocut jhocut@mindspring.com Date: Thu, 15 Aug 1996 08:43:20 -0400 From: wilhelmson@scra.org Subject: Re[2]: COZY: Epoxy Allergies JIM: It is a documented medical fact(from my own and many others experience) that EPOXY allergies occur after extended exposure. It is almost like AIDS. BE CAREFUL. Date: Thu, 15 Aug 1996 09:27:00 -0400 From: william l kleb Organization: NASA Langley Research Center Subject: Re: COZY: Epoxy Allergies Jim Hocut wrote: > > So far so good. those always seem to be dangerous words as far as allergies are concerned... i think it has been mentioned before, but if you get a chance, watch the pbs show, nova, on allergies, it'll scare you into being much more cautious (that is if you want to continue building a composite plane). if nova does indeed contain unbaised science, then take heed: allergies are acquired though repeated exposure and it is only a question of when you'll have a reaction. this is the reason many people "become" allergic to more and more things as they grow older---they finally reach their tolerance for one allergen or another. > ... but I'm > not allergic to ANYTHING (that I know about), even sat > in a poison ivy patch as a kid with no ill effect. i am in the same situation, but i still wear cotton glove liners, two sets of gloves (nitrile or butyl and latex), a respirator, and a tyvex suit. i have dreamed of building a composite plane for the past ten years... WHY CHANCE IT? ---it is relatively easy to take precautions and far less expensive (both in terms of time, medical bills, and psychiatric bills ;) ) than the possible consequences. --- bill kleb (w.l.kleb@larc.nasa.gov) 72 bellanca 7gcbc 9! cz4 -> aerocanard From: Lee Devlin Subject: Re: COZY: Epoxy Pump and Epolite 2427/8 Resin Date: Thu, 15 Aug 1996 18:20:33 MDT > I have used the Ply #9 gel to protect me from the epoxy, I apply it well > up my forearms to protect the more delicate skin. As a dentist, I avoid the > use of latex gloves at home. If I develop an allergy to the gloves, then I > would have a big hassle at my office where I must wear gloves. Another option > is to apply Ply#9 gel beforeputting on gloves. I have found Ply9/disposable gloves to be ineffective in preventing me from getting a reaction to the epoxy. I am also one of those lucky individuals who had never in my life had an allergic reaction to anything. However, after about 4 months of building my plane, I got a reaction to the epoxy that came on just like flipping a light switch. My fingers swelled, turned red, and had a numbness and tingling feeling that lasted 2 weeks. The next time I made sure to use cotton liners along with the Ply9 and latex gloves, reasoning that my perspiration was disolving the water soluable Ply9 and rendering it ineffective. I got exactly the same reaction that took another 2 weeks to heal. Then I switched to butyl gloves along with disposable latex (or vinyl) over them. They have lasted for more that a year and I haven't had a reaction since I began using them. One night I needed to mix up a little flox to do a 5 minute job and reasoned that I would avoid getting any epoxy on my fingers so I just donned the vinyl gloves. To my amazement, I got a reaction even with this minimal amount of contact to the epoxy. To those graduates who have just tuned in, I have one word of advice: Butyl. Lee Devlin Date: Sat, 17 Aug 1996 13:54:56 -0400 (EDT) From: Tech Support - Rick Subject: Re: COZY: Epoxy Pump and Epolite 2427/8 Resin I had a reaction when I used ply9 and the latex gloves. However, when I switched back to straight latex gloves, or just ply9, no reaction. Proof? I had the reaction two weeks before sun 'n fun '95. I helped build four wings at sun 'n fun. Ask Jeff, he saw me there. No reaction. Even Burt cautioned against the combo of ply9 and latex. I understand why now! Rick Date: Sat, 17 Aug 1996 18:53:14 -0400 From: Jim Hocut Subject: Re: COZY: Epoxy Allergies Stet Elliot wrote: > ..... Rutan Aircraft >Factory reported in their newsletter some years ago that a few builders who >developed an allergic reaction to Safe-T-Poxy had good results by changing to >the older RAE epoxy system. It's interesting to note that the RAE was >considered at the time to be much more toxic than Safe-T-Poxy. Go figure. > I found out at OSH how Saf-T-Poxy came up with it's name (I'm thinking it was one of Burt's formus but can't recall for sure). At the time, they tested toxicity by shaving a patch of a rabbit's fur and applying an amount of the material being tested to the bare skin. A material was given a rating by how much of a reaction the rabbit's skin had. Well, they tested Saf-T-Poxy RESIN, which showed little or no reaction, hence the name. THE REST OF THE STORY is that Saf-T-Poxy HARDENER gave the bunny one hell of a rash, but nobody bothered to tell us poor builders what a nasty material it was. Also, in response to a question as to what precautions are being taken when using epoxy, I had mentioned that I was using latex gloves w/o a liner or butyl gloves etc. I neglected to mention that I change latex gloves often, I'll go through 5 or 6 pair in the course of a large layup. Again, this may not be quite as good as the other precautions, but it definitely reduces the possibility of nasty stuff getting through the latex and onto my skin. Jim Hocut jhocut@mindspring.com Date: Sat, 17 Aug 1996 20:33:31 -0700 From: "Steven D. Sharp" Subject: Re: COZY: Epoxy Allergies Jim Hocut wrote: > > Stet Elliot wrote: > > ..... Rutan Aircraft > >Factory reported in their newsletter some years ago that a few builders who > >developed an allergic reaction to Safe-T-Poxy had good results by changing to > >the older RAE epoxy system. It's interesting to note that the RAE was > >considered at the time to be much more toxic than Safe-T-Poxy. Go figure. > > > > I found out at OSH how Saf-T-Poxy came up with it's name (I'm thinking it > was one of Burt's formus but can't recall for sure). At the time, they > tested toxicity by shaving a patch of a rabbit's fur and applying an amount > of the material being tested to the bare skin. A material was given a > rating by how much of a reaction the rabbit's skin had. Well, they tested > Saf-T-Poxy RESIN, which showed little or no reaction, hence the name. THE > REST OF THE STORY is that Saf-T-Poxy HARDENER gave the bunny one hell of a > rash, but nobody bothered to tell us poor builders what a nasty material it was. > > Also, in response to a question as to what precautions are being taken when > using epoxy, I had mentioned that I was using latex gloves w/o a liner or > butyl gloves etc. I neglected to mention that I change latex gloves often, > I'll go through 5 or 6 pair in the course of a large layup. Again, this may > not be quite as good as the other precautions, but it definitely reduces the > possibility of nasty stuff getting through the latex and onto my skin. > > Jim Hocut jhocut@mindspring.comJim, Having been there, I am now using the 2427 and still itching. I had a violent reaction to the RAE epoxy several years ago. I'm talking emergency room type reaction. I immediately switch to SAF-T-POXY & SAF-T-POXY II. Still had reactions - not as severe. With the 2427 I still have skin rashes (right now for example). I get tissue reactions (sympathetic) in places where you do not desire reactions. I use butyl gloves covered w/ latex to protect the butyl ($$$$). I have use the same butyl gloves for 7 years, About time to change them out. I thought of using only latex gloves, but, latex is porous. Furthermore, I think the increase in tissue moisture inside the gloves (sweat) increases the likelyhood of a reaction. I don't have documented research on this, but past trends seem to point in this direction. All I can say is that what ever form of protection you select to use - BE CAREFUL. When I get a spot of epoxy on a area that is unprotected I immediately wipe the spot clean w/ laq. thinner. This seems to help somewhat. The vapors are also a real problem to those who have developed reactions. My 2 cents worth + a penny more - BE DAMNED CAREFUL epoxy sneaks up on you and kicks your ass when you least expect it. Steve Sharp Perpetual 3 place COZY builder - 8 years & still scratching - all over cozyiii@earthlink.net From: "Rob Cherney" Organization: Ellicott City, Maryland Date: Sun, 18 Aug 1996 10:09:09 -0400 Subject: Re: COZY: Epoxy Allergies Steve Sharp wrote: > When I get a spot of epoxy on a area that is unprotected I > immediately wipe the spot clean w/ laq. thinner. You shouldn't do this. The lacquer thinner will dilute the nasties and carry them through the skin. It's better to use a paper towel with soap and water and scrub. I have seen some people keep some of the wet baby towelettes in the shop for just this purpose. Rob- +--------------------------------------------------------+ |Robert Cherney Home Phone: (410)465-5598 | |Ellicott City, Maryland e-mail: cherney@clark.net | +--------------------------------------------------------+ Date: Sun, 18 Aug 1996 13:05:59 -0700 From: "Steven D. Sharp" Subject: Re: COZY: Epoxy Allergies Rob Cherney wrote: > > Steve Sharp wrote: > > > When I get a spot of epoxy on a area that is unprotected I > > immediately wipe the spot clean w/ laq. thinner. > > You shouldn't do this. The lacquer thinner will dilute the nasties > and carry them through the skin. It's better to use a paper towel > with soap and water and scrub. I have seen some people keep some of > the wet baby towelettes in the shop for just this purpose. > > Rob- > +--------------------------------------------------------+ > |Robert Cherney Home Phone: (410)465-5598 | > |Ellicott City, Maryland e-mail: cherney@clark.net | > +--------------------------------------------------------+Rob, Thanks for the input. However, I've been there - done that. Th problem I ran into was the area washed w/ soap/water was the epoxy seemed to smear and the result was a larger "burn". I found a paper towel saturated w/ lacq. thinner and wiping the area of the stray epoxy immediately after I detect it - folding the towel into itself after each wipe- works for me. I look for the dilution factor. I had discussed this with my dermitologist several years ago and this is what he recommended. Of course, I just made the final payment on his new ocean front beach house in the Grand Bahamas. I am at the point now where I am so allergic to epoxy Ijust live with the discomfort during the summer months. The winter months are for healing. Anyway, no matter how you protect yourself - this shit is dangerous. But, so is TNT, if handled properly it will be of great benefit. The same applies to epoxy. Enough said. Steve Sharp Scratching for 8 years cozyiii@earthlink.net Date: 20 Aug 96 01:06:57 EDT From: INFINITY Aerospace <72124.347@compuserve.com> Subject: COZY: Epoxy Allergies Hi to All, We just got back from vacation and our best Oshkosh ever. I'd like to thank the hundreds of builders who stopped by to express their support. We use a product called Derma Shield. This product comes out of the can like shaving cream, smells a little like angle food cake, and forms a barrier with and into the pores of your skin - it can not be washed off with soap and water, or any other chemical. It loughs off with your dead skin over several days from normal washing of your hands. Doctors and surgeons use this product to protect themselves from HIV / Aids in case they get a nick in their gloves. Then put Ply 9, Series 88, Invisible Gloves #1211, any other barrier cream, gloves or nothing else on your hands. We, and many others, have never had a reaction to epoxies using this product (knock on wood). If we use gloves, we first put Johnsons Baby Powder with corn starch on our hands. The corn starch seems to help absorb the sweat a little better, keeping our hands drier longer. For larger layups, we like to clean up our hands and change gloves several times. Derma Shield can be purchased from Aircraft Spruce or your local Derma Shield Dealer. Try the smallest can. You may not like it, or you may find it does not work for you. To save alot of money, become a dealer yourself if the product works for you. HTH. Infinity's Forever, EAA Member EAA Technical Counselor JD EAA Flight Advisor AOPA Member Test Pilot James D. Newman, President LCDR F-14 USNR INFINITY Aerospace P. O. Box 12275 El Cajon, CA 92022 (619) 448-5103 PH & FAX 72124.347@compuserve.com Home Page http://ourworld.compuserve.com/homepages/INFINITY_Aerospace Date: Tue, 20 Aug 1996 10:44:56 -0400 From: HighPlane@aol.com Subject: Re: COZY: Epoxy Allergies--vinyl gloves I'm using vinyl gloves, rather than latex, because I read somewhere (I THINK) that they're less porous than latex. I get them at Sam's; seems like they're about $7 or so for 120. No epoxy reaction yet--but then again, my exposures are, alas, fairly infrequent at the moment ... id <01I8S1GAURSG8ZPN6D@InfoAve.Net> for cozy_builders@hpwarhw.an.hp.com; Tue, 27 Aug 1996 17:30:24 -0400 (EDT) Date: Tue, 27 Aug 1996 17:30:24 -0400 (EDT) Date-Warning: Date header was inserted by InfoAve.Net From: Nick Ugolini Subject: COZY: Epoxy Can anyone give me a clear idea of what is the epoxy de jour (of the day, or hour). and where I can purchase it at.... I need to do some glass work on my plane, and it has been a long since I have purchased any supplies. Nick Ugolini unick@mail.charleston.net Varieze N89RS Date: Sun, 01 Sep 1996 10:01:54 -0400 From: "Douglas O. Powell" Subject: COZY: Epoxy - Aeropoxy Reformulated While at Oshkosh, I stopped at the PTM&W booth. The rep said that Aeropoxy PR2032/PH3665 had been recenty reformulated to reduce sensitivity to "amine blush" and also reduce the viscosity. PH3665 is the slowest of the three hardeners (2 hr pot life) used with the PR2032 resin (PH3417 has 15-20 min pot life, and PH3660 has 1 hr). Forgot to ask just when this reformulation occurred. 1) Has anyone used both the old and the new versions, and if so, how do the humidity sensitivity and viscosity/wet-out behavior compare? 2) Can anyone compare the new Aeropoxy vs Hexcel 2427? Thanks, Doug Powell Cozy MK-IV #293 powelldo@ix.netcom.com Date: Sun, 01 Sep 1996 14:26:41 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: COZY: Epoxy - Aeropoxy Reformulated Douglas O. Powell Wrote >1) Has anyone used both the old and the new versions, and if so, >how do the humidity sensitivity and viscosity/wet-out behavior >compare? I have used both new and old. The old left in a pump started to show clowdy in both the resin and hardener almost at once. The new stuff only the resin showed water first and then the hardener about a month later??? The parts we made out of both new and old were not vary stable after a 7 day cure (creep) after post cure we only found a 160 MAX Tg after a post cure of 190 degree and a slow ramp check after cooled NOT GOOD >2) Can anyone compare the new Aeropoxy vs Hexcel 2427? Blush and peel strenght was a issue for us because of humidity. I don't think I would use in fuel tanks. ??? Tg of 2427 was about 210 degrees from our test AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 phone/fax 910-961-2238 E-mail: JRaerocad@gnn.com http://www.windev.com/aerocanard Date: Tue, 03 Sep 1996 18:59:08 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: COZY: Epoxy Testing Nick Ugolini wrote: >What is the procedure for testing epoxy resin? mix up some and let full cure. scrach test with a nail and if it scraches white??? it OK AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 phone/fax 910-961-2238 E-mail: JRaerocad@gnn.com http://www.windev.com/aerocanard by InfoAve.Net (PMDF V5.0-6 #4800) id <01I91UOGPRHS8XRYPP@InfoAve.Net> for cozy_builders@hpwarhw.an.hp.com; Tue, 03 Sep 1996 18:04:05 -0400 (EDT) Date: Tue, 03 Sep 1996 18:04:06 -0400 (EDT) Date-Warning: Date header was inserted by InfoAve.Net From: Nick Ugolini Subject: COZY: Epoxy Testing I have some old epoxy (about 3 years old) BUT the cans and seals have never been opened. Some of the epoxy opened 6 months ago (used to repair my Snapper lawn mower) appears to be working just fine. I plane to use for non-structual uses, ie filling, surface layups........ What is the procedure for testing epoxy resin? Nick Ugolini unick@mail.charleston.net Varieze N89RS Date: Tue, 17 Sep 1996 07:27:54 -0400 (EDT) From: "George A. Graham" Subject: COZY: 2427 Epoxy Great news ! I talked with Gorden Bowen last night. He is away from his computer, hasn't seen email in over 4 mo. Hopes to get home in October. He said that the 2427 epoxy showed zero gain/loss in fuel, both aviation and auto during testing, same as STP and RAE. The resin is basically the same for all three, the hardner is slightly different, but the cured properties are almost identical. The complaints about 2427, center around it not being as forgiving as STP and RAE, as to high temps/humidity, and high C02 in the shop. A waxy film builds on partially cured layups, and in the hardner pump during the above conditions. Otherwise, it's as good as the others. This conversation was a great relief to me. Modified E-Racer #206 Strakes and Mazda Engine next George Graham {ca266@freenet.buffalo.edu} From: "Krasa, Paul" Subject: RE: COZY: 2427 Epoxy Date: Tue, 17 Sep 1996 09:37:04 -0400 Larry Schuler said: > > Maybe all epoxys have their traits, 2427 is the only one I have >worked > with so far. Glad to share the experience. All the epoxy resin systems that we are working with will exhibit this trait to some extent. I believe that it is caused by the exothermic chemical bonding which takes place in the epoxy/resin systems that we use. As the reaction takes place over time there are less unlinked chemical chains that can be formed. If this is true, then if fresh epoxy is placed on top of epoxy that has stared to set up there are fewer unlinked chemical chains for the new epoxy to link with thus the interface between the older layup and the new layup will be weak. In other words, the inner laminar shear strength of the two layers will be lower due to the lack of unbounded chemical chains. This would explain why Mark's layup came apart. This is probably only worth about a half a penny, but I hope it will sheds some light on the subject, and does not muddy the waters. Paul Krasa Long EZ 214LP !---*---! Project Status: Wing roots are fiberglassed to the strakes, and I'm just about finished sanding the underside of the wing. This week I will cut the wings back off. Next week, I will install the electric trim system for pitch and roll. 95% done 50% to go. An experimental airplane is never done. > Date: Tue, 17 Sep 96 11:27:26 est From: "Larry Schuler" Subject: COZY: 2427 Epoxy George Graham wrote: >I talked with Gorden Bowen last night. He is away from his computer, >hasn't seen email in over 4 mo. Hopes to get home in October. >He said that the 2427 epoxy showed zero gain/loss in fuel, both >aviation and auto during testing, same as STP and RAE. >The resin is basically the same for all three, the hardner is slightly >different, but the cured properties are almost identical. >The complaints about 2427, center around it not being as forgiving as >STP and RAE, as to high temps/humidity, and high C02 in the shop. >A waxy film builds on partially cured layups, and in the hardner pump >during the above conditions. FWW: I have noticed the film, but only when I do a layup when the humidity is generally over 60 to 70 % in my shop. I avoid the need to sand this off by always using peel ply..... the thin gummy layer is pulled right off with the peel ply. Light sanding is usually all I need to do. Aslo, as Marc has mentioned in the past, can't put fresh epoxy over a layer that has started to set (usually in an hour to 1-1/2 hour depending on temp {this is WELL before the gel stage}). Maybe all epoxys have their traits, 2427 is the only one I have worked with so far. Glad to share the experience. Did Gordon say anything about alcohol or other additives in auto gas? Larry Schuler MKIV-#500 Chap.6 Date: Tue, 17 Sep 1996 22:21:00 -0400 From: SBLANKDDS@aol.com Subject: COZY: COZY - 2427/2428 resin in florida My .02 on resin I started with safe-t-poxy II, it worked well, smelled like I was building something... I switched to 2427/2428 when I started the canard and noticed the hardner container of my pump seemed to separate and require mixing. I have no idea what this separation meant, but I did not want to build an entire plane and then change resins!!! Also it is harder to see the layups as you go, hard to see if it is wetted out well. It is almost clear in color. I bumped my right elevator tip when moving my canard wing before I floxed the end of the elevator. The outer 5" of the underside delaminated quite easily and came off the foam. None of my older safe-t-poxy layers can be peeled at all. The layups looked good. When doing my repair I was able to separate the layers of glass further from the damaged area. This separated easier than I feel comfortable. I will finish the repair and flox the ends, but the canard will be checked often for any signs of delamination when finished. I am considering scraping the canard....to be determined. With our 80-100% humidity, don't use the 2427 resin. I'm back to the EZ 10 (safe-t-poxy) like stuff. This can be purchased from Jeff Russell at Aerocanard. Most recent Price =$130 / 2 gallons + shipping. E-Mail Jeff at: jraerocanard@gnn.com Steve Blank Cozy Mark IV #36 Attaching canard, cutting winglets, having fun! Date: Wed, 18 Sep 1996 23:51:28 -0500 From: Neil Clayton Subject: COZY: 2427; change of manufacturer I ordered two galls of 2427 and it came under the label; "H B FULLER" as the manufacturer, not "Hexcel". Anyone know why the change? What about mixing the new stuff with the old? Thx Neil From: "Steve Campbell" Subject: RE: COZY: 2427; change of manufacturer Date: Thu, 19 Sep 1996 07:47:05 On Wed, 18 Sep 1996 23:51:28 -0500, harvey3@worldnet.att.net wrote... >I ordered two galls of 2427 and it came under the >label; "H B FULLER" as the manufacturer, not "Hexcel". > >Anyone know why the change? >What about mixing the new stuff with the old? > >Thx >Neil > H. B. Fuller bought out that division of Hexcel a few months ago. It's the same stuff from the same people, just a new name. Steve Campbell **************************************** Stephen A. Campbell Associate Professor, EE University of Minnesota ***************************************** Date: Sun, 13 Oct 1996 08:03:53 -0400 (EDT) From: "George A. Graham" Subject: COZY: Fuel & 2427 Epoxy Does anyone know who has the epoxy samples soaking in fuel ? As you might know, my strakes are completed with the 2427. Thanks in advance. George Graham Modified E-Racer # 206 Mazda Engine Installation (716) 874-3277 Date: Mon, 14 Oct 1996 11:11:37 -0400 From: AlWick@aol.com Subject: Re: COZY: Fuel & 2427 Epoxy I've been soaking some foam and 2427 in gas for about 6 months now. 2 months ago I changed fuel in jar to stuff with alcohal (sp), no effect. The only way I know it has alcohal is that the fuel destroyed my gaskets in weed trimmer. -al Date: Tue, 15 Oct 1996 09:10:18 -0400 From: AlWick@aol.com Subject: COZY: Fuel & 2427 Epoxy My fuel testing totally subjective. Just put some gas in mason jar, threw in piece of strake foam and section of glass/epoxy layers. Put lid on it and let it sit for few months. To date no visible signs of degeneration, layer seperating, etc. I did this when I saw an ultralight fuel tank totally eaten away by the new fuel. The sealer was just a bunch of goo that plugged inlet. Resin was eaten out of first couple glass layers. -al Date: Tue, 15 Oct 1996 12:11:32 -0700 From: Chris van Hoof Organization: C van Hoof - Architect Subject: COZY: Epoxy Hi, This Cozy builder would like to get hold of some spec to the Epolite 2427 I am presently using another System by Hexcel called Epolam 2022 Spec and description as follows:- EPOLAM 2022 Epoxy laminating system - High performance Tg 100C. PHYSICAL PROPERTIES Resin Hardener Mixing ratio by weight 100 40 Mixing ratio by volume 100 50 Aspect:liquid Colourless Colourless Brookfield viscosity at 25C 1600+-200mPa.s 40+-5mPa.s Specific gravity at 25C 1,17+-0,02 0,94+-0,02 Mixing viscosity at 25C 600+-100mPa.s Mixing specific gravity at 25C 1,10+-0,02 Pot-life (280 g) at 25C 1 h 05 min +- 5min MECHANICAL AND HEAT RESISTANCE PROPERTIES Final hardness* ISO 868 Shore D 85+-2 Tg (DSC)* C 100 Flexural Strenght* ISO 178 MPa 125+-10 Flexural modulus of elasticity* ISO 178 MPa 3400+-200 Tensile strength* ISO 527 MPa 58+-5 Demoulding time at room temp h 24-36 Complete hardening time at room temp d 7 N B These values were determined on pure resin (without any fillers or fabric) * The above properties obtained with standardized specimens and in precise chemical crosslinking conditions correspond to optimum values of the system after complete hardening. Note from the Cozybuilder #219 - All the above info copied as to the best of my reading and typing skills, and same info is available in hardcopy form by asking Hexcel France/ Hexcel GmbH / Hexcel Espana and Hexcel Italia ( more info if you request same from me) Another Cozy builder in a the Durban area, found that the hot temperatures in his area shortened the potlife and changed to the "sister"system Epolam 2023 - this has a potlife on the above info of over 3 hrs. Please help us obtain similar info to the Epolite 2427. Thanx. Chris #219 with Cozy into chapter 8 cvh@iafrica.com Date: Thu, 17 Oct 1996 14:02:19 -0400 From: DFinn7971@aol.com Subject: COZY: Ratio Changes for Epoxy Pump Hello everyone! Jim Rios, my Cozy Classic buddy, is planning to switch from Safety Poxy to an as yet unnamed brand. I gave him the archives relating to the pro's and con's of the various choices. He asked that I post a note requesting a description of how the ratio pump (he has the sticky stuff dispensor) would have to be modified to accomodate each of the various chaoices. My memory is that you need to change the pivot point but I don't know how. Could anyone who has the specifics for the various epoxies please publish them. Thanks, Dick Finn Cozy Mark IV #46 DFINN7971@AOL.COM Date: Mon, 21 Oct 96 21:27:10 -0800 From: Eric_Westland@msvl.wednet.edu (Eric Westland) Organization: Marysville School Dist. Subject: COZY: 2427/Fuel/Crash I know we have had several discussions about the use of 2427 and most recently, a short dialog on 2427 and fuel compatability. What causes me to bring this up again is a Central States Association Newsletter article contributed by Valerie Harris, wife (?) of Robert whose Cozy was destroyed. It is quite short and the author asks that this be passed on, so copyright issues are probably not a concern. During a flight test, the engine stopped which resulted in the crash. They go on to say, " We had a lab in Boston test samples from the strakes and found the 100LL fuel in the tanks started to disolve the 2427 resin and flox causing small flakes. These went through the tank screens and were caught in the gascolator which has a finer filter. The gascolator had been checked 5 hours earlier. We had the lab run the same tests using RAE and the Safe-T-Poxy Resins. There were no problems with these resins. Please pass on again the warning about Epolite 2427 Resin". Here in the low humidity Pacific Northwest, I have had good luck with 2427. My strakes are complete, leak tested and ready to finish. I don't want to have to do them over, but the picture they sent along is very sobering. I will if there are unanswered questions. Is there an issue here? I would guess I am not the only one to reach this point with the 2427, what have others discovered? Could the lab in Boston be jumping to the wrong conclusion? This accident was news to me, do others know any additional details? Sleepless in Seattle, Eric -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Sent via ExpressNet/SMTP(tm), Internet Gateway of the Gods! ExpressNet/SMTP (c)1994-95 Delphic Software, Inc. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Date: Tue, 22 Oct 1996 09:27:11 -0400 From: DFinn7971@aol.com Subject: Re: COZY: 2427/Fuel/Crash In a message dated 96-10-22 03:22:26 EDT, Eric_Westland@msvl.wednet.edu (Eric Westland) writes: << We had a lab in Boston test samples from the strakes and found the 100LL fuel in the tanks started to disolve the 2427 resin and flox causing small flakes >> Ovewr the past few years I've occasionally wondered about the use of fuel cells. Alternatively, bonding the fuel cell material to the inside of the tanks with some type of adhesive. I'll be building my strakes in the not too far distant future and wonder if this idea has been tried. Dick Finn Cozy Mark IV #46 DFINN7971@AOL.COM From: Marc J. Zeitlin Subject: COZY: 2427/Fuel/Crash (fwd) Date: Tue, 22 Oct 96 11:08:11 EDT Eric Westland quoted: >.......... " We had a lab in Boston test samples from the strakes and found >the 100LL fuel in the tanks started to disolve the 2427 resin and flox causing >small flakes. These went through the tank screens and were caught in the >gascolator which has a finer filter. The gascolator had been checked 5 hours >earlier. We had the lab run the same tests using RAE and the Safe-T-Poxy >Resins. There were no problems with these resins. Please pass on again the >warning about Epolite 2427 Resin". >Is there an issue here? I would guess I am not the only one to reach this >point with the 2427, what have others discovered? Well, a few people have had samples of 2427 sitting in gas for a while, and have not seen any degradation, even after months of soaking. Clearly not proof of anything, but some evidence, anyway. It's very difficult for me to imagine that a _brand new_ plane undergoing flight testing could _possibly_ have had enough time (especially after being checked 5 hours earlier) for the fuel to degrade the epoxy enough to have this happen - it just always seems to have been a very long term thing when it's happened in the past. I don't know the Harris's from a hole in the wall, but I'd guess that whatever was clogging the gascolator wasn't _caused_ by the fuel degrading the epoxy. It's certainly possible (and even probable) that the "flakes" were epoxy and flox, but I'd guess that they were _caused_ by something other than the fuel. We all know that dust and bits of epoxy and flox can get everywhere, and maybe this stuff just got shaken loose after a few hours of flight. >.................. Could the lab in Boston be >jumping to the wrong conclusion? Depends on what they were told, and what samples they were given. We don't know either of these things. The evidence you're given determines the conclusion you come to. The RAE and SP the lab was given did _not_ come out of the COZY. The flakes they were given did, and clearly were the cause of the gascolator clogging. The lab would need to do a side by side blind test of the different kinds of epoxy in fuel to determine what, if any, degradation of the epoxy there would be. -- Marc J. Zeitlin Email: marcz@an.hp.com Subject: COZY: Tg and such Date: Tue, 22 Oct 1996 11:54:13 -0400 (EDT) From: "Randy Smith" I have been following the thread about painting the plane some "non-white" color. I understand that there is a limit to the temperature that the plane can withstand. Help me understand this a little more... Is the limiting factor the epoxy system that we use? Is the limiting factor the foam products that we use? Is the limiting factor the e-glass that we use? Is the limiting factor the construction method that we use? What does Tg refer to? What does it stand for? Is it possible that there exists an alternative material for one or all of the materials above that would withstand elevated temperatures? Lots of questions about technology that was developed in the '70s. Surely there have been improvements along the way. -Randy --* --- -* **-* *-** -*-- -* Watch this space for COZY progress |Cozy MkIV| NCR General Purpose Computing Randy.Smith@ColumbiaSC.NCR.COM |---( )---| Global Support Center Voice 803-939-7648, V+ 633-7648 ___o/o\o___ West Columbia, SC 29170 "I am the way, the truth, and the life..." -JC Date: Tue, 22 Oct 1996 11:58:21 -0400 From: AlWick@aol.com Subject: Re: COZY: 2427/Fuel/Crash In a message dated 96-10-22 03:22:18 EDT, you write: << small flakes. These went through the tank screens and were caught in the gascolator which has a finer filter. The gascolator had been checked 5 hours earlier. We had the lab run the same tests using RAE and the Safe-T-Poxy Resins. There were no problems with these resins. Please pass on again the warning about Epolite 2427 Resin". >> Eric, thanks for providing this info. I'm just a couple days from closing my first 2427 fuel strake. Was not aware of this info. Puzzled that my samples that have been sitting in auto fuel for past 6 months show no effect, even replacing fuel with some known to contain alcohal (sp). I'm going to pull my sample pieces and flex them tonight to see if any effects. Anyone with ideas on why we appear to have a disparity in 2427 performance results? Is there any other info that suggests 2427 can't handle fuel? Thanks. -al by Npt.NUWC.Navy.Mil (PMDF V5.0-5 #13155) id <01IAXYF4JV1W94DOW0@Npt.NUWC.Navy.Mil> for cozy_builders@hpwarhw.an.hp.com; Tue, 22 Oct 1996 12:04:56 -0400 (EDT) (4.1/SMI-4.1) id AA17696; Tue, 22 Oct 1996 12:05:30 -0400 (EDT) Date: Tue, 22 Oct 1996 12:05:30 -0400 (EDT) From: triley@c38fs0.npt.nuwc.navy.mil (Tom Riley) Subject: COZY: Cozy: 2427 EPOXY WARNING Dear fellow builders, I'm writing this to document problems I have had with 2427 epoxy. It's a bit long-winded and includes some background that I feel is necessary, to see how things evolved. When I started building my MKIV, I had no fiberglass experi- ence and the epoxy of choice was SafetyPoxy II. I had read accounts of builders developing alergies to RAE and decided to go with the flow and use the new "safe stuff". In retrospect, I should have gone with the old standby (RAE) as I'm about to do now. The only incident I had with SafteyPoxy was early in the game while building one of the bulkheads. Several hours after laying up one the the simple bulkheads, I decided to give the = glass a little tug just to see how secure the glass to foam = bond was. To my amazement and shock, the glass lifted easily and I thought that I might have picked up a corner that had not been wet out properly, but the whole thing looked good. There were no bubbles, dry glass, etc and I'm sure I prepped the foam with the proper consistency of micro. I continued to pull on the glass and the whole thing lifted off in one piece without any damage to the foam. = = You can imagine the uncertainties and "what ifs" that started flying through my head. I wondered (and hoped) that I had just = not allowed sufficient cure time, so I built another bulkhead in exactly the same manner. I allowed this one to cure for two days and I couldn't pull the glass off the foam. I chalked the experience up to insufficient cure time and went on. To date, I have had no other problems with the strength or peel resis- tance of layups done with SafetyPoxy. = My wife had a serious problem with the smell. She's a very = tolerant person and puts up with a lot of inconveniences with = no complaining, but the smell was giving her headaches (I'm = working in the basement) and making her sick. Also, I didn't = realize that the high viscosity and tendency of SafetyPoxy to = gell in the cup was making for difficult, time consuming layups 'cause I had nothing to compare it with. I guess the prospect of "stinking up the house" and many other factors led me to put the whole project on hold for a long time. I didn't knowingly make that decision, but that's = what happened. Several newsletters later I got geared up to get back into it and by then, SafetyPoxy had been replaced by the newer 2427 = epoxy. From what I read about it's lack of odor and lower vis- cosity, I was eager to try some and placed an order with Wicks. My first layups (the outside skin of the fuselage) went very well and I found it much easier to use (wet out) and my wife couldn't even tell when I was using it. Life was great. Several parts later everything was going well (I think) until = I was doing the landing gear reinforcements inside the fuse. I = think by this time I was on my second gallon. I never liked the knife trim technique and always wait for cure then trim = with a hacksaw and file. While trimming one of the reinforce- ments, I caused a small semicircular delamination about the = size of a quarter. I immediately remembered my experience with SafteyPoxy not having cured enough and attributed this to be the same. I let it cure another day and was more careful when trimming not to pull up on the cloth. I've since seen several small delaminations at the edges when = trimming, or around the perimeter of a drilled hole and con- tinued to think (and hope) that it was due to insufficient cure = time ........ until now. I recently finished the torsional layups on the main gear and it looked great. I then put the first (outside) layups of the attach tabs in place, then after at least a three day cure I = cut them to size, drilled the 1/4" pilot holes and trimmed the = excess that goes over the underside of the strut. After cutting partway through with a hacksaw, I was convinced that this was going to be no simple feat to tear off the stubs of excess = glass. I put a wood chisel into the piece and started to pry, = and an entire piece peeled off like it was a banana peel! I continued doing this, and layer-by-layer, the pieces peeled off easily. I was sick. I called Nat and relayed these experiences to him and he is quite concerned. I've since sent him and a Cozy builder/friend some samples of the cutoffs and am awaiting their analysis and = recommendations. Nat said that he has had no similar experience = with the 2427 he has used but suggested that my coastal loca- tion (SE Massachusetts) and considerably higher humidity could = be a factor or it could just be a bad batch, or it could be a basic flaw in the product. I have read the past emails about = one of you that got a cloudy batch of 2427, but mine has been = crystal clear. I keep it in an "oven" at about 90=B0F. If humi- dity or CO2 is the problem, then covering the pot with a piece of plastic to prevent the entry of water of CO2 is not the solution. We can't work in a vacuum. From what I've heard, RAE never had this hypersensitivity to its environment. It is possible that I may have gotten a bad batch, or at least a different one. As I remember, my first gallon (which I think worked OK, and will positively determine this weekend when my friend and I do some hopefully non-destructive tests) was from Hexcell. The gallon I'm now using was labelled H.B. Fuller. I know it's the same company, but did Fuller change the formulation when they bought out Hexcell? Last night I decided to probe the landing gear tabs a little further. I tapped a wood chisel into the edge of the tab very gently and it separated like butter. A not-too-hard sideways rap on the tab with a hammer (certainly less energy than would be expected in a "bad" landing) completely tore the tab from the strut. Today is the 21st and this part was laid up on the 16th. In peeling off the tab, some of the torsional layup underneath showed signs of delam. I pried these up and found that I could peel the entire torsional layup off, layer-by- layer, like it was wallpaper. I think it's an understatement to say that I'm disgusted. A used 172 is starting to seem not that unattractive. But one thing I've got is patience and persistence, even if I absolutely despise doing things over again. I've since called Wicks and ordered some RAE slow. Mr. Haddager was very helpful and un- derstanding and asked if I could send him a sample of the = "cured" pieces together with some of the liquid epoxy. This I am doing, but no matter what the outcome, I'll never use 2427 again. In fact, I'll never use ANY new gallon of epoxy without first laying up a sample piece and testing its cured properties. I hope documenting this sad experience will save some of you = from the same fate. Tom Riley MKIV, S/N 113 = = = = by Npt.NUWC.Navy.Mil (PMDF V5.0-5 #13155) id <01IAXZL4LDJ894DOW0@Npt.NUWC.Navy.Mil> for cozy_builders@hpwarhw.an.hp.com; Tue, 22 Oct 1996 12:38:51 -0400 (EDT) (4.1/SMI-4.1) id AA18227; Tue, 22 Oct 1996 12:39:26 -0400 (EDT) Date: Tue, 22 Oct 1996 12:39:26 -0400 (EDT) From: triley@c38fs0.npt.nuwc.navy.mil (Tom Riley) Subject: COZY: P.S. on 2427 P.S. After playing with the attach tabs, I went back and inserted a knife edge in the quarter-sized delam that I had originally seen on the landing gear reinforcement. It was laid up at least 8 weeks ago. It, too peeled up with little resistance. Believe me, all surfaces were properly sanded, vacuumed and coated with epoxy before putting reinforcements in place. Also, the attach tabs separated BETWEEN layers, so surface preparation is not the issue here. In doing layups with several layers of cloth, I have never seen any evidence of a waxy buildup on the intermediate surfaces, as reported by others. Tom Riley Date: Tue, 22 Oct 1996 11:49:31 -0500 From: Mahan Subject: Re: COZY: 2427/Fuel/Crash There is always junk in your fuel system, no matter how careful you are during construction. Examples are bits of cotten flock, blobs of flox, flakes of dried epoxy from pulling off peel ply, dust, dead insects, etc. Check your gascolator and filters often during the first 50 hours. Fred in Florida Long-EZ N86LE Date: Tue, 22 Oct 1996 10:17:23 -0700 From: berkut@loop.com Subject: Re: COZY: Tg and such > >I have been following the thread about painting the plane >some "non-white" color. I understand that there is a limit >to the temperature that the plane can withstand. Help me >understand this a little more... > >Is the limiting factor the epoxy system that we use? >Is the limiting factor the foam products that we use? >Is the limiting factor the e-glass that we use? >Is the limiting factor the construction method that we use? > >What does Tg refer to? >What does it stand for? It's the glass transition temprature - basically, the temp at which the epoxy softens. Epoxys tend to have a Tg somewhat related to their cure temp. Safety Poxy's is about 195 f. Other systems go to hundreds of degrees, but they also need higher tempratures to cure. A middle ground is some of the tooling resins, which will cure to free standing at room temp but need a post cure to a higher temp before they reach full strength. The styrofoam will start to soften and swell at about 150-160 degrees. The PVC is good to about 180-190 - if you want to bend it you can put it in boiling water. Urethanes are good for very high temps (take a 1" thick slab of 8 lb urethane, put an oxy acetelene torch on it, it'll take close to a half hour to burn through. There are methods (vinyl esters, honeycomb cores and such) to go to higher temps, but they all come with their own limitations. -- Czech Sikhs! Richard Riley "The important things are always simple. The simple things are always hard." See the Berkut at http://www.berkut.com Date: Tue, 22 Oct 1996 13:17:26 -0400 (EDT) From: "Larry Schuler" Subject: COZY: 2427/Fuel/Crash Eric wrote: > We had the lab run the same tests using RAE and the Safe-T-Poxy Resins. >There were no problems with these resins. Please pass on again the warning >about Epolite 2427 Resin". I hadn't heard of the crash either. Most important, It would be very good to see complete copy of ALL of the lab reports before jumping to any conclusions. Suspitions abound in all aspects of what we do/don't do; it's easy to get ulsers without all the info. Eric, what are the chances of posting the reports here? quietly working on an ulser, Larry Schuler MKIV-#500 Ch-6 Date: Tue, 22 Oct 1996 13:42:47 -0400 From: DevoCoach@aol.com Subject: Re: COZY: Tg and such In a message dated 96-10-22 12:26:48 EDT, randys@majik35.ColumbiaSC.NCR.COM (Randy Smith) writes: >I have been following the thread about painting the plane >some "non-white" color. >Is the limiting factor the epoxy system that we use? >Is the limiting factor the foam products that we use? >Is the limiting factor the e-glass that we use? >Is the limiting factor the construction method that we use? >What does Tg refer to? >What does it stand for? The limiting factor, according to Stan Montgomery, who taught the former Alexander Aircraft composite course, is the epoxy. Tg refers to transition of glass, the temperature at which cured epoxy actually begins to "unharden". The Tg is determined by the temperature at which the epoxy originally cures. I believe the rule of thumb he used to determine Tg for most epoxies we use is 40 degrees above cure temp. If allowed to cure at 70 degrees, the Tg would be 110, at 90 degrees tg would be 130. On a 95 degree day on an airport ramp, temperature on the aircraft skin could well be 140 degrees. Obviously, you can see the problem of painting a composite aircraft dark red! In fact, several years ago, a northern builder flew a brand new EZ to Sun n Fun. In the hot Florida sun, the wings actually drooped! Stan recommends postcuring all composite structures to increase Tg. A process that basically subjects the composite structure to increased heat (although not enough heat to melt the foam core... that would ruin your day!) Stan recommends "baking" parts for a 24 hour (dont quote me on duration) period at increased temps (110 -120 degrees). He also said that Tg will increase over time as parts are repeatedly subjected to heat. The lesson learned is that your airplane definitely has limitations based upon its Tg! A darker skin color will only increase the liklihood that your Tg limitation will be reached. Jeff Mallia Cozy III > > Date: Tue, 22 Oct 1996 14:55:04 -0400 From: AlWick@aol.com Subject: Re: COZY: 2427/Fuel/Crash In a message dated 96-10-22 11:09:16 EDT, you write: << hole in the wall, but I'd guess that whatever was clogging the gascolator wasn't _caused_ by the fuel degrading the epoxy. It's certainly possible (and even probable) that the "flakes" were epoxy and flox, but I'd guess that they were _caused_ by something other than the fuel. We all know that dust and bits of epoxy and flox can get everywhere, and maybe this stuff just got shaken loose after a few hours of flight. >> I think Marcs evaluation holds some value. My fuel tank is full of flakes right now, due to the sanding and sawing I've been doing. I've seen resin (poly resin? in old ultralite tank) and grey sealer affected by gasahol, resulted in gue similar to that slime stuff they sell to kids. Not flakes. For what it's worth. -al Date: Tue, 22 Oct 1996 16:47:04 -0400 From: "Larry Schuler" Subject: COZY: Cozy: 2427 EPOXY WARNING Tom Riley wrote: >I put a wood chisel into the piece and started to pry, >and an entire piece peeled off like it was a banana peel! I >continued doing this, and layer-by-layer, the pieces peeled off >easily. Got me thinking. Could this be caused by the epoxy not bonding to the glass? I had heard of some glass made by Burlington in years past that had this problem due to a sizing agent added during weaving process. Thought it had all been taken off the market.... Just a thought. Larry Schuler MKIV-#500 Ch6 Date: Tue, 22 Oct 96 23:52:40 -0800 From: Eric_Westland@msvl.wednet.edu (Eric Westland) Organization: Marysville School Dist. Subject: Re: COZY: 2427/Fuel/Crash -Reply burgerr@telkom.co.za,Internet writes: Eric, I'm in South Africa, Port Elizabeth to be exact. Let's get this under the belt A.S.A.P I'm about to skin the top of the strakes soon. 1. flakes could have been due to poor sanding before coating with epoxy to cover pin holes. We all make mistakes. 2. Maybe we must drain more vigorously for the first 40 hrs of testing time? Q: WHAT does Hexcell have to say? Gordon Bowen was stated to have tested the stuff? Nat has approved 2427 But states in the plans to rather use safe-T . We in the sticks here. It takes months before I get supplies. Please get us an e-mail to Hexcell or the new company A.S.A.P Rego Rego, I found a little more out today via the net. I have not verified any of this with the principles, but here is what I found : The FAA database (Landings) lists the Harris's plane as a "Merle Musson Cozy". The owner _may_ not have been a full participant in the building of the plane. I also looked up what I am 95% sure (No tail number was given in the CSA article) is the NTSB accident report. Here is what it said : NTSB Identification: ATL96LA085 Accident occurred MAY-07-96 at COVINGTON, TN Aircraft: MERLE MUSSON COZY, registration: N86LM Injuries: 1 Minor. On May 7, 1996, about 1335 central daylight time, a Merle Musson Cozy, N86LM, nosed over during a forced landing at Covingtion, Tennessee. The airplane was operated by the pilot under the provisions of Title 14 CFR Part 91, and visual flight rules. Visual meteorological conditions prevailed. A flight plan was not filed for the personal, local flight. The private pilot had minor injuries, and the airplane was substantially damaged. The flight originated about 30 to 40 minutes prior to the accident at the Covington Municipal Airport, Covington, Tennessee. According to the pilot, he was conducting a post maintenance check flight following the replacement of the carburetor about 4 days prior to the accident. After flying above the airport about 40 minutes with no discrepancies, he entered the landing pattern. During the go-around of a touch and go landing, the engine quit about 150 feet above the ground. The airplane was landed in a wet, muddy field which resulted in a nose over at touchdown. Of course, the part that got my attention was the "replacement of the carburetor about 4 days prior to the accident". That's not to say the lab report was in error or that the 2427 was not part of the problem - the NTSB report just does not go into that. I am not making any judgements at this time or drawing any conclusions. To be perfectly honest, I am not qualified to judge the fuel compatability of 2427 or determine the cause of any accident. I do however want to get to the bottom of this 2427/fuel compatability issue - at least to the point that I know it is safe. I wrote the Harris's today asking for more details along with a copy of the lab report. I also wrote Nat to see what he knew. When I find something further, I will pass it along. In the meantime, I would like to continue to hear what others more knowledgable in these area think. Later, Eric -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Sent via ExpressNet/SMTP(tm), Internet Gateway of the Gods! ExpressNet/SMTP (c)1994-95 Delphic Software, Inc. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- by Npt.NUWC.Navy.Mil (PMDF V5.0-5 #13155) id <01IAZAP2KTO894DOW0@Npt.NUWC.Navy.Mil> for cozy_builders@hpwarhw.an.hp.com; Wed, 23 Oct 1996 11:07:21 -0400 (EDT) (4.1/SMI-4.1) id AA29333; Wed, 23 Oct 1996 11:08:01 -0400 (EDT) Date: Wed, 23 Oct 1996 11:08:01 -0400 (EDT) From: triley@c38fs0.npt.nuwc.navy.mil (Tom Riley) Subject: COZY: 2427 WARNING Rego Burger wrote: Rego, Thanks for your reply, and I can imagine the difficulties you must have in getting supplies to S. Africa. I disagree with your acceptance that "all laminates will chip/delam when drilling holes." I never saw this with the SafetyPoxy. In fact, I have several cut offs left over from when I was using SafteyPoxy, and have since performed des- tructive testing on them after going through this 2427 fiasco. I couldn't tear apart any of thoses samples without completely shredding the thing. Its structure and strength were similar to G10 epoxy/glass printed circuit board material. Have you ever tried to destroy one of those green printed circuit boards? Damned near imposible, and that's how your airplane should be too. Well, the SafetyPoxy parts were just like this. On the other hand, the 2427 samples peel apart like multiple layers of wallpaper, even after extensive curing. You owe it to yourself to try pulling apart some old cuts hanging around or some inconspicuous parts of your airplane that can easily be repaired. I think I know the thought process you're going through, 'cause I went through it. It's kind of like you suspect there's something very wrong, but you really don't want to prove it to yourself because of all the time you've got invested. Prove it to yourself. I sincerely hope you find that all of your parts are sound and won't come apart, but I suspect that this won't be the case. Tom Riley by Npt.NUWC.Navy.Mil (PMDF V5.0-5 #13155) id <01IAZB1RXHAS94DOW0@Npt.NUWC.Navy.Mil> for cozy_builders@hpwarhw.an.hp.com; Wed, 23 Oct 1996 11:17:40 -0400 (EDT) (4.1/SMI-4.1) id AA29471; Wed, 23 Oct 1996 11:18:13 -0400 (EDT) Date: Wed, 23 Oct 1996 11:18:13 -0400 (EDT) From: triley@c38fs0.npt.nuwc.navy.mil (Tom Riley) Subject: COZY: Re:2427 EPOXY LIKE JUNK Steve Blank wrote: ------------------------------------------------------------------------------- > Tom Riley, > > I read your e-mail with great sadness for the time investment. I built >my canard from the 2427 junk. When i took it ouside for a photo opportunity, >i bumped the corner of the elevator. It delaminated very easy. When i >separated the elevator from the canard and inspected the part, I found that >the glass came off the foam very clean. It had set for weeks. I then decided >to trim back to bevel the two layers so I could lay two new layers. To my >suprise, the next few inches separated between layers quite easy. :( > > I quit working for quite a while deciding if I should make a new >canard.... I may scrap it after your story. My surface is a little uneven and >will need a lot of fill and sand time. It may be better to just start over. > It is too important of a part to have a failure. The entire canard is 2427, >spars and skin. > > I just switched to the EZ-10 resin that Jeff Russell stocks (Aerocad). > It is very much like safe-t-poxy II, but lower in viscosity (subjective >measure) and takes 10-12 hours to cure in 75-80 degree south florida >humidity. Smells, but works great. No separation evident when i tried to >wreck it. I would suggest that all users throw out all 2427, unless the >parts are non structural, like control stick grips. I am not sure why you >and I had problems with this stuff. All my layups are by the book. No >hardshelling, no waiting between layers.... Not too dry, fibers straight, >etc... > > If you can reinforce any finished layups with a few layers of a better >resin, it might be a good idea. Any suggestion of what a scrap canard is >good for? > > Sorry to meet you this way, > >Steve Blank > >Cozy Mark IV #36 Fuselage complete, canard finished but not installed, >winglets glassed. Landing gear and speed brake ready to assemble. > >sblankdds@aol.com (561)337-3377 Port St. Lucie, >Florida > -------------------------------------------------------------------------------- Steve, Thanks for your comments and condolences. I haven't built the canard yet, so I don't know how much work it was. I think the outside skins on my fuse are OK, as I remember when I cut out for the wing spar, I didn't see any peeling. I'm going to find out for sure this weekend when a friend is coming over and we intend to test all existing 2427 layups. Again, thanks for the feedback. Tom Riley From: Marc J. Zeitlin Subject: COZY: 2427 WARNING (fwd) Date: Wed, 23 Oct 96 11:49:02 EDT Tom Riley writes; >circuit boards? Damned near imposible, and that's how your >airplane should be too. Well, the SafetyPoxy parts were just >like this. Agreed. >....... On the other hand, the 2427 samples peel apart >like multiple layers of wallpaper, even after extensive curing. Sometimes. > I sincerely hope you find that all of your parts are sound >and won't come apart, but I suspect that this won't be the >case. We've hashed through all this 2427 stuff many times, and as a builder who has put together one whole plane with SafetyPoxy I and 1/2 of this one with 2427, there's no question that 2427 is touchy and has a much higher chance of having a poor bond or delamination. However, I have performed some of the testing on my parts that Tom has described, and in all cases, I have satisfied myself that my laminations hold together, and that the interlaminar peel strength is acceptable. So, I don't think that it's a given that the 2427 is a problem - it just has a much higher chance of being one. That said, if someone asks me what epoxy to use, I'll recommend the RAE or the SPII (2410 or equivalent) or even the Gougeon Bros. Pro-Set (which I've never even seen, much less used) over the 2427. However, I do think it's possible (and it has been done) to build a structurally perfectly acceptable aircraft from 2427 (and I will do just that, until my 2427 runs out and I switch to something else) with appropriate care and testing. If, in your particular environment, you cannot get 2427 to behave, definitely switch to something else, and if you haven't started yet, start with something else. I have just got off the phone with Nat P. and he indicated that he will probably be recommending that people use a different epoxy, given all the problems that people have been reporting here, in CSA, and directly to him. -- Marc J. Zeitlin Email: marcz@an.hp.com From: "Richard William Crapse" Date: Wed, 23 Oct 1996 14:14:14 -0400 Subject: Re: COZY: 2427/Fuel/Crash -Reply Guys, I know these people and that Cozy. This Cozy was torn down to just the fuselage tub and rebuilt completely from there. The original builder used a Ford V-6 engine in it and had severely flawed flight controls, epoxy so thick it was in rivulets on the main spar and other vertical surfaces so thick you could not see the fiberglass. Robert and Valerie ahave rebuilt/built many projects into airplanes after they crashed, builder stopped, etc. Valerie has built 22 Long/Vari- EZes. Robert Has built about 30. Many of these are flying far faster than the plans say they should. Their qualtiy control is outstanding as they taught me how to glass, mix micro, etc. They also showed me how to do some of the "tricks" of laying up vertically, post curing, etc. I know they washed out the tanks 4 times before they flew it. It took approx. 20 gallons per tank per side per washout when they did it. I trust their workmanship and their skills. So does Burt. They are working on projects for him. Rick Date: Wed, 23 Oct 1996 14:15:59 -0400 From: AlWick@aol.com Subject: COZY: Re: 2427 EPOXY WARNING In a message dated 96-10-22 12:10:27 EDT, you write: << I've since seen several small delaminations at the edges when trimming, or around the perimeter of a drilled hole and con- tinued to think (and hope) that it was due to insufficient cure time ........ until now. >> I appreciate the warning, just 20 months too late. I started poking around on my finished parts and pieces last night. I too had noticed little signs of delamination, but since I knew I was applying epoxy correctly, didn't pursue. I'm NOT impressed with layer to layer adhesion. Poking with xacto knife on cut edge, it is not too difficult to separate layers. Not like peeling a banana, but not as good as expected. This is not a workmanship, environment, or epoxy shelf life issue. Here's the test: remove fully cured section using jig saw. Pry between layers with xacto knife. Peel layers apart. Observations: jig saw causes layers to separate at cut edge at places (2 to 3 mm). After poking around with knife, layers separate fairly easy (40 to 80lbs?). Anyone have similar results? -al Date: Wed, 23 Oct 1996 14:15:49 -0400 From: AlWick@aol.com Subject: COZY: 2427 epoxy and fuel Went home last night and messed around with the fuel soaked parts I have. My conviction is that 2427 is fully fuel compatable. No degradation. Now if I can only get rid of that gas smell..... -al Date: Wed, 23 Oct 96 11:59:35 -0800 From: Eric_Westland@msvl.wednet.edu (Eric Westland) Organization: Marysville School Dist. Subject: Re(2): COZY: 2427/Fuel/Crash -Reply rwcrapse@eos.ncsu.edu,Internet writes: I trust their workmanship and their skills. So does Burt. They are working on projects for him. Rick Rick, Thanks for the info - it sounds like they may be as qualified/experienced builders as one could find. Once again, I want to be sure that all are clear that I am not pointing fingers at anyone - I'll be the first to admit I am not qualified. Burt is however. If the Harris's used 2427 on the plane that crashed, are they using it on the one's they are building for Burt? Do you know what Burt's reaction to this fuel compatability issue might be? I don't expect a reply to my letter to the Harris's for a week with the mail-lag and all. If you talk with them in the meantime, I would love to know more details. Thanks, Eric -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Sent via ExpressNet/SMTP(tm), Internet Gateway of the Gods! ExpressNet/SMTP (c)1994-95 Delphic Software, Inc. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- by Npt.NUWC.Navy.Mil (PMDF V5.0-5 #13155) id <01IAZLHUNWNS94DOW0@Npt.NUWC.Navy.Mil> for cozy_builders@hpwarhw.an.hp.com; Wed, 23 Oct 1996 16:16:53 -0400 (EDT) (4.1/SMI-4.1) id AA03223; Wed, 23 Oct 1996 16:17:33 -0400 (EDT) Date: Wed, 23 Oct 1996 16:17:32 -0400 (EDT) From: triley@c38fs0.npt.nuwc.navy.mil (Tom Riley) Subject: COZY: 2427 EPOXY WARNING John Fritz wrote: -------------------------------------------------------------------------------- >Tom, > >I have had similar situations that you have described and am in the >process of trying to determine the cause and ultimately a viable >solution. Living in a humid climate, I bought a dehumidifier at the >beginning of the project to prevent and humidity problems that >had been associated with the 2427 epoxy. > >Here is what message I posted afterward I did the bottom layup per plans: > >------------------------------------------------------------------------------ >------------------- > > Subj: Chapter 6 Fuselage Interior Bottom Layup > Date: 95-12-08 03:33:20 EST > From: Fritzx2@aol.com > To: cozy_builders@hpwarhw.an.hp.com > > Hi Gang, > > The following is my description of the events prior, during, and after the > glassing of the fuselage interior bottom at the end of Chapter 6 for my MK > IV. > > The Saturday following Thanksgiving I glassed the inside of the fuselage > bottom as described in the plans at the end of Chapter 6. > > The layup, including all the 2 ply BID tapes, was completed in exactly 12 > hours as permitted in the plans in the last section of Chapter 6. The room > temperature during the layup was maintained at 73 degrees F. Hexcel 2427 > epoxy was used. > > At the end of 2 ply taping the interior fuselage bottom to mating surfaces, > there were doubts in my mind that I had not completed the taping soon >enough > to make a good bond between the newly glassed bottom and the 2 ply BID >tapes > even though I finished in 12 hours. To have some nondestructive means of > determining if my doubts were substantiated, I "taped" a leftover piece of >2 > ply BID tape to the interior of the fuselage bottom adjacent to where the > front wheel well will be. Not that this place was any better than anywhere > else, but rather it was accessible out from under the inverted fuselage >(and > after a loooooong day, that was a good thing). In a 16 oz mixing cup I had > some very thick leftover epoxy from the glassing of the fuselage bottom to > which I also taped an extra piece of 2 ply BID tape. After 3 days of >waiting > ( the hardest part), I attempted to remove the test tapes. As I suspected, > the test tape released from the bottom of the fuselage easier than peel ply > placed on the layup. The tape connected to the epoxy in the mixing cup > seemed harder to delaminate but easier than I thought it should be for a >good > bond. I knew at that point that it was time to remove some of the >permanent > tapes on the interior of the fuselage and try to determine how well they >had > bonded with the fuselage bottom. > > Without damaging the underlying skins, I removed the 2 ply BID tapes >(located > between both sides of the fuselage and from between the instrument panel >and > the front of the front seat) that joined the bottom of the fuselage to the > sides, bulkheads, and air duct 4 days after the marathon layup. I estimate > that the bond strength between the tapes and the newly glassed interior > fuselage bottom when compared to the same tapes attached to the sides >locally > sanded with 36 grit sandpaper to be approximately 50 % to 70 %. > > Interior fuselage bottom to 2 ply > BID tape interlaminate strength > ------------------------------------------------ ~= 50 to 70 % > Fuselage side to same 2 ply BID > tape interlaminate strength > > This ratio is meaningful only if the layup of the 2 ply BID tape to the > fuselage side was done properly and consistently which I'm pretty sure it > was. > > > In order to PREVENT DAMAGING the underlying structure, I could not apply a > pure shear > stress to the tapes as I think they will be stressed in service, but rather >I > was forced to apply a normal force to get the tapes to release. When > enough normal force was applied between the tape and the bottom to initiate >a > delamination, the propagation of the delamination can be best described as >a > popping loose. The delamination between the fuselage sides and the 2 ply >BID > tape was as I expected it to be for a good bond to a previous layup that >was > prep sanded with 36 grid sandpaper and epoxy painted before attaching a > subsequent layup. It is difficult to describe, but, if you have ever > removed a layup, hard point, or anything else that should have bonded to a > partially cured prior layup, you will know what I am trying to say and if >you > haven't, hopefully you will know what to look out for. > > To be honest, these observations are down right qualitative NOT >quantitative. > I am by no means an expert in the area of fiberglass reinforced composite > structures. In fact, this is my first attempt at building a plane. From > some engineering courses I have taken, though, I do know that interlaminate > strength is a very important factor in determining ultimate structural > strength. As far as I can tell, in the case of taping the interior sides or > bulkheads to the bottom, the interlaminate bond is the only means of > transferring the stress from tapes to bottom, sides, or bulkheads. Do NOT > misconstrue this information as reason to start ripping your plane apart. > Just keep it in mind when making future layups. > > I would welcome any comments or experiences anyone else has had regarding > subsequent layups applied to a partially cured previous layup. > > Please note that my email address has changed to AOL listed below. My > original inquiry to Marc was made while I was test driving Prodigy. I >tried > both AOL and then Prodigy and decided that I liked AOL better. > > John Fritz email: fritzx2@aol.com > >------------------------------------------------------------------------------ >-------------------- > >To repair the above, I removed all the interior bottom-to-sides/bulkhd tapes, >sanded everything rough with 36 grit, and reglassed the interior bottom with >2 inch >2 ply bid tapes. While I was not pleased that I had to do all that extra >work, >I was glad at the time that I checked the tapes, found that they were bad, >and I repaired them. > >After finishing the outside of the fuse, I completed the rear air duct and >the >reinforcements over the landing gear. Then it happened. I cut the >centerspar >section out of the fuse sides. I had not cut it out of the sides before >glassing >the outside because I didn't want the skinny top longeron sticking out >where it could get damaged accidently if I bumped it while flipping the >fuse or when walking around the fuse those million of times that you do >while working on it. After cutting out a piece of the fuse side at the >centerspar area, being a mechanical engineer, I took the opportunity to >do some destructive testing of the 3 UND ply on the outside of the sides. >Each UND layer seperated from the other once a delamination was >started. The propogation of the delamination was in my OPINION very (too) >easy. And to make a bad situation worse, the bottom layer of glass (the >first of the 3 UND layers applied to the micro on foam) peeled up leaving >all the micro still attached to the foam. The micro was sort of shiny >and had the imprint of the glass weave in it. I'm almost positive this is >indicative of inadequate peel strength. After that, I peeled the entire >layer of top >UND off the one side of the fuse and that's when progress on the plane >stopped. > >That was about a month ago and I have been doing a lot of research into >what happened. I would like to talk this over with you and compare notes. >I tried to get your phone number from an automated feature Marc Z. has >done with his server but was unable to get it to work. Please give me >your phone number and a time when it would be good to talk or give me >a call a home at 770 642 7481 in Georgia evenings after 7:00 pm. I also >sent a sample to Nat to look at but our hour long discussion is too much >to put into an email message. > >Regards, > >John Fritz >Fritzx2@aol.com > > -------------------------------------------------------------------------------- John, I will try to contact you by telephone as you requested. I reprinted your letter here so that everyone in the Cozy group could read about your experience too. I think it's very important that all 2427 user's hear ALL THESE HORROR STORIES so that they will be prompted to assess their own parts very carefully. I have tried to take some SafetyPoxy samples apart, and "ya just can't do it." There's no way I could pull things apart, layer-by-layer. I could only get little pieces, a bit at a time, and none of it peeled apart. It was a bit more like chiselling apart a piece of very dense particle- board. And that is how it should be. Again, thanks for your feedback, and I hope you didn't mind me reprinting it here for everyone's consumption, but I think it's important that the information be made availa- ble to all. Sincerely, Tom Riley Date: Wed, 23 Oct 1996 15:20:31 -0500 From: Mahan Subject: Re: COZY: Re: 2427 EPOXY WARNING Al Wick wrote: Here's the test: remove fully cured section using jig saw. Pry between layers with xacto knife. Peel layers apart. Observations: jig saw causes layers to separate at cut edge at places (2 to 3 mm). After poking around with knife, layers separate fairly easy (40 to 80lbs?). Al, from my 7 years construction experience with Safe-T-Poxy & the original Epolite, this is NOT normal for layups. If you drill or saw cut a "normal" layup, the fibers on the surface fray, but not the ones in the middle, and the sawing won't cause delamination, unless you get it so hot that the epoxy begins to soften. Sounds like your fibers in the middle aren't being supported when you make the cut. I can't find out any info on Safe-T-Poxy's peel strength, but the July 1979 Canard Pusher said, regarding the newly introduced Safe-T-Poxy, "RAF has done a considerable amount of testing of this material, and had found it to be as good or beter in all respects as the RAEF and RAES ... ." Perhaps someone out there has peel strength comparisons? Don't choose one epoxy system over another based on price. For the 17 kits required to build a Cozy IV, the difference in price between 2427 and E-Z Poxy is only $591, only 2-3% of the cost of the completed airplane. As for me, I'll be using E-Z 10 Epoxy resin and E-Z 83 Epoxy hardener on my Defiant, after I test them to my satisfaction. Fred in Florida Long-EZ N86LE Date: Wed, 23 Oct 1996 20:16:15 -0400 From: SBLANKDDS@aol.com Subject: COZY: 2427 EPOXY LIABILITY > This in response to Tom Riley and others like me that believe that our work is not the problem, but that the 2427 is providing inadequate bonding between structural layers. Even if some parts look good, how do I know that the internal spar is good? I don't. I believe this stuff is defective and should not be used in aircrafts. It may be a high humidity problem. I don't know. But that 2427 stuff is not nearly as cohesive as safe-t-poxy or EZ10 resin in my garage. Question: What is the liability of the supplier and or manufacuter? I have about $275 in my canard plus my unrecoverable time. Any lawyers in the group? Do we have a class action? Was this manufactured for this use? Do we have any recourse as a group? P.S. I have one unopened gallon kit of the 2427 stuff for sale (or a good home). NOT for aircraft use!!!! Steve Blank, Cozy Mark IV#36 Port St. Lucie, FL USA sblankdds@aol.com Date: Wed, 23 Oct 1996 23:13:56 -0400 From: Nigel Field Subject: Re: COZY: 2427 EPOXY LIABILITY At 08:16 PM 10/23/96 -0400, Steve Blank, Cozy Mark IV#36 Port St. Lucie, FL USA wrote: >Question: What is the liability of the supplier and or manufacuter? I have >about $275 in my canard plus my unrecoverable time. Any lawyers in the >group? Do we have a class action? Was this manufactured for this use? Do >we have any recourse as a group? > Steve, Is this for real, your joking right?? Please tell us your joking. Please tell us that the alarm bells went off at 20 DB above the threshold of pain with 50 or so Emails over the past 4 months raising more than a little doubt about the structural properties of 2427. Tell us that your not making structural parts from this stuff that may fail!! Tell us how legal action will solve the problem. Tell us why people are still using this stuff given the myriad of documented problems. Sorry Steve and to the others but I have been biting my lip following this issue in complete dis-belief for too long. Since I don't use it and never will, I stayed quiet but this one finally got to me. When is someone going to say DONT USE 2427 TO BUILD AIRPLANES. Thats the first question the lawyers will ask. Yes there are ramifications for many folks who have invested considerable time and money in their projects. Its real tough to ignore that, but stand back from it. Assess the situation clearly for what it is, as you would in your profession for any engineering problem. Consider the consequences. There is just too much evidence from too many credible builders to pretend that there isn't a problem. Even a reasonable suspicion should be enough and I would suggest we have that. The tragedy here is that there are many other good products available so why in Gods name are people still using 2427??? I would suggest that perhaps its time for some serious structural testing to destruction of a major structural assembly such as a wing or spar to determined if 2427 parts are airworthy for the designed stress. Perhaps a co-operative group effort with reimbursement for the selected sample. The consequences are too severe not to seriously consider this. There are more just than Cozys involved here too, others are finding the same and asking the same questions. I think law suits will just do what happened to General Aviation and Gates, Lycoming, Continental and many others. It will make a product we need, epoxy, all brands of epoxy, unobtainium. Lets clean up our own act first. We have the collective ability. Nigel Cozy III 75% built with Safety Poxy. Date: Thu, 24 Oct 1996 01:40:54 -0400 From: Lenpilot@aol.com Subject: Re: COZY: 2427 EPOXY LIABILITY In a message dated 96-10-23 20:20:07 EDT, you wrote: << cozy_builders@hpwarhw.an.hp.com > This in response to Tom Riley and others like me that believe that our > work is not the problem, but that the 2427 is providing inadequate bonding > between structural layers. > Even if some parts look good, how do I know that the internal spar is good? I > don't. > I believe this stuff is defective and should not be used in aircrafts. It > may be a high humidity problem. I don't know. But that 2427 stuff is not > nearly as cohesive as safe-t-poxy or EZ10 resin in my garage. >Question: What is the liability of the supplier and or manufacuter? I have >about $275 in my canard plus my unrecoverable time. Any lawyers in the >group? Do we have a class action? Was this manufactured for this use? Do >we have any recourse as a group? > P.S. I have one unopened gallon kit of the 2427 stuff for sale (or a good >home). NOT for aircraft use!!!! >Steve Blank, Cozy Mark IV#36 Port St. Lucie, FL USA sblankdds@aol.com Steve, First let me start by saying that I am NOT a lawyer, However if you are seriously considering suing Hexcell ( or whoever they are today) please let me know _before_ you do. That way I can buy enough epoxy NOW to finish my project. I am sure that any lawsuit by a group of homebuilders would not have an overall desired effect on us as a group. It could make it far more difficult to buy any "suitable epoxy" as homebuilders >Was this manufactured for this use? We are constructing aircraft in our homes for personal use (according to FAA rules). The line just above the lot number on my 4 cans of 2427 says "For Industrial Use Only!". I can not find any reference on the product that states it is manufactured for the purpose of constructing a homebuilt airplane. >What is the liability of the supplier and or manufacuter? The following is their warranty disclaimer (found on the side of every can) WARRANTY the following is made in lieu of all warranties, expressed or implied. Sellers only obligation shall be to replace such quantity of this product which has proven to not substantially comply with the data presented in the manufacturer's latest bulletin describing the product in the event of the discovery of a non-conforming product. Seller shall not be liable for any property loss or damage, direct or consequential, arising out of the use of or the inability to use the product. Before using the user shall determine the suitability of the product for his intended use, and user assumes all risks and liability whatsoever in connection therewith. Statements relating to possible use of our product are not guarantees that such use is free of patent infringement or is approved by any government agency. The foregoing may not be changed except by an agreement by an officer of seller. In reading this it would seem that they covered their A.S.S. (aircraft specialty spruce) In two ways. 1) industrial use only! ---- I don't think we are considered as an industry 2) Warranty disclaimer. ----It puts the responsibility of quality control on us, (ultimately where it really belongs anyway) I am sorry to hear you lost the time and money you invested in your canard. I will certianly replace my 2427 with safety epoxy after reading all the horror stories. I will use the remaining 2427 around the house, yard, cars, etc. There was some post a while back stating, something to the effect that the company who bought out hexcell was not interested in providing epoxy to homebuilders. I am sure if that is the case, they would really lose interest if they were hit with a lawsuit. Unfortunately we are the proving ground for this new product. The feedback sugests that it is not all that great. Having only completed chapter four I haven't had any problems using 2427. I will definately switch though. I used the safety epoxy that came with the composite practice kit (bookend etc) and was more impressed with it anyway. It's good to have a group where these concerns and problems are brought to light early enough to change things. I think the big lesson here (for me at least) is to test every layup, especially before going into something big. Leonard Farneth Cozy Mark IV # 522 Date: Thu, 24 Oct 1996 09:34:08 +0200 From: Rego Burger Subject: COZY: TESTING INTERLAM SHEER Too All Concerned: Re: the Wise 2427 WARNING! Some thoughts while I'm busy with the tests I'll be doing : Don't confuse the force required to "chip"/ pry a layer free with the "peel" force required to separate an already delaminated part? Once loose it takes very little to roll off a ply of micrscopic resin between cloth layups. Most resins are rated at about 40Mpa tensile strength. The healthy human finger-nail can take up to 100Mpa before splitting! If you pry a ply of a layup with an xacto knife with a handle of 150mm long e.g. you will be faced with something like this: 1. ) You apply pressure to insert the tip of a VERY sharp blade in between layers say 3 mm deep. 2.) You lever at the handle say only 100g of pressure. Take 100g X by the 150mm arm = 15000g.mm force. Now transfer this ratio to the 3mm imbedded blade between layers , 15000g.mm / 3mm = 5000g of force. 5000grams of FORCE ?? That's 5Kg over a minute area? Normal lift on a wing with wing loading of 20 lbs/sq.ft is about 9Kg /sq.ft . One will find about 90,000 mm sq. , in a square foot! So Normal wing loading is about 10g /sq.mm. or 62.5g / sq.in. Take the force to actually get a sharp blade in between the layers. Let's say you use a THICK blade on that xacto! e.g. .5mm thick. If you apply 100g of pressure on .5 x .5mm = .25mm sq. This amounts to 400g/mm sq. Blades are much thinner so the figure will be higher, this calculation is just for illustration purposes. That's a LARGE amount of pressure? This is NOT to encourage the use of any PRODUCT YOU! are not happpy with, just to encourage thought. Chew on it! Rego Burger P.E. S.A. Cozy Mk4 #139 From: "Kerry Lamb" Subject: Re: COZY: 2427 EPOXY LIABILITY - What is the real problem! Date: Thu, 24 Oct 1996 07:42:08 -0500 Nick makes some very good points here. One thing this points up, is whatever the cause of what the 2427 problem turns out to be, you should make a point of checking your layups. This is true no matter what resin system you use. Please, lets use a measure of sanity here...remember what lawyers have done to general aviation. Anyone have a good figure on how much of the price of a new 172 can be directly attributed to lawyers/insurance? Kerry Date: Thu, 24 Oct 1996 08:10:18 -0500 (CDT) From: Steven A Eberhart Subject: Re: COZY: 2427 EPOXY LIABILITY On Wed, 23 Oct 1996 SBLANKDDS@aol.com wrote: > > This in response to Tom Riley and others like me that believe that our > work is not the problem, but that the 2427 is providing inadequate bonding > between structural layers. > > Even if some parts look good, how do I know that the internal spar is good? I > don't. > > I believe this stuff is defective and should not be used in aircrafts. It > may be a high humidity problem. I don't know. But that 2427 stuff is not > nearly as cohesive as safe-t-poxy or EZ10 resin in my garage. > > Question: What is the liability of the supplier and or manufacuter? I have > about $275 in my canard plus my unrecoverable time. Any lawyers in the > group? Do we have a class action? Was this manufactured for this use? Do > we have any recourse as a group? > > P.S. I have one unopened gallon kit of the 2427 stuff for sale (or a good > home). NOT for aircraft use!!!! > > Steve Blank, Cozy Mark IV#36 Port St. Lucie, FL USA sblankdds@aol.com > IMHO Only! We are the manufacturers of our aircraft and as the manufacturer of an EXPERIMENTAL aircraft is our responsibility to verify the suitability of all construction materials, processes, etc. When Saf-T-Poxy was removed from the market we had to find a substitute. Either we could accept someone elses evaluation of the suitability of the replacement or we could do our own testing. I know that scrapping a major portion of an airplane because the materials prove to be un-airworthy would come very close ruining a good day-week-year-years but it was our responsibility to verify the suitibility of the materials in the first place. Now if the airplane was purchased as a complete kit from a manufacturer then a diffferent situation exists but with the Cozy this isn't the case. One of the main reasons for choosing the Cozy is that you have the opporitunity (responsibility) to choose the source and suppliers for the various component parts. This may very well qualify for a class action law suit but remember, that is what killed the general aviation industry. All of this is just a caution. It is very easy to whip a situation up into a frenzy on the internet. If it is the concensus of the group that it is someone elses responsibility to verify the suitability of our construction materials then I think that a dangerous trend is developing. I don't think Scaled would consider changing construction materials without personally verifying, through exaustive testing, that the replacement materials were acceptable. A complete aircraft is a rather expensive engineering sample to use for your suitability testing experiments. Again IMHO Steve Eberhart newtech@newtech.com Just a lurker but couldn't keep quiet on this one. From: "John R. Rogers" Subject: Re: COZY: 2427 EPOXY LIABILITY Date: Thu, 24 Oct 1996 10:04:08 -0500 Steve, Do you really want to bring the lawyers into this??? Many manufactures are so lawsuit shy they won't even sell their products to be used for general aviation. At best we are seeing conflicting reports on 2427. If you believe there is a problem, don't use it. Pretty simple really. Talk to the experts, talk to the suppliers, talk to the manufacturers. Talking to the lawyers is most cases only satisfies the lawyers... John > From: SBLANKDDS@aol.com > Question: What is the liability of the supplier and or manufacuter? I have > about $275 in my canard plus my unrecoverable time. Any lawyers in the > group? Do we have a class action? Was this manufactured for this use? Do > we have any recourse as a group? > > P.S. I have one unopened gallon kit of the 2427 stuff for sale (or a good > home). NOT for aircraft use!!!! > > Steve Blank, Cozy Mark IV#36 Port St. Lucie, FL USA sblankdds@aol.com > Date: Thu, 24 Oct 1996 11:50:27 -0400 From: Jim Hocut Subject: COZY: Gougeon Bros. Pro-Set ? I've been hearing about Gougeon Bros. Pro-Set for a little while now. Anyone know where it's available? Anyone have experience with it? I've also tried Poly-Epoxy and like it pretty well. It's a 2-phase epoxy, and as such should be stronger than single phase systems. Layups seem to be "tougher" (a purely subjective observation, no data to back this up). (BTW, I've been using 2427 extensively and have had no problems with it at all. I do, however, have an air conditioned shop so that I wouldn't experience any of the humidity related problems). Thanks, Jim Hocut jhocut@mindspring.com by Npt.NUWC.Navy.Mil (PMDF V5.0-5 #13155) id <01IB0R8LXSP694DURD@Npt.NUWC.Navy.Mil> for cozy_builders@hpwarhw.an.hp.com; Thu, 24 Oct 1996 12:12:01 -0400 (EDT) (4.1/SMI-4.1) id AA12029; Thu, 24 Oct 1996 12:12:39 -0400 (EDT) Date: Thu, 24 Oct 1996 12:12:39 -0400 (EDT) From: triley@c38fs0.npt.nuwc.navy.mil (Tom Riley) Subject: COZY: 2427 epoxy Hello all, I just want to mention that my intent in warning everyone about the problems I experienced with delaminations of 2427 layups was to awaken other builders to this possible hazard. I say "awaken", 'cause that's what I would say happened to me, and I could see it happening to others. I read all the past emails about 2427 problems and just let them roll off my back. I think it's a combination of two states of mind that were tugging at me. First, there's the attitude that "there's nothing wrong with my plane --- I've been building it right." Second, I didn't want to admit that there could be a meatrials problem, 'cause this could mean months of wasted work. As I mentioned in my first posting, I saw the problem a long time ago and basically stuck my head in the sand and chose to ignore it. Since then I've seen evidence of it several times and I still didn't want to beleive it until it finally reared up and kicked me in the butt. I AM TO BLAME FOR MY OWN ACTIONS. I should have been more suspicious of materials and tested them to my satis- faction as soon as there was the slightest doubt. Had I done this, I would have saved myself a lot of rework that's now facing me. I know there are some of you who have successfully built parts using 2427. I think I was one of them, initially. Some of my early parts appear to be O.K. But the stuff obviously has some problems and I don't think it's worth the risk of either flying with something that's eventually going to fall apart or having to repeat months of work already expended. Recent talk about lawsuits were the very last thing I ever wanted to promote. I have very strong feelings about liability lawsuits and they're all negative. The end result of a class action suit would be that the lawyers get all of Hexcell/Fuller's money and we end up killing our own hobby. Let's stop this kind of thinking right now. As for my losses, I screwed up and I'll accept responsibility for my own actions. All I ask is that those of you who have been using 2427 please go back and satisfy yourself that everything is O.K. by trying to tear apart some scraps or easily repairable inconspicuous parts of your airplane. One person reported that he peeled the BID tapes off the seatback after they had cured and did them over. I'd want to know if it's now possible to peel them off again. I did my BID reinforcing tapes in SafetyPoxy and there's NO WAY I can peel them off. You would have to chissel them off a 1/4" at a time, as it should be. I've heard statements like "the peel strength was tested and is acceptable". I may be wrong, but I would think that ANY capability of peeling a composite structure apart is UNACCEPTABLE. I base this on my limited experience with SafetyPoxy. There was no way I could peel any of that stuff apart. It could only be chisseled apart in very small pieces with considerable effort. Don't do like I did and stick your head in the sand. Tom Riley From: Epplin_John_A@hpmail1.90.deere.com Date: Thu, 24 Oct 96 11:23:56 -0500 Subject: COZY: 2427 epoxy Having followed this story the last few days prompted me to double check my work completed at this point. Have canard assembly completed, fuselage tub up to nose cone, main gear tabs and torque layers and carry-through spar about half finished. I took a scrap of the 1/4 in. thick laminate used in the gear attach bulkheads and de-lamed it with a sharp chisel. It came apart somewhat easier than I had expected with a sharp chisel as long as I removed several layers. I could not remove a single layer, the glass would fail before it peeled apart. I found the scrap I removed for the canard cutout and picked at it in several ways. The only way I could easily de-laminate any part was where there was obviously insufficient epoxy, not any way near fully wetted out. I could start to peel cloth from the edge that was completely dry but when I reached the area that was saturated, the cloth would fail. Forcefully removing any glass from the foam removed bits of foam and micro. I inspected the fuse. tub reinforcing tapes again. A small area over the center seat belt attach tube had an edge that I intend to sand off. I attempted to start at this edge and delaminate the reinforcement. I did not want to destroy any thing needlessly and gave up after considerable force with a knife. What I am saying is that I cannot fault the material or methods used up to this point. I made all the lay-ups in my basement during the winter, starting early Oct. last year and quitting end of May this year in order to build a separate shop to finish in. I am about to resume Cozy project again, just a little interior paining to go to finish the new shop. 24 x 36 ft with 10 ft ceiling, heat and everything. The lay-ups were done at 75 deg. F with for the most part rather low humidity, probably less than 20%. The epoxy materiel was kept at 100 deg. F and measured with an AccuLab scale. No more tha 150 grams were mixed at a time and any that had thickened somewhat was discarded. All mixing was done in Dixie hot cups (no wax). Foam was vacuumed, areas of cured glass were always peel plied and wiped with acetone before next layer attached. If any doubt about surface, light sanding was done. John Epplin, Cozy Mk 4 #467, A&P 1471047 Date: Thu, 24 Oct 1996 10:49:50 -0700 From: berkut@loop.com Subject: Re: COZY: Gougeon Bros. Pro-Set ? >I've been hearing about Gougeon Bros. Pro-Set for a little while now. >Anyone know where it's available? Anyone have experience with it? You can get it from Svendson Marine in Alameda, CA (510) 522-7860. We use the 125 resin and the 229 hardiner - it's tough, wets out terrifically, VERY strong. Scaled uses it for almost everything now. Date: Thu, 24 Oct 1996 15:08:08 -0400 From: AlWick@aol.com Subject: Re: COZY: 2427 epoxy In a message dated 96-10-24 12:17:05 EDT, you write: <> Hey Tom, I just want to say thanks. I'm not done looking into my adhesion issue, but probably would not have without your input. THANKS. In particular thanks from that guy that hasn't started building structural components yet. << I AM TO BLAME FOR MY OWN ACTIONS.>> Hold on here. What planet are you from? :-) It's easy for a reader to assume that this is all a workmanship issue. Hopefully your input will help them realize that the epoxy is not as robust as it needs to be. -al From: Nick Parkyn Subject: RE: COZY: 2427 EPOXY LIABILITY - What is the real problem! Date: Thu, 24 Oct 1996 15:17:05 +-1000 The definition of the problem seems to be inter-laminar bond strength - = which affects peel strength. This normally indicates poor preparation or = contaminated bond surfaces. While it seems from what has been written, = that the Cozy builders have taken great care, you need to determine = separately the properties of the resin and a laminate. There were = similar problems at one time in the marine composites industry with = other brands of resin, which was eventually traced to a surface = treatment that was being used on some "no name brand" peel ply which was = contaminating the bond surfaces. What you need to do is to determine separately: 1.) the properties of the resin by making a casting and testing it for = hardness and other properties and comparing these with those advertised = by the manufacturer. 2.) the properties of laminates that has been fabricated from RA UNI in = one layup and compare these tests with the figures for a similar layup = that used the original Hexcel product. Rutan Aircraft would have those = figures. (tensile, compressive and peel tests could be done).=20 =20 The above test samples would have to be fabricated under documented = conditions, with temperature, humidity etc recorded. Accurate = resin/hardener mixing ratios within say 2% of those indicated by the = manufacturer would need to be guaranteed. If either of the above tests = fails it would suggest that the resin is at fault, if not it is surface = contamination by something including possibly the peel ply.=20 There are a number of companies that could do the testing. Possibly it = could be done (through Nat) at Rutan Aircraft / Scaled Composites they = have all the test gear! You need to reduce the variables and test systematically and accurately = - the onus on you is to prove beyond doubt that the resin mixed and used = in accordance with the instructions does not meet the specifications! =20 ---------- From: SBLANKDDS@aol.com[SMTP:SBLANKDDS@aol.com] Sent: Thursday, October 24, 1996 10:16 AM To: cozy_builders@hpwarhw.an.hp.com Subject: COZY: 2427 EPOXY LIABILITY > This in response to Tom Riley and others like me that believe that = our work is not the problem, but that the 2427 is providing inadequate = bonding between structural layers. Even if some parts look good, how do I know that the internal spar is = good? I don't. I believe this stuff is defective and should not be used in aircrafts. = It may be a high humidity problem. I don't know. But that 2427 stuff is = not nearly as cohesive as safe-t-poxy or EZ10 resin in my garage. Question: What is the liability of the supplier and or manufacuter? I = have about $275 in my canard plus my unrecoverable time. Any lawyers in the group? Do we have a class action? Was this manufactured for this use? = Do we have any recourse as a group? P.S. I have one unopened gallon kit of the 2427 stuff for sale (or a = good home). NOT for aircraft use!!!! Steve Blank, Cozy Mark IV#36 Port St. Lucie, FL USA = sblankdds@aol.com Date: Thu, 24 Oct 1996 20:09:51 -0700 From: Chris van Hoof Organization: C van Hoof - Architect Subject: COZY: 2427 thanx Hi cozites, Thanx to all participants on the 2427 debate. Having recently ordered some 2427 from a/c spruce (which i'm now trying to cancel) the question remains - HAS ANYBODY SEEN A SPECIFICATION SHEET ON THIS STUFF - and could you let us all have insight on this please.(big _please_ :-)) This will help us to determine the intended strenghts/etc of the product, how will we know what its designed strenghts etc are/were and even what we are testing for (over and above finding the total/ultimate product limitations.) And if you want me to contribute towards a lawyers fund - COUNT ME OUT - Chris with Cozy #219 in chapter 8 cvh@iafrica.com From: Nick Parkyn Subject: COZY: Testing of resin & laminates - some guidelines Date: Fri, 25 Oct 1996 09:55:44 +-1000 Most fabricators of composite structures even in the marine world at = least retain, date and test cured resin samples for all structural = layups. These resin samples are tested for hardness and compared with = the manufacturers specifications to ensure that the resin cured = correctly. Hardness testers can be purchased from suppliers of material test = equipment, while they are not that cheap, this testing will give you = some "peace of mind" and quality control.=20 Composite fabrication is all about quality control! If you are going to use a resin which is not "approved", prepare a = laminate "in your own garage" using RA glass fabrics test it and = compare the results with value achievable with the approved resins. = These same test would have to be done after immersing the same laminate = in aviation fuel for a period of at least 3 months. If the properties = exceed those of the approved resin it is a bonus, if they do not, then = don't use it! This testing can be done with the simple test machine - = for details see the book Composite Basics by Andrew Marshall.- see = advert in Sport Aviation. BE CAREFUL WHEN SELECTING A NON-APPROVED RESIN AS MANY RESINS ARE NOT = AVIATION FUEL RESISTANT.=20 A rough comparison of resins can be done by comparing the average of the = tensile and compressive moduli of the resin - data provided in the = specifications sheets. This may vary in a particular resin system with = different hardeners so be sure to get the specifications for the exact = resin / hardener combination that you will be using. Compare this figure = with the approved resins. Surface finishes on some "fabric shop" peel ply has been known to = contaminate peel plied bond areas. DO NOT TRUST PEEL PLIED SURFACES = unless you have done tests. If you change your peel ply - test again!=20 Date: Fri, 25 Oct 1996 19:17:39 -0400 From: SBLANKDDS@aol.com Subject: COZY: Canard Testing 2427 resin If some one would like to test my canard built with 2427 to destruction, I would donate it to the cause. I have no test apparatus to do this. I got the message from all of you about the lawyer thing... I was just angry, but now i am mostly curious. Forget the lawyer thing. I didn't really say it did i? oops.. sorrry :( I wonder just how good my layups are and the bond strength of the resin. I have too many doubts to finish this plane and put my family in it with this resin on such a critical part as the canard. I'm sure I could build a second canard faster and better anyway. Perhaps those built in lower humidity areas are just fine. My humidity in south Florida hovers around 80-100% year round. This warning may not apply to all users of 2427. Test for yourself. I CAN EASILY SEPARATE THE LAYERS OF GLASS ON THE BOTTOM OF THE ELEVATOR WITHOUT TEARING A FIBER!!! In addition, I can lift up the first layer, and it separates easily from the micro layer. The micro bond to the foam seems better than the glass to the micro layer. The micro was put on wet, and then the glass applied with no delay. I did NOT hardshell or do anything else creative. I am not sure if this is a problem. There may not be any forces in flight that would cause this separation. I am NOT able to do this to any of my Safe-t-Poxy layups, or EZ-10 Layups. My test layup of two plies of BID (2427) on either side of a 1/4" foam seems good!!!???? I took everyone's advice and made more test pieces using the EZ-10. Everyone should do this, often. Use a scrap or two when doing real work, put a few layers on, then try to destroy one piece. I can not determine if their was a diference in technique or a change in resin quality with time, or humidity. I will have some local EZ flyers inspect my work and report back later. Less e-mail more work. Thanks for listening. Steve Blank Cozy Mark IV #36 Port St. Lucie,FL (561) 337-3377 Date: Fri, 25 Oct 1996 22:02:41 -0700 From: Eric Westland Subject: COZY: 2427/Fuel? Cont... I received a call from Valerie Harris this afternoon in response to the letter I had written her and her husband asking for additional information. I was concerned after reading the article they had submitted to the CSA newsletter on 2427 and 100LL fuel. When we were done talking, I asked her if I could pass on what we had discussed to you all and she told me that would be fine. Here is what I learned. They bought Merle Musson's project, re-built it and had it back in the air last October. Later that spring (7 or 8 months after it was flying again), when they suspected one tank might not be flowing as well as another, Valerie conducted a fuel flow test and checked all the lines/vents as well as the gascolator. All was well. Five flight hours later, the engine stopped in-flight resulting in the previously mentioned accident. Robert walked away with minor injuries. The wreckage was hauled away to a hanger for investigation and fuel samples were taken and set aside in clear glass jars. The fuel samples appeared fine. When the gascolator was inspected, the screen was completely choked off with flakes that looked like "small dandruff". In the meantime, it was noticed that the jars of fuel had sediment on the bottom of them, made up of the same small flakes. When the jar was shaken, the fuel appeared "clear" again. It was their insurance company that sent the strake samples to a lab for a report and then their insurance agent that called them with the results. They were not given a copy of the lab report. That's about it. I have tried to stay true to what Valerie said - she was very open and willing to answer whatever I asked. At the same time, in fairness to the Harris's it should be mentioned that once the wreckage got hauled off, determining what happened was pretty much out of their hands and in the hands of the investigators. I appreciated her taking the time to call me and her offer to call her again if I had further questions. I think it would be fair to say you could do the same if you felt the need. I know this posting does not clear up the 2427/fuel compatability question, but I wanted to pass on further details to those of you at or beyond my building stage that are in the "2427/fuel boat" and wondering what to do. At the same time, if I have been less than clear (it wouldn't be the first time), please ask for a clarification - you know where to find me :-). -eric Date: Sat, 26 Oct 1996 10:25:49 -0500 From: Neil Clayton Subject: COZY: Sick, and mad as hell!!! I've been reading the dialogue about 2427, but considered myself immune. How could my layups be anything but perfect??? I idly probed around the fuse side with a sharp knife and a layer peeled off easier than I ever expected. Suddening getting serious about it, I conducted a more in depth inspection and discovered the fuse is pretty much a write-off. My 4 month-old daughter probably has enough strength to peel away layers at some places. This weekend the entire plane gets an inch-by-inch inspection. When I think of all the careful hours of work....! Hexcel are going to get a new irrate customer come monday AM! F&$@*#^ 2427 junk! Date: Sat, 26 Oct 1996 09:49:41 -0700 From: Michael Antares Subject: COZY: Epoxy problems Just to provide a comparison for evaluation, I have been using RAE epoxy from the beginning. The first test I did was a year or so ago while still building the bulkheads. Remember the 22 layer hardpoints for the landing gear? I had some leftover pieces after cutting the hardpoints out of the layup I had made. Two pieces were a couple of inches wide by 6-8 inches long. I clamped one end of a piece in my large vise and then took a hammer and struck the other end as hard as I could. The hammer bounced off the fiberglass and there was just a small area of delamination at the vise jaw edge. I then took the same piece into work to show a friend and he mounted it in a large vise and hit it with a 3 pound dead hammer as hard as he could. The piece bent at about a thirty degree angle and showed about a half inch of delamination at the vise jaw edge but did not break nor could it be bent by hand even with the delaminated area! There is no way I can separate layers, in fact it is almost impossible to delineate a layer. A multilayer layup acts as a homogeneous block--as some people have suggested it is much like G10 printed circuit board material for those of you who are familiar with the material; these are the green circuit boards like in your computer. I feel a deep sympathy for those builders who are experiencing problems with the 2427. I didn't choose RAE because I knew anything about it when I started the project. The specs indicated that it had a wider working temperature range than other epoxies and because I am building in a very old garage it is impossible to get the temperature into the 70's during the winter. I thought I would try it and if I got an allergic reaction I would shift to something else. So it was serendipity more than anything else that caused me to use the RAE epoxy. I thank the Gods that guide us who are stupid! In over a year and a half now of using the RAE I haven't had any adverse reaction so it seems to have been a good choice all around. Michael 6077 Old Redwood Highway Penngrove CA 94951 707.664.1171 Cozy#413 Finished through chap 14 except chap 13. Chaps 16 & 24 mostly finished. Now on chap 19, one wing finished. Date: Sat, 26 Oct 1996 18:32:47 -0400 From: SBLANKDDS@aol.com Subject: COZY: 2427 Data Collection This is in response to my problems with 2427 resin and Neil Clayton's fuselage. I just recieved an e-mail suggestion to try post curing parts. The bond strength supposedly goes up. I am waiting for e-mail with specifics about what temperatures for which foam, and how long the temp has to be maintained. Then I will restest my scrap pieces and my elevator that is know defective. Don't throw out your fuselage just yet.... Any one else having 2427 peel strength problems send me the honest answers to the following questions and I will report the data back to the group. Lets get to the bottom (layer) of this soon! I will not use your names if you wish to remain anonynous. This will reduce the quantity of e-mail and make the data easier to view as a whole. 1. Where do you live? (desert, mountains, coastal, plains) 2. What is the humidity like? 3. What was temperature (farenheit) when you worked on the defective part? 3. Did you do any layups when it was raining? 4. Did you let any layers cure partially or completely before laying the next layer on? (was the resin getting thick or jelly like?) 5. Did you hardshell? 6. Was you micro layer dry and very thin or wet and thick. Did you get excess micro between layers? (did the cloth wet out with micro before you added any epoxy? 7. Are you layups too dry? 8. Did you peel ply everything, or just edges? 9. Did you wait for complete cure before removing peel ply? 10. Did you use a hair dryer to thin thin the resin when working? 11. Did you past cure the part? (what temp and how long) It would be great to find the source of our problems. It may help some people feel better while alerting others to potential problems. I know my work is good. My only weakness has been a few slightly dry spots. The same dry areas of Safe-t-poxy 2 can not peel. Perhaps I have been too weight conscious, now I will be strength conscious.... I just did test layups using EZ-10 resin that I purchased from Jeff Russell - Aerocad. It is very much like S-T-Poxy 2. Color is slightly lighter, and more translucent. Wets out easier than S-T-Poxy2. All tests seem good. No peeling!!! Best wishes to all frustrated 2427 resin mixers. Hopefully we will find a fix so our time isn't wasted. E-Mail me at: sblankdds@aol.com Steve Blank Cozy Mark IV #36 Port St. Lucie, FL USA Date: Sun, 27 Oct 1996 14:21:15 -0800 From: Chris van Hoof Organization: C van Hoof - Architect Subject: COZY: Epoxy testing Hello to all, We in the sunny South Africa are presently experiencing the beginnings of our summer. This means (in Johannesburg) hot days with the temps mostly around the 22C (72F) up to 28C (84F) with the humidity at 50% to 80%. During the summer months you can set your watch on it - the rain pours around 3 or 4 pm. Our elevation is around 5000'. At present we are gathering various makes of Epoxy samples, with the intention of doing comparative tests. The idea is to do some type of home-test system on all types at the same time, same day and therefore the same conditions - all this of course with my fellow members at chapter 322. Here is what we've got : we have at present 6 types of epoxy systems (incl 2427 Epolite)- 8oz each we have UNI and BID in my workshop and will use the same layup on each we have enough blue foam to do a test on each if required we thought to make (say) 3 samples each on mylar and peelply half of the top we thought to post (oven) cure one of each sample and test same So much for the contents - NOW - Someone with experience - advise us how to do this sort of testing without going over the top. By that I mean tests must be able to be conducted in a well appointed garage not a laboratory. We have a lot of inhouse (322 chapter) knowledge but since this is started by the Cozy builders forum, I am asking you for advice on this matter. Looking forward to your replies. Chris with Cozy #219 in chapter 8 cvh@iafrica.com Date: Mon, 28 Oct 1996 10:35:43 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: COZY: 2427 Data Collection Steve Blank Wrote: >I just did test layups using EZ-10 resin that I purchased from >Jeff Russell - Aerocad. It is very much like S-T-Poxy 2. Color is >slightly lighter, and more translucent. Wets out easier than >S-T-Poxy2. All tests seem good. No peeling!!! This is what I told you people about having problems in our shop with most of the other resins manufactured with high amounts of amines. The styrene that is added in the EZ83,84,87 hardeners will NOT have problems with water. We have seen water problems with ALL the amine base systems. Hexcel's RAE 2426 resin & 2176, 2177 hardeners (Red for fast, Blue for slow) Hexcel's EPOLITE 2410 resin & 2183, 2184, 2187 hardeners (Light to dark brown) Hexcel's EPOLITE 2318 resin & 2316 hardener (clear) Hexcel's 2427 resin & hardener (clear to light amber) CPD's replacement EZ24 resin & EZ83,84,87 hardeners (Dark yellow) Garfield asked >O.K. here are my questions: >1. If 2426 is the old RAE stuff, which is reported to be brownish >or bluish green (depending on hardener used?), if Wicks is going to >carry it again, who is the manufacturer now & is the color the same as >the old, (if not what is the distinctive color?). Jeff's post above >seems to suggest that the old RAE/2426 stuff WAS amine based; is the new >reissue of 2426 subject to amine humidity problems or not? Was the >old? 2426 will still have humidity problems >2. Which of the above systems mentioned by Jeff is the numbers for >what used to be SafeTPoxy I (and II)? And did the old SafeTPoxy I >contain Styrene & MDA? I thought SP II removed these components. SafeTPoxy I 2410/2183 or EZ10/EZ83 contain Styrene & MDA SafeTPoxy II 2410/2184 or EZ10/EZ84 contain Styrene & MDA We sell the EZ10/EZ84 system in 2 gal kits for $130.00 + shipping. AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 phone/fax 910-961-2238 E-mail: JRaerocad@gnn.com NEW homepage address: http://www.binary.net/aerocad Date: Mon, 28 Oct 1996 15:56:34 -0500 From: DFinn7971@aol.com Subject: Re: COZY: Epoxy problems In a message dated 96-10-26 12:03:42 EST, mantares@a.crl.com (Michael Antares) writes: << I feel a deep sympathy for those builders who are experiencing problems with the 2427. I didn't choose RAE because I knew anything about it when I started the project. >> As with Mike, I have been using RAE on my project. It is getting mildly harder to obtain now the Hexcel is out of the business but is still available from Wicks at about $10 to $15 more per gallon then when I started five years ago. I just bought enough (I hope) at OSH this Summer to finish my project. I count myself lucky that I chose RAE and that I have not yet shown any signs of an allergic reaction. My method of selection was rather simplistic as I knew absolutely nothing about epoxy. I found out that the R in RAE stood for Rutan. Rutan designed the plane, therefore RAE was the way to go. Not too scientific I'm afraid -- another example of God looking after the feeble minded. After all the talk on failed layups I took hammer and chisel to some of my scraps over the weekend. Like Mike, I picked some leftovers from the 22 ply landing gear layup. I was able to cut through it but the chisel actually was cutting through the glass fibers at an angle. I was unable to actually delaminate any plys. All in all it seems to be pretty good stuff. My project has been a labor of love for five years and I can't even imagine how bad I would feel about loosing it. Like Mike I feel a deep sympathy for anyone who is experiencing problems. I would feel a whole lot more sympathy for their widows however if they were to continue on only to have the plane fail in flight. My personal believe is that anyone using the 2427 should seriously consider redoing any structural parts with RAE or Safty-poxy. If any of you who are experiencing problems are in the Chicago area please feel free to call on me for help in getting back up to speed with another epoxy. I'd be happy to come over on a regular basis and help you rebuild parts. The danger with setbacks like this is that builders could become discouraged and just junk the whole thing. I think we all need to get behind anyone who decides to rebuild parts and offer help and encouragement. Dick Finn Cozy mark IV #46 DFINN7971@AOL.COM by SERV05.SLAC.STANFORD.EDU (PMDF V5.0-6 #10979) id <01IB6H0YWF8U000KZC@SERV05.SLAC.STANFORD.EDU>; Mon, 28 Oct 1996 14:24:20 -0800 (PST) Date: Mon, 28 Oct 1996 14:24:24 -0700 From: hrogers@SLAC.Stanford.EDU (Howard Rogers) Subject: Re: COZY: Gougeon Bros. Pro-Set ? >>I've been hearing about Gougeon Bros. Pro-Set for a little while now. >>Anyone know where it's available? Anyone have experience with it? > >You can get it from Svendson Marine in Alameda, CA (510) 522-7860. We use >the 125 resin and the 229 hardiner - it's tough, wets out terrifically, VERY >strong. Scaled uses it for almost everything now. I called these folks, as I work right accross the bay from them. They quoted me well in excess of $100 for a kit of 1 gal of resin plus hardener. Can this stuff be had cheaper, somewhere else? How do you know that Scaled is using this stuff? Do you think Burt Rutan would approve its use as a replacement for the Safe-T-Poxy/Epolite? To your knowledge, has he spoken out on this subject? What are you using Pro Set for? How did you satisfy yourself that it was adequate for your purposes? A little history, please. Howard Rogers, A&P 2005148 Date: Mon, 28 Oct 1996 16:30:34 -0800 From: berkut@loop.com Subject: Re: COZY: Gougeon Bros. Pro-Set ? >>>I've been hearing about Gougeon Bros. Pro-Set for a little while now. >>>Anyone know where it's available? Anyone have experience with it? >> >>You can get it from Svendson Marine in Alameda, CA (510) 522-7860. We use >>the 125 resin and the 229 hardiner - it's tough, wets out terrifically, VERY >>strong. Scaled uses it for almost everything now. > >I called these folks, as I work right accross the bay from them. They >quoted me well in excess of $100 for a kit of 1 gal of resin plus hardener. >Can this stuff be had cheaper, somewhere else? No, that's how much it is. >How do you know that >Scaled is using this stuff? Mike Mellville told me. And when I ran out and needed 10 gallons in a hurry a few weeks ago, they were kind enough to sell me some (only because I was desperate, I wouldn't ask normally) >Do you think Burt Rutan would approve its use >as a replacement for the Safe-T-Poxy/Epolite? >To your knowledge, has he >spoken out on this subject? I wouldn't want to second guess Burt. But it's the primary resin that they are using these days. He went to it after Hexcel withdrew 2140/2183 and family. >What are you using Pro Set for? Molding Berkut and other parts, general structual assembling. >How did you satisfy yourself that it was adequate for your purposes? A little history, please. Tested it for handling, double checked the mechanicals the Gougeon provided. Rippped apart some test pieces. From: Lee Devlin Subject: Re: COZY: Epoxy problems Date: Mon, 28 Oct 1996 17:43:23 MST Dick wrote: > My personal believe is that anyone using the 2427 should > seriously consider redoing any structural parts with RAE or Safty-poxy. [Since all parts are structural to some degree, I interpret this advice as: throw out all of your work if it was done with 2427] I was hoping that this topic wouldn't degenerate into any hysterical suggestions, but alas, I feel it has. There are those of us in dry climates (or in humidity-controlled workshops) who are using 2427 quite successfully with no delamination problems. I've run the peel tests on every part I could find and could get *no* delamination to occur. Remember, the 2427 epoxy was tested and given an official blessing by RAF. RAF is located in Mojave, CA so anything they test will most likely _not_ be tested for its potential for degradation in a humid curing environment. As for Gougen Bros. Proset, it could very well have the same problems with humidity as 2427. (Jeff's recent posting seemed to indicate that virtually every epoxy we use is affected by humidity.) Another possibility which we haven't really considered is that Hexcel's process went awry and produced some bad batches of 2427. Maybe we should collect the batch numbers from those who have experienced the delamination and see if there's a clue there. Before we jump to conclusions about the structural integrity of all parts made with 2427, it would be wise first to do a peel test on your parts and see if you have the problem or not. If that still doesn't satisfy you, you can load the part statically and see if it collapses like a house of cards. Judging by the descriptions of the problem, the strength of the bonds are so severely compromised that if you loaded the part to about 20% of its design load it would disintegrate. Please pardon my highly offensive writing style, Marc tells me I'm actually polite in person. :-) Lee Devlin | HP Greeley Division | Long EZ N36MX Piper Colt N4986Z | 700 71st Ave. | Cozy MK IV under const. 'Spirit of rec.aviation'| Greeley, CO 80634 | (Chapter 10) Date: Mon, 28 Oct 1996 22:00:12 -0500 From: Mahan Subject: Re: COZY: Gougeon Bros. Pro-Set ? Howard Rogers wrote: Do you think Burt Rutan would approve its use as a replacement for the Safe-T-Poxy/Epolite? To your knowledge, has he spoken out on this subject? I looked through my back Canard pusher issues, and can't find anywhere where Rutan/RAF/Scaled recommends Pro-Set for the homebuilder. The July Canard Pusher refers the reader to the discussion of E-Z poxy in the Central States Newsletter, and the April issue also discussed E-Z poxy at length, without specifically recommending it. Fred in Florida Date: Mon, 28 Oct 1996 23:19:39 -0700 (MST) From: Roy Grossinger Subject: Re: COZY: Epoxy Choices I'll buy the epoxy if you want to change. I haven't had any of the troubles aforementioned, but that is skewed by two conditions. 1) Colorado has low humidity, lower with forced air heat 2) Vacuum bagging seems to avoid pre/post cure troubles Roy H. Grossinger- ME grossinr@rastro.colorado.edu Cozy Mk IV #503; Chapter 7 ROY_GROSSINGER@Radon-hq.ccmail.compuserve.com Date: Mon, 28 Oct 1996 23:52:55 -0800 From: Paul Comte Subject: COZY: Epoxy Choices Well Ladies and Gentlemen I'm at the horns of a decision. On the last day of Oshkosh 96 I made what I thought was a great buy. I bought ALL the materials to complete the Cozy MKIV fuselage. Of course this included the Hexcel epoxy. Now after reading the last 200 or so postings I'm not sure I'm starting with the best materials. I am finishing my workshop now in a (improved to be dry) dry basement in Milwaukee, WI. (a concrete sealer "Vulcan" and grading works wonders!) So if you were me, would you you go with the materials I've bought and paid for OR would you scrap the Hexcel and buy something else? It might be helpful to all if we gather a measurement of support for the Hexcel product. I'll tally private responses (to me) and report back to the group by the end of the week. Address the mail yes, no or no comment. I'll post the totals on November 3rd. For responses with dialog speak to the group as well. Yikes, did I just ask for a pile of e-mail? well yes I did! Paul Comte pcomte@tcccom.net sn246 Cozy MKIV, MKE Date: Tue, 29 Oct 1996 08:26:19 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: COZY: 2427 Data Collection Jeff Russell wrote: > >We sell the EZ10/EZ84 system in 2 gal kits for $130.00 + shipping. > Fred in Florida wrote: >I'm a little confused, 'cause I usually see kits quoted based on 1 >1/2 gal.: 1 gal. resin and 1/2 gal. hardener. What is in your 2 gal. >kit? I am getting ready to do some layup work on my Defiant project and >need E-Z poxy. Any rough idea what the shipping would be to Florida? >I built my Long-EZ here in Florida using Safe-T-Poxy and the > original Epolite. I'd prefer the EZ83 hardener. Do you handle it? 2 gal kits = 16 lbs EZ84 resin and 7 lbs EZ84 hardener. we only stock 84 hardener. Shipping to florida for this will be $8.40 AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 phone/fax 910-961-2238 E-mail: JRaerocad@gnn.com NEW homepage address: http://www.binary.net/aerocad by Npt.NUWC.Navy.Mil (PMDF V5.0-7 #13155) id <01IB7O7CUL2Y94DNP5@Npt.NUWC.Navy.Mil> for cozy_builders@hpwarhw.an.hp.com; Tue, 29 Oct 1996 11:00:18 -0400 (EDT) (4.1/SMI-4.1) id AA28732; Tue, 29 Oct 1996 10:59:37 -0500 (EST) Date: Tue, 29 Oct 1996 10:59:37 -0500 (EST) From: triley@c38fs0.npt.nuwc.navy.mil (Tom Riley) Subject: Re: COZY: 2427 epoxy -Reply Rego Burger wrote: >Hi Tom, > >From South Africa > >Listen thanks for the warning. I'm doing tests on my batch here too! Hi Rego, Thanks for your inputs. Since some of my first postings on this issue, I have determined that all of my problems can be attributed to a single batch of 2427, which carried the H.B. Fuller label. All other previous work using Hexcell 2427 are sound. I don't know if it was a "bad batch" or it was contaminated by humidity, CO2, etc., etc., but it appears that its cured properties were bad from the moment I started using it. But, I started using that batch just as the humid summer came in, so I can't be certain if it was the batch or the humidity. In any case, I will now test the cured properties of any new can of epoxy before using it (as I should have done in the first place). I still lost a lot of time and materials as a result of that "bad batch", and I'm now in the process of stripping my landing gear. I was going to try to remove just those areas of the torsional layup that are easily peeled and repair as required. I can't seem to find any sound layers. I'm concerned that the constant workout it will get from landings will delam the whole thing in time, so I think I'm going to go down to the bare glass gear for peace of mind. The rest of the layups (landing gear bulkhead reinforcements, heat duct, seatbelt reinforcements, shoulder support, etc.) are all poor in strength, but useable. I've also committed to using the old standby RAE epoxy, have since received two, one gallon kits and I just put a sample together to try it out. Although it was just a small test swatch consisting of three layers of BID, I did like the initial properties ... no objectionable odor and it wets out very easily. If I don't have an alergic reaction to it, I think I've found the solution to my problems. In conversations with several who have consistently used RAE, they report that it is very insensitive to environment, batch age and marathon layups. That's what I want. Again, thanks for your feedback and I'll keep you posted if I learn anything more on the subject. Tom Riley, MKIV S/N 113 Date: Tue, 29 Oct 1996 11:19:17 -0800 From: Chris van Hoof Organization: C van Hoof - Architect Subject: COZY: Epoxy test 2 Hi there, regarding comparative tests - thanx for all the input/advice So far have managed to aquire: Pro-set - 125 resin with 229 hardner 2427 Epolite Jeffco - used in lancair Saf T pox Reapox - made by Rea Industries (French) 2022 - Axson (used to be Hexcel France) 2023 - do (but longer potlife +- 3hrs and for use in high Humidity areas) and in the meantime have found out that its a quagmire i'm entering regarding humidity - we have heavy rain every day but my hygrometer measures 65% during the heaviest downpour - so i checked the neighbour's and his measured 62% - also remembered never having seen more than 90% on the unit after having set it according to the instructions - that was while on holiday at the sea....so how do i replicate high humidity without adding water directly in the mix? (in my garage)(also I dont have a Sauna :-)). regarding 2427 Epolite - Rego Burger lives in Port Elizabeth at our East coast and reports that short of a few (the odd) bubbles his layup appears OK - but they don't have the Florida (USA) type humidity - Rego is on the forum - maybe he'll comment direct. regarding layup - each to make sure that we dont overdo it - when Rutan says "not white not wet" is easily taken past the meaning, depending on the individual. this I noticed from comments during layup inspections on my project..ie " I like your layup to be rich without running droplets" also " don't starve the layup untill you disturb the lower layers" ( I invited these "inspectors" to criticize my work in the early stages so as to establish a standard for myself. The inspectors are Approved Persons - Thats our system of delegating by our DCA (our FAA)). regarding Aircraft Approved Epoxy... We (in South Africa) have a department (partly gov funded i think) called the CSIR (Council for Scientific & Industrial Research) ... where I found a very helpfull individual named Chris Adriaan who told me that they have done extensive testing on the Hexcel 2022 system as well as Ceiba-Geigy 5052 system - the tests included interlaminal shear test etc etc....both are Aircraft Approved... the 2022 is better suited to homebuilt (DIY) than the other...I'm using the 2022 at this moment (and its great). These tests are available for public insight (I understood) but are almost like a presentation for a Doctorate ( It really takes Experts to confuse the answer, doesn't it? :-)) ...Anyway helpfull he was and even offered to do the tests in the lab, after we had made the samples, AT NO COST, how's that for support?!!! Futher to the above: We are also planning to do some non scientific tests, such as adding a layer of peelply, cure and adding some more. (suggestion by cozy bldr) We will be postcuring (some) in the sun under a black plastic tent in order to simulate ramp temperature ( suggestion by cozy bldr) We are planning to do the layups this weekend so any suggestions / requests will be included if not too difficult Now the disclaimer part ... Although I publish everything I learn to all of you in order to share my .02, it will allways be only my opinion only and the path I'm following does not have to be followed by any of you. All the above is to enrich each of us with the info I found, and you will use/abuse this at your own risk. Chris with Cozy #219 in chapter 8 cvh@iafrica.com Date: Tue, 29 Oct 1996 22:31:32 -0500 From: StetsonE@aol.com Subject: Re: COZY: Gougeon Bros. Pro-Set ? In a message dated 96-10-28 22:09:18 EST, Fred Mahan writes: > I looked through my back Canard pusher issues, and can't find anywhere > where Rutan/RAF/Scaled recommends Pro-Set for the homebuilder. The July > Canard Pusher refers the reader to the discussion of E-Z poxy in the > Central States Newsletter, and the April issue also discussed E-Z poxy > at length, without specifically recommending it. > I found a reference to Pro-Set in Canard Pusher Newsletter 84, page 3. Not much, just a couple of lines. Here they are: "Unfortunately alternate epoxies recommended by RAF in CP77 have since been discontinued. SCI (Scaled Composites Inc.) scrambled to find a MDA-free replacement and now uses a laminating system called Pro-Set distributed by Geougeon Brothers Inc. located in Bay City, MI." This is the only reference to Pro-Set in the CP newsletters. Stet Elliott stetsone@aol.com Perpetual Long-EZ builder Date: Wed, 30 Oct 1996 11:45:45 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: COZY: Epoxy George A. Graham Wrote: = >The biggest variable, appears to be the hardner mix chosen. The > booklet describes: >ALIPHATIC POLYAMINES- Short pot life, high exotherm, room temp > cure. > DETA,TETA,TEPA,AEP > 13% MIX,111 deg C,.09 % wt chng in jp 4. > 3.1% wt chng in 30% sulfuric acid > serious skin rash & burns even from vapors > >AROMATIC POLYAMINES - High temp cure and service (up to 300 deg > F.) > MDA,,MPDA,DDS,DADS > 17% mix, 110 deg C, .27% wt chng in jp 4 > 2.7% wt chng in 30% sulfuric acid > less rash & burn, vapors not a hazard > >ANHYDRIDES - High temp service & long cure. > NMA,HHPA,TMA,DDSA,PA,MHHPA,THPA,MTPHA > 87% mix, 156 deg C, .16% wt chng in jp 4 > .55% wt chng in 30% sulfuric acid > severe eye and skin irritation & burns > >POLYAMIDES - long pot life, room temp cure, no blushing, > outstanding = > adhesion. > dark color, poor temperature strength (< 149 deg F), wide > mixing > range. VERSAMID,EUREDUR,ANCAMIDE (trade names ?) > 43% mix, 101 deg C, .29% wt chng in jp 4 > 3.6% wt chng in 30% sulfuric acid > distinctly less hazardous than other curing agents > > >CATALYTIC AGENTS - 2 to 10 % mix used in small amounts to > accelerate other > anhydride or aromatic amines. > BDMA,BF-MEA,DICY > >Based on the above, it appears that the Safety Poxy was a mix of > polyamide >and an aromatic polyamine (MDA?). Now, if we can find out what > is in the >2427 hardner ! There is no mention of Styrene in the booklet. > >Perhaps you might have something to add ? 02/24/93 EPOLITE 2187 SLOW HARDENER SECTION 1 IDENTIFICATION = PRODUCT IDENTIF1ER.. EPOLITE 2187 SLQW HARDENER CHEMICAL FAMILY..... EPOXY HARDENER COMPANY NAME........ HEXCEL CORPORATION - RESINS GROUP 20701 Nordhoff Street, PO Box 2197 Chatsworth, Ck 91311 (818) 882-3022 (830) 433-5072 (USA-Except Ca) = (800) 343-4487 (Canada) (800) 367-7527 (California) SECTION 2 HAZARDOUS INGREDIENTS HAZARDOUS INGREDIENTS PERCENT = PPL (OSHA)/ TLV (ACGIH) CAS NUMBER 4,4=92 METHYLENE BIANILINE (MDA): 30-45% = 10 ppb (OSHA/ACGIH) 101-77-9 100 ppb STEL (OSHA) 5 pph ACTION LEVEL (OSHA) POLYMETHYLENE POLYPHENY AMINE: 15-35% = Not Established 25214-70-4 AMINE TERMINATED POLYMER: 5-15% (NM 300-400) Not Established 26376-58-9 STYRENE MONOMER 5-15% = 50 ppm TWA (OSHA/ACGIH) 100-42-5 100 ppm STEL (OSHA/ACGIH) = BENZYL ALCOHOL 10-20% = Not Established 100-51-6 EZ82, EZ83, EZ84 and EZ87 will have almost the same ingredients. Hope that helps. AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 phone/fax 910-961-2238 E-mail: JRaerocad@gnn.com NEW homepage address: http://www.binary.net/aerocad Date: Wed, 30 Oct 1996 07:51:42 -0500 (EST) From: "George A. Graham" Subject: COZY: Epoxy In an attempt to better understand the properties of epoxy resins and the curing agents, I've reread a booklet titled " DOW Liquid Epoxy Resins". If my understanding is correct, epoxy resin is bisphenol-A based organic liquid which is converted to a thermoset solid by the addition of a hardner (curing agent). The resin itself may be modified with a reactive diluent to reduce the viscosity. The biggest variable, appears to be the hardner mix chosen. The booklet describes: ALIPHATIC POLYAMINES- Short pot life, high exotherm, room temp cure. DETA,TETA,TEPA,AEP 13% MIX,111 deg C,.09 % wt chng in jp 4. 3.1% wt chng in 30% sulfuric acid serious skin rash & burns even from vapors AROMATIC POLYAMINES - High temp cure and service (up to 300 deg F.) MDA,,MPDA,DDS,DADS 17% mix, 110 deg C, .27% wt chng in jp 4 2.7% wt chng in 30% sulfuric acid less rash & burn, vapors not a hazard ANHYDRIDES - High temp service & long cure. NMA,HHPA,TMA,DDSA,PA,MHHPA,THPA,MTPHA 87% mix, 156 deg C, .16% wt chng in jp 4 .55% wt chng in 30% sulfuric acid severe eye and skin irritation & burns POLYAMIDES - long pot life, room temp cure, no blushing, outstanding adhesion. dark color, poor temperature strength (< 149 deg F), wide mixing range. VERSAMID,EUREDUR,ANCAMIDE (trade names ?) 43% mix, 101 deg C, .29% wt chng in jp 4 3.6% wt chng in 30% sulfuric acid distinctly less hazardous than other curing agents CATALYTIC AGENTS - 2 to 10 % mix used in small amounts to accelerate other anhydride or aromatic amines. BDMA,BF-MEA,DICY Based on the above, it appears that the Safety Poxy was a mix of polyamide and an aromatic polyamine (MDA?). Now, if we can find out what is in the 2427 hardner ! There is no mention of Styrene in the booklet. Perhaps you might have something to add ? George Graham Modified E-Racer # 206 Mazda Engine Installation (716) 874-3277 Date: Fri, 01 Nov 1996 22:49:07 -0500 From: Neil Clayton Subject: COZY: Conversation with Nat re 2427 Jon Lones and I called Nat re our 2427 fears; I'll try to sum-up an hours' discussion; He said he'd heard of the 'net discussion but didn't believe it was a major issue. We explained how we'd torn strips off my fuse after lifting a UNI corner with a sharp knife. He said that was typical of the material and nothing to be too concerned about. While we were on the phone he went to his shop and found an offcut from the first plane he'd ever built, and lifting a corner with a wood chisel, peeled it with the phone receiver close - we heard the same rending sound mine made! He did it again with a 2nd piece from an actual flying Cozy. He said the force he was using was "thumb & forefinger". These test pieces were both constucted using RAE SLOW epoxy; not with Hexcel/H.B. Fuller 2427 epoxy. BUT....The pieces were laid up in the arid climate of Arizona; not in the jungle climate of Central Florida. Both of Nat's test pieces were made with UNI fiberglass, not BID. Back to mine...only the UNI allows peeling. The BID is stuck fast. (Maybe this says wrap every big layup in a coat of Bid???) The "test" used by Nat and by ourselves, placed the load 90 degrees ("normal") to the surface and the design loadpath (i.e. separating a layer of glass with a sharp chisel/knife and then pulling "up" on the exposed lip created by the chisel, very similar to tearing off a piece of Scotch Tape from a roll). There are no point loads of that kind, or in that direction (ie; normal to the flying surfaces) when in flight. When we tested a scrap 22ply BID layup it showed no tendency to delaminate, but rather breaking off before tearing far. This makes a lot of sense due to the inherent cross-grain structure of having fibers weaved at 90 degress to each other in BID. Nat related the fact that Mike Melville said that these planes were designed to minimize the need for peel strength through the use of compound curves, overlaps, etc. He said the problems with 2427 epoxy seemed to start when the rights were sold from Hexcel to H.B.Fuller. However, he suggested that everyone should discontinue the use of 2427 epoxy in their projects. The next newsletter will state this, but it won't be published for another month or so. But this was due to other characteristics of 2427, not necessarily the peel characteristic. I'm sending him a small box of off-cuts. He said he'd look them over. I hope I've quoted Nat accurately here (my fault if not). I feel quite a bit better after talking to him. The idea that at least one of his flying aircraft has the same characteristic seems like it's not unique to mine, or Florida. As a Chartered Mech Eng, I like the idea that just 'cos the material (& only UNI) is poor in the peel direction, there's no reason to scrap it for tensile, torsional, shear & compressive uses (wings, etc). This is like saying concrete alone can't carry tensile loads, so I won't use it for buildings even though it will only be subjected to compressive loads. I'm not out of the woods yet...I still want to talk to Jeff R, but maybe it ain't as bleak as it seemed. More at 11... Neil Date: Mon, 04 Nov 1996 22:13:07 -0800 From: Paul Comte Subject: RE: COZY: Epoxy Choices There were 24 response to the post requesting a Aye, Nay or No Comment. 9 were in favor of the Hexcel product in question. 12 were not in favor of the Hexcel product in question. Of the remaining three, two are using that product but proposed caution while one felt since the jury was still out I may want to wait a bit before digging in. Several commented that they were surprised I was sent the full five gallons as the shelf life of this product is questionable. That is something I had given no thought to. It seems I'll have a good excuse to keep at it if I do proceed with this material. One comment that the cost difference between the systems is only a few hundred dollars, a small percent of the overall project cost. Food for thought. The award for the shortest response goes to John Williams of Heaton, ND with "NO". ! Thank you all for your comments, I've got some soul searching to do before I decide what to do. A point I would like clarified is what type of lay-ups have been parting? To find a simple point of reference I like to suggest that in general most lay-ups will fall into one of three categories. Instant application (within minutes), long lay-ups (longer than a few minutes) and layers on cured but properly prepared surfaces. I am nursing a suspicion that under some conditions the surface of lay-ups from that second category may have some nasty properties. Paul Comte Milwaukee, WI Date: Tue, 5 Nov 96 11:00:05 -0800 From: Eric_Westland@msvl.wednet.edu (Eric Westland) Organization: Marysville School Dist. Subject: Re: COZY: Epoxy test 3 cvh@iafrica.com,Internet writes: The interlaminar shear tests will only go to the lab by next wednesday, since we allow a 7 day cure period. so far the temps are 30C (85F) during the day and 24C (72F) during the nights - Relative humidity ranges between 52% to 65% - it can, however, rain while reading any %. chris #219 in chapter 8 cvh@iafrica.com ############################################### Chris, Sounds great, thanks for doing this. Since my strakes are already completed in 2427, I am particuarily interested. I still do not feel like I know what may have happened in the reported accident with the flakes appearing in the gascolator, but I have one thought that may be possible and you may want to at when you test. When you build the fuel tanks, the plans call for several additional coats of pure epoxy to help seal them. Many have reported that after the epoxy starts to "kick in" and cure, that later layers of glass don't bond well. What I am wondering is if these additional coats are not painted on in a timely matter (whatever that may be), could flexing of the skins cause these same coats to start to break down and flake off? I am doing some testing of my own at home, but I would be the first to admit that I am in over my head in this area. I am however very interested in what those of you more knowledgable than I think in the way of this "flaking" even being possible. Thanks again, Eric -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Sent via ExpressNet/SMTP(tm), Internet Gateway of the Gods! ExpressNet/SMTP (c)1994-95 Delphic Software, Inc. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Date: Tue, 05 Nov 1996 12:08:45 -0800 From: Chris van Hoof Organization: C van Hoof - Architect Subject: COZY: Epoxy test 3 Hi there again, The comparative layup tests were done last saturday and of course conditions could not be worse....temp 30C(85F) with a relative Humidity of 57%, I said you can set your watch on our rain during summer...well, we had a heatwave...? Jean (the girlfriend) and I decided that this was not a problem, since we were donated enough epoxy(ies) for another lot of test samples, we'll do the layup tests again next saturday. This time we'll use Humidifiers and a tumble drier with wet towels in the workshop (tip from cozy builder) to raise the humidity level - if we get to above 80% (large workshop) we'll attempt the test, if not it would be a waste of time and epoxy. We are currently drawing up the report regarding the test so far. The interlaminar shear tests will only go to the lab by next wednesday, since we allow a 7 day cure period. so far the temps are 30C (85F) during the day and 24C (72F) during the nights - Relative humidity ranges between 52% to 65% - it can, however, rain while reading any %. chris #219 in chapter 8 cvh@iafrica.com Date: Fri, 15 Nov 1996 09:01:26 -0800 From: Chris van Hoof Organization: C van Hoof - Architect Subject: COZY: Epoxy testing 4 Hi to all, The Epoxy test pieces have now cured for 14 days (the longest cure required on one type) and will be going to the lab early next week. The weather is playing along and we have 75% relative humidity, so it won't be too difficult to raise this to 85% with the equipment at my disposal. (Just could not raise it high enough without the help of mother nature - workshop area too well ventilated and large in volume). Will be manufacturing a test rig as described in the book COMPOSITE BASICS by Andrew C Marshall see page 10 chapter 12. Chris #219 cvh@iafrica.com Date: Fri, 15 Nov 1996 23:59:59 -0500 From: Fritzx2@aol.com Subject: Re: COZY: Epoxy testing 4 Chris van Hoof, A week ago I also made some test samples but under different atmospheric and time conditions than I think you have. You referred to a test jig in a composite book you have. I have been trying to determine how to quantify how good my test layups are but don't know how. As a minimum, I was going to try some peel testing and compare between each of the four different test samples. Could you please tell me what method(s) the book recommends using to determine adequate peel strength. Since the layups I had done on the outside of my fuse using Hexcel 2427 were done while a dehumidifier was running, I suspect that the time between the application of the three layers on the outside of fuse was a contributing factor. I did the layup alone and mixed the epoxy with a balance which takes a little more time than a pump. But, since I was not using a pump, the humidity could have not gotten to the hardener prior to the use of the epoxy at time of use aside from the little amount of air/humidtiy that was sealed inside the can. I planned on testing the samples tomorrow but now I think I'll wait to hear from you before I proceed so I can perform a more quantitative test rather than a qualitative comparison between the different samples. My way, at best, can only prove that there are or are not any differences between each test sample and between each test sample and my fuse sides. The four test samples approximately 9" x 12" were done: 1. 2427, 3 layer UND orientation like outside of fuse, done with one batch of mixed epoxy 2. Original RAE epoxy (2426 resin and slow hardener 2177), same as #1 above 3. 2427, 3 layer UND orientation like outside of fuse, 1.5 hours between plies 4. Original RAE epoxy (2426 resin and slow hardener 2177), same as # 3 above Do you think the book Composite Basics has a lot of useful info in it? I'm interested in purchasing a good composite reference text but without seeing what the contents were, I have been reluctant to mail order only to get a book without any helpful info like the jig that you referred to in your message. Thanks for your response and I look forward to hearing about your test results. John Fritz Fritzx2@aol.com Date: Sat, 16 Nov 1996 10:40:23 -0800 From: Chris van Hoof Organization: C van Hoof - Architect Subject: COZY: Epoxy test 4 Hi Jim & all cozites, Jim wrote: Thanx but what are you saying? (as it concerns me...) I'm just about to start the higher relative humididy testlayups, but don't want to waste time or epoxy. We live at +-4500 ASL, thus it would take less water to saturate a cubic whatever...Now try to bore me with the explanation you threatened with (please) but keep it simple (I'm blonde and an Architect :-)). Thanx in anticipation. chris with #219 held up in chapter 8 Date: Sat, 16 Nov 1996 10:48:58 -0800 From: Chris van Hoof Organization: C van Hoof - Architect Subject: Re: COZY: Epoxy testing 4 Hi John RE: > Do you think the book Composite Basics has a lot of useful info in it? > I'm interested in purchasing a good composite reference text > John Fritz Fritzx2@aol.com Have not read the complete book...a Cozy builder referred to it in one of the letters....A/C Spruce (RSA) informed me who was the latest buyer, I contacted him and allowed me to use the book in order to do the test described...so that others may copy same at their homes....I will describe the rig later and the formula that goes with it. Chris with #219 in chapter 8 Date: Mon, 18 Nov 1996 00:00:59 -0500 From: Jim Hocut Subject: Re: COZY: Epoxy test 4 Chris van Hoof wrote: Now try to bore me with the explanation you >threatened with (please) but keep it simple (I'm blonde and an Architect > OK, I opened my mouth, so I guess now I've got to back it up. What I'm getting at is that the rate that we're going to see epoxy react with water vapor in the air depends on how many molecules of water there are in a given volume of air (moles per liter). This is absolute humidity, or just plain humidity for short. This is also directly proportional to the dew point (i.e. air with a dew point of 15 deg C ALWAYS has fewer molecules of water per liter than air with a dew point of 20 deg C) Relative humidity, on the other hand, only refers to how saturated the air is (i.e. at a relative humidity of 80% the air is holding 80% of the water molecules that it possibly can at the current temperature). This isn't really telling us anything about how many molecules of water that are present to do bad things to our epoxy. At a relative humidity of 60% on a hot day there may actually be more water molecules present to ruin epoxy than at a relative humidity of 70% on a cool day. So, the only proper way to use Relative Humidity in this context would be to hold the temperature constant, that way we'd be comparing apples to apples. I hope this kind of sort of explains things. I'm rather tired right now and not real with it, so if I need to do better a better job of backing myself up let me know and I'll give it another shot when I'm more coherent. Jim Hocut jhocut@mindspring.com Date: Mon, 18 Nov 1996 08:42:29 -0800 From: Chris van Hoof Organization: C van Hoof - Architect Subject: COZY: Epoxy test 5 Hi to all interested in the Epoxy comparative testing 2427 Epolite The 2nd lot were done on Saturday with the Temp a 20C (65F) and the relative humidity at 80%. I'll go into more detail later but there was a noticable difference in the feel of some of the Systems....worst case was the 2427 Epolite....It felt thicker than during the higher temp (expected) but during the 2 minute stir & scrape session (normal not vigorous), it got very airated and was _very_ slow in releasing these bubbles, this repeated itself during the wetout but to the extent that it trapped the bubbles (miniscule in size) and it tainted the layup whiteish - this discolouring did not settle and is still there on Monday morning. The curing went sort of normal but somewhat slower (due to the lower temp) Jefco/Proset The Proset still had a revolting strong smell and I surely would not build an aircraft (or anything else) with that stuff. The last two layups done were proset and then Jefco (this had a faster hardener with it and may not give a good comparison) - at this stage my eyes started itching something terrible - this kept on during the whole of Sunday and seems to have cleared now (Monday) I would put money on it being the hardner supplied with the Jefco (the faster - the more agressive?) - but because of the stink Proset is not ruled out - of course all hardners are aggressors in this enviroment - and the workshop was not as well ventilated as normal (for me). My opinion only. chris with #219 soon to progress. Date: Tue, 19 Nov 1996 11:14:21 +0200 From: Rego Burger Subject: COZY: Epoxy test 6 -Reply Thanks Chris van Hoof, For epoxy test 6......... I pulled my peelply off the leading edges last night off the strakes. In about five spots about 1/2" patches of pure resin turned into white flakes. If I blew hard enough they came off like dandruff. I attacked the surface with a knife, I could NOT lift the laminate without cutting into it! Once cut I tried to "peel" the skin back, the glass broke about 1/4" back. On closer examination the areas that "flaked" had not been sanded well and I now remember I FORGOT to clean off that area with acetone or thinners. The waxy surface "blush" caught me napping on this one! If I had to give a subjective rating of 2427's adhesive qualities I would only give it an 8 out of 10! It needs a 20% better surface prep than 2022 for mechanical bonding according to my findings. I also fear guys who try to pour in a slosh compound will have added problems on a resin rich interior ( even less grip ) besides that they will be faced with the hassle of not getting the slosh on the strainer inside. Just remember NEVER even think of pouring fuel in the tank within a 14 day period, 2427 is an extremely slow curer without elevated heat! After 4 days one can still feel a mild tackiness on the surface, this is that waxy stuff. A mild acetone (clean) rag helps to get rid of this, it's extra work, but important. Can you imagine what your final finishing micro has to grip onto? The only benefit 2427 has been for me is to sharpen my preparation skills, the 2022 resin has been more forgiving in this regard. Aircraft Spruces advert says: "2427 contains no MDA...provides an increase in impact resistance,flexural strength and tensile strength.........is excellent for all homebuilt aircraft applications formerly using Safety-Poxy." Rego Burger Port Elizabeth RSA Cozy Mk 4 #139 ( strakes skinned and lined with 2427, outboard wings skinned ready for winglets and aileron cutout, turtledeck and canopy to go on soon.) Date: Tue, 19 Nov 1996 09:27:56 -0800 From: Chris van Hoof Organization: C van Hoof - Architect Subject: COZY: Epoxy test 6 Hello there again, Still on the subject of comparative testing. Last night I started trimming the pieces that were laid out with the 80% Relative Humidity and the 20C (65F). At the end of trimming the 16 layer strips, the work was done and iidle hands picked up the waste of the 2427 Epolite (3/4" wide/7"+long/16layers), I bent it to see how it flexes (you know, with the thumbs in the middle facing each other and the index fingers forming the outside hooks) and it snapped like a cheap pencil, surprised I tested the 2410 (this was only 1/4"w/7"L/16Layers) and there was No Way that this wanted to break using my hands only. The 2427 wastes from the 30C (85F) 57% Rel Hum layup could also not be broken (also only 1/4"w/7"L/16Layers) This is only an early observation, but worrying enough to issue to all. My opinion only Chris #219 Date: Tue, 19 Nov 1996 15:43:06 -0700 (MST) From: Roy Grossinger Subject: Re: COZY: Canard Dihedral > Another idea I have been toying with is to use this canard as a test sample > for an ultimate load test, test it to failure. (sometimes it can be a lot of > fun to break things!). What would a test like that prove? Maybe not much. > But if it did actually hold up through the design load limits, then we would > know that it is at least possible to build a safe airplane out of the 2427 > epoxy. This would prove A LOT! Nothing better then to test an actual part, not to mention you didn't use extra precautions now that we believe 2427 is a problem. Boeing actually has to build and break, yes break any new wing design. If you decide to build a new canard, take the old one to your local University, the Engineering department would love you for it. Their students could test the canard for you and it would be a win-win situation. We did a similar experiment at the University of Colorado concerning a stabilizer spar. Three were built, the first was a vacuumed abortion, the second was perfect and was also vacuum bagged, and the third was not vacuumed bagged. The non-vacuum bagged spar broke first, the second was the thing that looked like it wasn't strong at all the vacuum bagged abortion, and the best on was the nice looking vacuum bagged one. Measuring strength/weight ratio from the highest as 100%, the second failed at 95% and the third at about 82%. remember that the third looked as good as the first. When you took into consideration the extra weight, its strength/weight was rather low. All of these were done using 2427. The end result was we used some carbon fibers to beef up the spar, and vacuum bagged the piece. Since I've climbed onto the soap box, I also have a bone to pick with Chris van Hoof. When you start an experiment you should not try to form an opinion about the result before you actually do the experiment, analyze the data, present the data and have peer review! Also the tid bit about breaking the 2427 piece between your fingers is the best test I've ever heard of. Causing a sharp break in and fiberglass layup will cause the epoxy to crack locally, breaking the glass fibers. Cure times are different for many epoxies and who knows if the one that did bend just wasn't cured yet. This finger test is worthless in my opinion since the fiberglass, we all hope, isn't subjected to this type of stress in our aircraft, and isn't designed for this kind of stress. What in your mind was proven by this test? ============================================================================= Roy H. Grossinger- ME grossinr@rastro.colorado.edu Cozy Mk IV #503; Chapter 7 ROY_GROSSINGER@Radon-hq.ccmail.compuserve.com | ___ | http://www.abwam.com/grossing |---------(>-<)---------| o/ ~~~ \o "A man's destiny is his character" Date: Wed, 20 Nov 1996 09:37:36 +0200 From: Rego Burger Subject: Re: COZY: Canard Dihedral -Reply Roy Grossinger picked a bone with Chris van Hoof regarding his opions of 2427. >Since I've climbed onto the soap box, I also have a bone to pick with Chris van Hoof. When you start an experiment you should not try to form an opinion about the result before you actually do the experiment, analyze the data, present the data and have peer review! Also the tid bit about breaking the 2427 piece between your fingers is the best test I've ever heard of." Chris wrote... >"This is only an early observation, but worrying enough to issue to all. >My opinion only" Lovely thing this cut and paste...:-) This is how Chris van Hoof ended his letter on the report he made about a finger test of workshop samples. All the layup samples have been sent to a University type lab, these results will be made soon as done. From a journalistic point of view his enlgish is correct --"My opinion only" He did not say Proof of anything. Chris did not vene say what the fibre orientation was, if the sample was made with UND it would be only 10% strong in one plane, so BOO! A finger pressure would snap it like a tooth-pick. All the samples sent to the CSIR are 3.5mm thick made with the same cloth in the same orientation and ONLY using different resins, to try and compare their influence in the structure. 3 sample of each are sent and labled numerically not to influence the Lab. Technician. He will print the results accordingly, Chris will then publish the LABS findings, he may pass is opinion so labled, you choose for yourself ! My independant tests and practises have found only one labour intensive problem, to get good mechanical bonding with 2427 it MUST be cleaned with acetone to remove it's waxy amine blush even if sanded and peel plyed. It formed white flakes in some spots when pulling peel ply off tapes that were not well cleaned this way! Rego Burger Port Elizabeth RSA Cozy Mk 4 #139 Date: Wed, 20 Nov 1996 06:50:02 -0500 (EST) From: "George A. Graham" Subject: COZY: Re: 2427 Epoxy On Wed, 20 Nov 1996, Rego Burger wrote: > My independant tests and practises have found only one labour intensive > problem, to get good mechanical bonding with 2427 it MUST be cleaned > with acetone to remove it's waxy amine blush even if sanded and peel > plyed. It formed white flakes in some spots when pulling peel ply off > tapes that were not well cleaned this way! Rego, The West Systems epoxy manual says that the amine blush can be removed with water and an abrasive pad (3M - like Scotch Brite/ pots and pans scrubber). That is what I've used instead of acetone. I think it works OK. George Graham Eracer #206 Mazda Rotary Engine (716) 874-3277 Date: Wed, 20 Nov 96 10:59:39 est From: "Larry Schuler" Subject: COZY: Re: 2427 Epoxy George Grahm wrote: >Rego Burger wrote: >> My independant tests and practises have found only one labour intensive >> problem, to get good mechanical bonding with 2427 it MUST be cleaned >> with acetone to remove it's waxy amine blush even if sanded and peel >> plyed. It formed white flakes in some spots when pulling peel ply off >> tapes that were not well cleaned this way! >Rego, The West Systems epoxy manual says that the amine blush can be >removed with water and an abrasive pad (3M - like Scotch Brite/ >pots and pans scrubber). That is what I've used instead of >acetone. I think it works OK. FWW: I was looking at the ProSet literature this last weekend and read the same thing about removing the blush with plain warm water and a Scotch Brite pad. I get nervous thinking that solvent residue might be left behind in the pin holes and foam edges.... Water seems a bunch safer (coure ya never know what might be in the stuff we drink). They also mentioned that peel ply will always remove the blush and therefore not require scrubbing. BTW: The info they provide on the ProSet performance is infinately better than that provided on 2427. Personal opinion: I think they have some great stuff; at least very helpefull folks and very free with info and assistance; price "might" be equivalent to the quality perhaps (get what ya pay for). They have a number of hardners and epoxys; some "REQUIRE" post cure. They also highly recommend both vacc bagging and post cure; but state that room temp cure and no bag is ok, but performance is less. An interesting part of the literature speaks about how the glass to resin ratio can be controlled with the amount of vacuume pulled. Makes me wonder if my max goal of 12 to 12.5 lb/sqin has been too much????? Anyone have any additional info on this? I know it's 12 to 12.5 lb because I'm using a 0 - 15 lb pressure guage with the gears changed so it reads a vacc on same scale (may not be lab quality but the guage was free). They say pin holes are normal with vacc bagging as the vacc pulls air/gases out of the core material during cure (especially at higher vacuumes). Answers my questions about the pin holes I have in vacc bagged parts and not in others. I'm not affraid of 2427 (long as I pay attention); just looking at alternatives for when I run out. Found the above, and thought it might be usefull. Larry Schuler MKIV-#500 Ch-6 Building forms for bottom, prep for vacc bag. Date: Wed, 20 Nov 1996 13:33:35 -0800 From: Chris van Hoof Organization: C van Hoof - Architect Subject: Re: COZY: Epoxy TESTS Roy Grossinger wrote: Since I've climbed onto the soap box, I also have a bone to pick with The fact that you do anything in life makes you open to all sorts of criticism, thanx for the reaction anyway. > When you start an experiment you should not try to form > an opinion I had an opinion before I started. Man, you give me the subject and i'll have an opinion :-) show me a person without an opinion and I'll show you a person who is not thinking :-) > present the data and have peer review! You can review all you want, when its finished, but without me :-) I'll only react when something needs clarification regarding the test. > Also the tid bit about > breaking the 2427 piece between your fingers is the best test I've ever > heard of. Causing a sharp break in and fiberglass layup will cause the > epoxy to crack locally, breaking the glass fibers. Cure times are > different for many epoxies and who knows if the one that did bend just > wasn't cured yet. This finger test is worthless in my opinion since the > fiberglass, we all hope, isn't subjected to this type of stress in our > aircraft, and isn't designed for this kind of stress. What in your mind > was proven by this test? The only thing this showed was that there was a difference in the properties of the two separate 2427 Epolite layups. One of the reasons for doing this test is to put something back into the forum, you Cozy builders have helped me so much with your discussions. To us in far away Africa, this forum is like being able to attend Oshkosh on Cozy day. The sporadic issue of observations/opinions is to show that some progress is made / the tests have not been abandoned / and something is being done. Probably, each issue of eMail regarding this lot is to motivate myself, I promise you I'd rather be building on my Cozy and the testlayups are REAL boring - 16 layers UNI X 9 Epoxy systems + 3Layups X 9 systems and all this twice - once with low humidity / high temp and once with low temp / high Hum, then trim each to prepare for the lab, cut each into 10 pieces of 1/2" X 1" - label, seal & soon to go to the lab. All for NO personal gain whatsoever (My System - Epolam 2022 - is approved for use in aircraft):-) of course you can't take away the experience of working /feeling all the systems and all the interesting applications I've seen /heard about. And while I'm on a roll, THANKS to MARC ZEITLING for giving us this opportunity to communicate. No offence meant to anyone, none taken either, having fun in my little corner thanx. Chris with #219 tugging on my trouser to get moving. Date: Thu, 21 Nov 1996 15:30:46 -0700 (MST) From: Roy Grossinger Subject: Re: COZY: Epoxy TESTS My sincere apologies to Chris if my tone was too harsh, I have nothing but admiration for someone to invest his time into this test. I've also been told by others I can be a little blunt and I try to harness that. My sincere thanks to Chris for all of his efforts to the idea, time, effort, and testing of the epoxy layups. We all know how boring making a part is if it isn't going into your airplane. I really am looking forward to the results of a standardize (as much as possible), quantitative, reproducible test. From what I have heard Chris is doing all that with the layups and I can't wait to look over the data myself, and if possible would love to try to reproduce the data. However my first impression of the finger test sent me asking questions about it. The line (my opinion) was right, I just didn't read that. I had felt Chris was trying to prove something with a test that didn't have any of the above, forementioned attributes and I wanted to point this out to the material testing laymans in this group. In any case I hope I have not underminded Chris' determination and resolve to complete the test. I don't want to hinder but help if possible. ROY > The sporadic issue of observations/opinions is to show that some progress > is made / the tests have not been abandoned / and something is being > done. Probably, each issue of eMail regarding this lot is to motivate > myself, I promise you I'd rather be building on my Cozy and the > testlayups are REAL boring - 16 layers UNI X 9 Epoxy systems + 3Layups X > 9 systems and all this twice - once with low humidity / high temp and > once with low temp / high Hum, then trim each to prepare for the lab, cut > each into 10 pieces of 1/2" X 1" - label, seal & soon to go to the lab. > All for NO personal gain whatsoever (My System - Epolam 2022 - is > approved for use in aircraft):-) of course you can't take away the > experience of working /feeling all the systems and all the interesting > applications I've seen /heard about. Ditto........ > And while I'm on a roll, THANKS to MARC ZEITLING for giving us this > opportunity to communicate. Date: Fri, 22 Nov 1996 09:46:15 -0800 From: Chris van Hoof Organization: C van Hoof - Architect Subject: COZY: Epoxy tests General Hi all, Thanx to all your votes of support (This can't be proper English :-)) No offence was taken and none meant at all! The limitations of the eMail system come to the fore in a forum like this one - after all we are all pushing the same wheel. - probably won't be long before we all have a video camera on top of our screens - suppose then we won't like the other guys'face? :-) Just to show that I'm the first one to jump to conclusions and opinions, here goes. The other waste piece on the 2427 Epolite tested last night was as hard as nails, no fingertype stress test was going to break this little strip (1/2"w/7"L/1/8"thick Uni) maybe just takes longer to cure to same hardness after being laid up in low temp/high hum. Now the sad news: The lab returned my samples as they were not thick enough. They were supposed to be 3.5mm to 4mm Max and my samples were 3.45 to 3.1mm . So tonight or this weekend (conditions being the same as during the original layups) We will add 3 layers of UNI to each, the samples have allready been roughed with 40 grit sandpaper. - Also if enough Epoxy is still in hand we'll do the whole layup again to see if there is any difference in the qualities.( a whole layup vs a joined layup). The programme is as follows: Layups this weekend Cure of high hum/low temp (14D)ends next weekend. Cure of Low hum/high temp ends weekend after Do tests as per Composite Basics book weekend of 6 Dec (latest) All parts to lab by 6 or 9 December (depending on my workload) Publish results of the Composite Book Test* Publish results of the CSIR tests as soon as available Then it should be done. Now I need some advice regarding copyrights, In South Africa were not supposed to copy anything for whatever reason without prior permission. What would be the case in the USA if I scanned the 2 pages of the Composite Basics regarding the test subject. That would make it available to everyone...anybody know? * these tests may be done sooner, since the last parts will be final cured by next weekend, & the first layups are cured allready - let you know as they are done. Chris #219 Date: Sat, 23 Nov 96 06:38:06 +0000 From: cac%exo.com@exo.com Subject: Re: COZY: Gougeon Bros. Pro-Set ? > >I've been hearing about Gougeon Bros. Pro-Set for a little while now. > >Anyone know where it's available? Anyone have experience with it? > > You can get it from Svendson Marine in Alameda, CA (510) 522-7860. We use > the 125 resin and the 229 hardiner - it's tough, wets out terrifically, VERY > strong. Scaled uses it for almost everything now. > Anyone know what Nat thinks about this stuff? After 2427 I am a little nervous about anything other than RAE Or Safe-T-Poxy. Date: Sun, 24 Nov 1996 12:37:33 -0800 From: Chris van Hoof Organization: C van Hoof - Architect Subject: COZY: 2427 Hi all, I was told that 2427 Epolite needs 14 days cure at 75F to get up to strenght, can anyone confirm this - have no access to literature on this. Thanx in anticipation. chris #219 Date: Sun, 24 Nov 1996 18:03:45 -0500 From: Fritzx2@aol.com Subject: Re: COZY: 2427 Cure time Chris van Hoof wrote: >I was told that 2427 Epolite needs 14 days cure at 75F to get up to >strength, can anyone confirm this - have no access to literature on this. The January 1994 Technical Data Bulletin (I requested this bulletin from Hexcel in September of 1994 and it was still the most current one then) from Hexcel states for 2427, "Curing: Near ultimate physical properties are normally attained after sixteen (16) hours or room temperature set plus eight (8) hours at 150 degrees F". As you can see, the bulletin does not specifically state that the 16 hours is at room temperature since it says "...after sixteen (16) hours _or_ room temperature set plus eight...". You could assume, I guess, that the 16 hours is at room temperature also. All the other properties in the bulletin such as viscosity, density, and pot life are given at 25 degrees C. They do not specifically state that room temperature is 25 degrees C but I think you could also make that assumption. In addition to the curing time, the bulletin also states: Pot Life for 100 grams at 25 deg. C: 125 minutes Pot Life for thin film at 25 deg. C: 3-4 hours Tack-free time for thin film at 25 deg. C: 5-6 hours If you need any other information, let me know. John Fritz Date: Mon, 02 Dec 1996 11:53:28 -0800 From: Chris van Hoof Organization: C van Hoof - Architect Subject: COZY: Epoxy Tests penultimate 9 Hi to all Cozy Builders, Lets start with the disclaimer part ... Although I publish everything I learn to all of you in order to share my .02, it will allways be only my opinion only and the path I'm following does not have to be followed by any of you. All the above is to enrich each of us with the info I found, and you will use/abuse this at your own risk. Over and above the foregoing, my machine does not have a spellchecker, so anything unclear will be explained on request. This is written in the "WE" form because of all the help received from various sources, so where a slip occurs and you read "I" kindly substitute with "WE". When mistakes were made read "I", since I know what I want, even if it is being wrong at the top of my voice. Now I must take the opportunity to acknowledge the help received from my girlfriend, Jean Bowden for all the support and layups done (see j in layups), also thanx to Rego Burger for enduring and doing the seemingly endless measuring during the flextests, also ALL Cozy Forum participants for your advice, critisicm (many times quite valid) and letters of support. So then, here goes with more than you probably asked for. All tests (Etc) were measured in METRIC and Temperatures in CELCIUS - all conversions mentioned in this writing are APPROXIMATE - for accurate results - use the correct conversion yourself. A1 - ORIGINAL PURPOSE OF THE TESTS Just to reiterate: that is to refresh the memory without having to read all the previous eMail. These tests were started due to some Cozy Builders experiencing problems with 2427 Epolite, as well as my curiousity regarding all sorts of Epoxy Systems. Personally, due to my remote location in the world (South Africa), I substitute materials, and all the following is interesting to me as well. The idea is to do some type of home-test system on all types at the same time, same day and therefore the same conditions, in order to obtain some sort of comparative data of use to all of us. Then came the Humidity issue and since there was enough Epoxy left we thought it would be fun & interesting to see if there really is/was a difference in the workability and/or properties of the Epoxy Systems ( more later). A lot of suggestions were made to assist in the manner of tests and thanx to all who contributed (ALL!:-)) A few eMails went out of this machine, many with the intentions, others with info regarding our deeds done, (these were not necessarily the same as the intentions.) There are basically two definite tests being done : B1 - INTERLAMINAR SHEAR TEST This consists of 10 pieces of +- 1/8" x 1" x 1/2".( I say +- because its converted from metric) these will be taken to the Lab. where they will execute the test. The idea (I understand) is to exert a horizontal force over the pieces and see (measure) at which point they stop holding together. They wanted 10 testsamples in order to get some average. Each piece is made out of 16 layers of UNI with the fibre orientation parallell to the 1/2" side (why ? just because). the reason we went for the UNI is that I got to be under the impression that most problems were expierenced using UNI, and the Lab said it did not matter much which fibres are used because the test homes in on the Epoxy. This is not done yet but samples go to the lab by 6 December 1996 The Lab asked for samples between 3.5mm and 4mm thick x 12mm x 25mm B2 - FLEX TEST This consists of flexing one test sample, supported over a known distance, by pressing a measured force, up to the point where it collapses. This is the test referred to in Andrew C Marshall's book COMPOSITE BASICS (ex A/C Spruce & surely others?). Our test may not be the most accurate, but we're doing our best here. ( there are a tremendous amount of variables that could influence this) Also our reasoning is : if we are accurate in repeating each test/ test sample size / thickness, then surely this will produce a comparable figure?. The samples on each Epoxy consist of 2 pieces +- 1/16" x 6" x 1" made of 3 layers UNI direction parallel to the 6" side. These samples were finished with peel ply which was removed 24 hrs after the layup ( because I could not keep my fingers off it, see) This test will only be able to determine if certain Epoxies have a higher or lower strenght than another, because the Uni is the same (from the same roll), the sample sizes are the same, the test rig is the same? This rig will be built this weekend (plan) The samples made were ranging from 0.9mm to 1.1mm thick depending on system and 25mm wide x no less than 150mm long B3 - THEN THERE IS ANOTHER This is where we start wallowing. One of the local chaps figured that we should attach one testpiece to a given sample with its original Epoxy as the adhesive. So the local KISS agent supplied us with a strip of the honeycomb type material, which was roughed with 40 grit along 1" and we will now attach a 1" strip (as in 2 above). The adhesion area will be 1"x 1" - the whole little affair looks somewhat like the cardboard fan on stirring stick they give out at Oshkosh. We still have to devise a manner to test this. The reason : there are many people changing Epoxy midstream on the construction ( allergies/availability/kits/etc) & the use is many times just to adhere on part to another, frankly I don't really know what were testing, but bet my bottom dollar, we'll devise some sort of answer from this, ANY IDEAS ? (all welcome - including critiscm!) C1 - SYSTEMS TESTED Previous eMails described materials that were to be obtained, when they arrived some were not as expected (Some builders have NO idea _what_ they are using - in these cases we (EAA 322) sent spies out to check that they were using their product correctly - fact: some people don't have a memory but rather a forgettery). The systems tested may not be truly comparable on a 1 on 1 basis, but where possible they were included anyway (for fun?). Here we refer to JEFCO - this arrived here with a "fast" hardner, this is used in the Lancair construction and is not really used for layup but more for assembly (?) and speed of work - have a look in the descriptions. Each one numbered 1 to 9 in order of mix ratio, why, because thats the way I did it - notice #9 came late and was not available for the first layups, this is also the markings on the envelopes as they went to the lab. 1 JEFCO Resin 1307 Hardner 3102 Mix 100:25 2 PROSET Resin 125 Hardner 226 Mix 100:30 3 EPOLAM 2020 system Mix 100:34 4 EPO 685 system Mix 100:38 5 REA HP system Mix 100:38 6 EPOLAM 2022 system Mix 100:40 7 EPOLITE 2427 system Mix 100:44 8 EPOLITE 2410 Resin 2410 Hardner 2184 Mix 100:44 9 SP Epoxy system Mix 100:25 All mixing done on the Rutan type balance scale, this was set using nails to get the quantity, then mark off on scale, scramble nails, & reset again. All cures allowed 14 days, at the prevailing temps. One more opportunity for recognognition and saying thanx: JEFCO was donated by professional builder Peer van der Walt, and came without literature or other data, other than the mixing instructions. PROSET 125/226 was donated by Peter How from Composite Technologies, who is also the local KISS agent, it came in its original box, with literature, and it is the Gougeon Bros.Trademark. EPOLAM 2020, EPO 685, EPOLAM 2022 were donated by AMT (ADVANCED MATERIALS TECHNOLOGIES) a local importer/exported of these type products, each came with a full specification sheet. REA HP was donated by Peter How (He is also a local "Approved Person" - delegated inspection/approval system for homebuilders from our DCA (local FAA)) and this is manufactured by REA INDUSTRIES (somewhere in France) this came without literature, other than the mixing instructions, the amount supplied is just short to complete the thickening layup (see other eMail),but they promised a little extra is on its merry way. EPOLITE 2427 was donated by Rego Burger Cozy builder leading the field here in South Africa, and is the same as is used in some parts for his Cozy. He had a hand in the test process. As with any product from USA, no literature or specification. EPOLITE 2410 was donated by Alphonse Gessler, a Velocity builder near here. No literature available except whatever on the box and all arrived here with mixing instructions only. S P EPOXY was donated by Ron van Lear, a Europa builder near here, no literature available except mixing instructions. D1 - SO THIS BRINGS US TO THE TEST LAYUP #1 The first layups were done on the 2nd November 1996 Relative Humidity @ start = 59% at completion = 57% Temperature = 30C Thru'out (85F) Of course due to an error on my part (real DUMB kid -me- sometimes) only 13 layers of UNI were done each for the interlaminar shear tests so +- 3 weeks later when Climatic conditions were similar the 2 or 3 layers were added to each system (this was done as required 2 or 3) after being sanded with a belt sander (80 grit). Someone came up with the idea of grading the "pleasure" or "workability" of each system, so where applicable 1/10 = bad - 10/10 = good. Smells were also graded, since some wannabees need to convince their spouses. All you hardcore builders disregard this one. :-) Smells are very personal - ie - I just love 2410 Epolite, in fact when they bring out the aftershave version, I'll use it - however - another Cozy Builder on the forum says it makes him sick... so go sniff for yourself. :-) 1996/11/02 System/who Time Wet Out Smell Notes 1 JEFCO c 4:05-4:15 Exotherm STINK dry @ 5:05 2 PROSET c 4:26-4:37 OK 9/10 STINK 3 EPOLAM 2020 j 4:46-5:04 Nice 8/10 OK/None 4 EPO 685 j 5:20-5:32 7/10 V Slight stink 5 REA HP c 5:29-5:35 6/10 Slight Aromatic 6 EPOLAM 2022 j 4:24-4:40 Battled 6/10 V Slight smell OK 7 EPOLITE 2427j 5:10-5:25 9/10 V Slight stink 8 EPOLITE 2410c 4:52-5:06 5/10 Smells OK SP EPOXY tested during the thickening layups on 1996/11/24 9 SP Epoxy 2:33-2:47 OK VV Sl Stink like proset And thats this one. D2 - THEN THERE WAS THE SECOND LAYUP The second layup was done without error (we do learn). Relative Humidity 80% Thru'out Temperature 20C Thru'out (68F) System/who Time Wet Out Smell Notes 1 JEFCO c 3:05-3:12 3:13-3:20 Difficult V Sl STink 2 PROSET j 2:14-2:38 OK Strong 3 EPOLAM 2020 j 2:44-2:58 OK NIL Sl foamy 4 EPO 685 c 3:01-3:22 V nice NIL 5 REA HP j 2:39-3:00 Fantastic OK Easy/light 6 EPOLAM 2022 c 1:55-2:09 OK OK 7 EPOLITE 2427j 2:19-2:33 OK/foamy NIL see later 8 EPOLITE 2410c 1:52-2:09 OK NIL SP EPOXY tested during the thickening layups on 1996/11/24 Notes - 2427 Epolite foamed terribly during mixing, maybe foamed is incorrect, rather aerated, got itself full of bubbles which did come to the surface after a _long_ time, and showed themselves fast again when stippling - they appeared to stay there - but there was no sign of excessive whiteout after cure. - EPO 685 showed the same tendency but released its bubbles much quicker and did not seem to want to retain them. - Jefco hardner was as thick as molasses - strange since the story that went with it said it was suitable down to 6C (38F). Thus went the second layup. THE SAMPLES WENT TO THE TEST LABORATORY. where the instruction on the last layups reads "test after 1996/12/06" the second layups are ready for testing, but maybe they want to do all at the same time? left it to their discretion to decide (they are not charging, thanx). The samples get there by 1996/12/02. FLEX TEST The flex tests were done on a machine as decribed in the COMPOSITES BASICS Book 4th Ed by Andrew C. Marshall see p 12-10. Since we had 2 strips each to test. We made full use of this by testing each end, this gave us 4 readings on each Epoxy System and should give a fair indication of the flex. Remember this is a HOMETEST, we did our level best to obtain a fair result, and since I was the only one that knew the Number/System relation, it was interesting to hear Rego Burgers comments as we progressed with the flextest.(he did not know). Readings were taken with a slide vernier at the same point, all by Rego Burger (Cozy #139) at extreme patience, and enduring my checking. Loading was carried out with a scissor jack (auto variety), hand twisted by yours truly, checked by Rego. Measurement was taken on the internal disk of an ordinary bathroom scale on the shadowline created by the overhead lights. The startup level was established as a constant at 87.4mm. The breakpoint was determined by Rego listening & watching the scale, and the moment that the sample (a)broke, (b) slid into the channel. The Second reading is the opposite side of the sample. 1996/11/30 10:30am TEST 23C (71F) ROUND 1 Testing Low Hum / High Temp samples (see decription earlier) Temp 23C #/TYPE 0Kg 5Kg 7.5Kg 10Kg Breakpoint Kg 1 JEFCo 87.4 83.0 80.0 77.5 10.5 81.5 78.5 --.- 8.0 2 PROSET 87.4 83.5 82.0 79.0 11.5 83.5 81.9 79.5 13.0 3 EPOLAM 2020 87.4 83.3 81.0 78.5 11.0 83.3 81.0 78.6 11.0 4 EPO 685 87.4 81.4 78.7 --.- 8.5 81.7 79.2 --.- 9.0 5 REA HP 87.4 82.9 80,2 77.5 10.5 84.1 82.7 81.0 16.0 (15Kg=76.3) 6 EPOLAM 2022 87.4 83.4 81.1 78.7 12.0 83.9 81.9 79.0 12.5 7 EPOLITE 2427 87.4 82.6 80.4 77.0 10.5 83.4 81.4 78.4 11.5 8 EPOLITE 2410 87.4 82.8 81.6 77.2 10.5 82.1 79.1 --.- 9.5 Then came the High Hum / Low Temp samples - TEST Temp 24C #/TYPE 0Kg 5Kg 7.5Kg 10Kg Breakpoint Kg 1 JEFCo 87.4 81.8 78.8 --.- 8.0 clean break 83.1 80.7 --.- 9.5 clean break 2 PROSET 87.4 83.3 81.6 77.9 12.5 83.5 81.5 79.2 13.0 3 EPOLAM 2020 87.4 83.6 81.6 79.6 13.0 83.2 80.9 77.5 11.0 4 EPO 685 87.4 82.6 80.5 --.- 9.5 83.4 81.5 79.0 12.5 5 REA HP 87.4 82.7 80.4 77.5 11.0 82.9 80.2 77.0 10.5 6 EPOLAM 2022 87.4 83.4 81.7 79.0 12.0 83.0 80.7 77.7 11.0 7 EPOLITE 2427 87.4 83.8 81.2 78.5 12.0 (1.0mm) 84.0 82.5 80.0 14.0 Break (1.2mm) 8 EPOLITE 2410 87.4 83.8 81.8 79.7 12.0 84.0 81.1 78.3 12.0 9 S P Epoxy This was not tested - cure not complete. SAME DAY - ROUND 2 Now we test the second set of strips but in a different sequence. High Hum / Low Temp samples - TEST Temp 25C #/TYPE 0Kg 5Kg 7.5Kg 10Kg Breakpoint Kg 1 JEFCo 87.4 82.0 78.2 --.- 7.5 84.2 82.2 79.9 10.0 2 PROSET 87.4 83.8 81.6 79.0 12.0 84.0 82.0 79.5 12.0 3 EPOLAM 2020 87.4 84.0 82.4 80.0 13.0 83.6 81.4 79.0 11.5 4 EPO 685 87.4 84.0 82.2 80.0 12.5 83.5 82.0 79.8 12.0 5 REA HP 87.4 83.4 81.0 77.4 10.5 83.3 80.5 --.- 9.0 6 EPOLAM 2022 87.4 83.7 82.0 80.0 12.0 84.0 82.1 79.6 11.5 7 EPOLITE 2427 87.4 84.4 81.9 81.0 13.5 85.3 83.7 82.0 15.5 8 EPOLITE 2410 87.4 84.0 81.6 78.3 12.0 83.8 82.0 79.6 12.0 and then Low Hum / High Temp samples - TEST Temp 25C #/TYPE 0Kg 5Kg 7.5Kg 10Kg Breakpoint Kg 1 JEFCo 87.4 83.2 80.9 77.7 10.5 83.4 80.7 --.- 9.5 2 PROSET 87.4 82.5 80.0 --.- 9.5 83.0 80.6 --.- 9.5 3 EPOLAM 2020 87.4 82.4 78.4 --.- 9.0 82.3 79.8 --.- 9.5 4 EPO 685 87.4 83.5 81.5 78.8 11.5 83.5 81.5 79.0 12.5 5 REA HP 87.4 83.6 81.6 78.8 11.5 83.5 81.4 78.8 11.5 6 EPOLAM 2022 87.4 82.6 80.0 --.- 9.0 83.0 80.2 --.- 9.0 7 EPOLITE 2427 87.4 84.0 82.0 79.8 12.0 83.2 81.2 77.3 10.5 8 EPOLITE 2410 87.4 83.4 81.2 75.4 10.0 Fail 82.3 79.2 --.- 8.5 9 SP Epoxy - not tested - still curing Thats that - don't tell me - I'm now more confused than before! Regarding the test described in the COMPOSITE BASICS Book. (You must convert from Metric!) The above test can be used to calculate the load on the surface fibers of the test specimen - use F = 3PS/2W x t x t where: F = the fiber stress in bending at the surface at failure (ultimate stress), in pounds per square inch, or psi. P = the load, in pounds, that was read on the scale. S = span, in inches, that the specimen is bridging. (50.3mm in this case) W = width of the specimen (25.2mm in this case) t = the specimen thickness (1.0mm in this case - if not then noted at reading) NOTE: If required the test can be repeated on the centre portion of each strip, but will only give one reading each. There is one extra strip of each layup High Hum / Low Temp left if this needs checking. The machine (test rig) is still intact and will remain so till the end of the year, just incase. Rego Burger brought a piece of the fuse cutout. this was tested on the same rig and yielded at about 18 Kg, but more about that later. HOPE THIS HELPS Chris #219 now doing chapter 8 PS just for fun - a stirring stick - 1/2" wide fails at 5 Kg and if its been used and got some epoxy on the 1/2 of the test span it fails at 11 Kg. Date: Mon, 2 Dec 1996 20:52:44 -0500 From: JQUESTCOZY@aol.com Subject: COZY: RAE 2426 and Fuel Hi all, Just a quick question that may have been answered before. I'm getting ready to cover my main spar and I understand that some of it will be exposed to fuel. Will RAE 2426 be ok exposed to fuel. (I plan on switching to the safety brand for fuel cells in strakes but hate to switch for just this layup if I don't need to). Thanks John Wilemski Date: Mon, 2 Dec 1996 21:27:05 -0500 From: DFinn7971@aol.com Subject: Re: COZY: RAE 2426 and Fuel In a message dated 96-12-02 20:56:46 EST, JQUESTCOZY@aol.com writes: << Will RAE 2426 be ok exposed to fuel. >> I'm not competant to answer the above question but I would like to throw out a thought I had awhile back (I posted it but got no response). I've heard a lot of sad tales of leaky fuel tanks and difficulties sealing the top of the strakes. Recently someone posted a note that the epoxy in the tank appeared to flake off (resulting in a crash). My question is, has anyone tried using a fuel cell? As a variation on this idea, I saw a roofing material on Bob Villa that was designed for flat roofs. It was a rubber membrane that was glued onto the plywood. I'm sure this material wouldn't work in a fuel tank but a similar material might. Would it be feasible to build the tanks, coat them with an adhesive and then attach the same material used for fuel cells. Is this an idea worth pursuing or am I just being fuelish? Dick Finn Cozy Mark IV #46 DFINN7971@AOL.COM Date: Tue, 3 Dec 1996 06:28:24 -0600 From: mbeduhn@mail.snider.net (Mark and Regina Beduhn) Subject: Re: COZY: RAE 2426 and Fuel > >Hi all, >Just a quick question that may have been answered before. I'm getting ready >to cover my main spar and I understand that some of it will be exposed to >fuel. Will RAE 2426 be ok exposed to fuel. (I plan on switching to the >safety brand for fuel cells in strakes but hate to switch for just this layup >if I don't need to). > >Thanks >John Wilemski > I called Nat with this same question before building my strakes, and he said that there was no need to switch epoxies. He said the reference to epoxy in the plans was from Burt Rutan's plans, and epoxies have improved their fuel resistance since then. He said any of the approved epoxies would be fine on the spar and in the tank. I would suggest calling him if you have doubts. Mark Beduhn Cozy MK IV #494 Installing the top skins on the strakes (last airframe component!) Date: Tue, 3 Dec 1996 10:31:35 -0500 From: CozyBldr@aol.com Subject: Re: COZY: RAE 2426 and Fuel In a message dated 96-12-02 20:56:46 EST, John Wilemski writes: << Just a quick question that may have been answered before. I'm getting ready to cover my main spar and I understand that some of it will be exposed to fuel. Will RAE 2426 be ok exposed to fuel. (I plan on switching to the safety brand for fuel cells in strakes but hate to switch for just this layup if I don't need to). >> I built my spar with 2426 too. My plan was to thoroughly sand the spar areas that will become part of the tanks and coat them with a few coats of 2427. I have decided to keep the plan but change the epoxy. I'm not yet sure as to which one just yet. Paul Stowitts Cozy Mark IV #200 From: "Jon Finley" Date: Mon, 9 Dec 1996 08:46:38 +0000 Subject: Re: Alcohol and epoxy dangers! > > 3) Alcohol seriously degrades almost all known epoxy, whether cured or > > uncured. Read this in strength, tensile, and elasticity abilities. I have used alcohol with STP and more recently West System. I have used the mix for filler only. I have found that it is MUCH easier to apply, is lighter, and easier to sand. I have not done any tests other than dropping tools on my structure but the filler seems to hold up to this type of abuse quite well. Jon Finley N54JF - 1835cc VW Quickie Bloomington, Minnesota Date: Thu, 19 Dec 1996 23:11:50 -0500 From: siegler@clark.net (Stuart Siegler) Subject: COZY: Cozy Epoxy: 2426/2177 Ratio Ok. I've started. I'm working on the first of the bulkheads, and already have a question: I have the Epolite 2426/2177 epoxy, which, on the can, lists a 4:1 by volume. Anyone know what it is by weight? I have this nifty digital scale that I'd like to use. Also, and hopefully before I *really start*, Ive seen the mail re: 2427, but nothing on 2426... were there comments that I missed? Thanks, Stuart -- Stuart Siegler Cozy Mk4 #575 Glued and tapered the seat back; God, have I got a long way to go. siegler@clark.net ssiegler@newvax.enet.dec.com http://www.clark.net/pub/siegler/ Date: Sun, 22 Dec 1996 21:47:59 -0500 From: siegler@clark.net (Stuart Siegler) Subject: COZY: Epoxy Worries Working on the first bulkhead, I measure out 100g of Resin(2426) and 21g of hardner (2177) [Thanks to Howard & Rob!], I notice that the Hardner is Purple. Purple Epoxy? I went ahead, and glassed the seatback, but before I go any further, I figured I check with you all. Also, How do you know how much to mix? Like I said, I started with 100g, and ended up making 3 more 100g... Is this just something you learn? Stuart -- Stuart Siegler Cozy Mk4 #575 Glued and tapered the seat back; God, have I got a long way to go. siegler@clark.net ssiegler@newvax.enet.dec.com http://www.clark.net/pub/siegler/ Date: Sun, 22 Dec 1996 22:11:30 -0500 From: Westlande@aol.com Subject: Re: COZY: Epoxy Worries In a message dated 12/22/96 6:56:48 PM, siegler@clark.net (Stuart Siegler) wrote: >Working on the first bulkhead, I measure out 100g of Resin(2426) and 21g of hardner >(2177) >[Thanks to Howard & Rob!], I notice that the Hardner is Purple. > > Purple Epoxy? Over the last five years, I have used several varieties of epoxy. The hardners almost always varied in color from lot to lot, especially the RAE hardener. Consequently, my project looks like a quilt in the shape of an airplane. Purple is a new color to me, but as long as it cures well and all, I wouldn't worry. It all gets painted later. -eric From: Marc J. Zeitlin Subject: COZY: Epoxy Worries (fwd) Date: Mon, 23 Dec 96 9:17:38 EST Stuart Siegler; >Also, How do you know how much to mix? Like I said, I started with >100g, and ended up making 3 more 100g... Is this just something you learn? I have found that you quickly get a feel for how much epoxy it will take to wet out various sizes and thicknesses of both UNI and BID glass. Better to mix up too little than too much (to avoid waste and exotherm), especially if you have a helper doing the mixing for you (I don't :-) ). Some people weigh their glass and then weigh the epoxy, going for an equal weight for both. I don't do this, but it would certainly put you in the right ballpark, since if you can achieve a 50:50 weight split in your layups, you're doing well. -- Marc J. Zeitlin Email: marcz@an.hp.com From: Strategic Systems Department Subject: RE: COZY: Aeropoxy details Date: Tue, 31 Dec 1996 10:45:14 -0500 Workability is similar to Safety Poxy. I was not pleased with the peel strength of the Aeropoxy. I did the bulkheads of my Long with Aeropoxy the glass did not adhere well to the micro. It would peel off with little or no foam coming with it. I am on the east coast so you may have different results. If you had good luck with the 2427, you will probably do OK with the Aeropoxy. Wayne Phillips a Long EZ builder in Va. had to scrap his center spar b/c the glass plies would peel off like peel ply. He used 2427. The 100 to 27 is correct. There are dimensions available for making a balance and also modifying the ratio pumps but I don't have them here right now. Howard Calk ---------- From: Epplin_John_A@hpmail1.90.deere.com[SMTP:Epplin_John_A@hpmail1.90.deere.com] Sent: Tuesday, December 31, 1996 10:07 AM Cc: cozy_builders@hpwarhw.an.hp.com Subject: COZY: Aeropoxy details Having used up my supply of 2427 epoxy and finding out it is no longer available, I ordered 4 gal of Aeropoxy 3660 / 2032. As I sort of expected it showed up with no documentation of any sort. Wicks catalog says mix at 100 to 27 by weight. I assume this is correct. If anyone has any pointers I would appreciate any comments. I was happy with the 2427 characteristics as far as workability. Is there any significant difference? John Epplin Je25272@hpmail1.90.deere.com Mk4 #467 starting wings. Thanks