Date: Sat, 20 Jan 96 09:08:55 From: jvasher@ic.net Subject: Instrument panel To Cut or Not! CH4 I currently do not have plans nor do I know if I have any idea of what I'm talking about but I will offer a suggestion on the instrument panel. It seems to me that waiting until you are ready to install the gages and radios would be the best bet. I would suggest that you buy yourself a 1/4 inch sheet of plywood and cut it to the size of the instrument panel then use that to cut all your holes into or radio slots but a little larger then the actual holes. (This way if you screw up you toss it out and start over) Then with a router and a straight cut bit with a collar as a guide you can mount the instrument panel in place then use the router to open the holes I'm pretty sure that a router bit will do a smoother job of cleaning the openings the a knife or saw will. If someone see's a problem please let me know. Thanks jvasher@ic.net a cozy builder wanna b' Date: Sun, 21 Jan 1996 19:12:52 -0800 From: Larry Jansch Subject: Chapter 4 Question O.K, what's the best tool/technique to cut the bulkheads out of the 0.2" hi-density foam? They're all traced out and I was going to use an Xacto knife saw and metal straightedge, but I figured it's best to ask the people who'd been there first. Thanks in advance! -Larry -- Cozy Mk.IV Plans #461 Still in Ch.4 From: Marc J. Zeitlin Subject: Chapter 4 Question (fwd) Date: Sun, 21 Jan 96 23:19:46 EST Larry Jansch writes: >O.K, what's the best tool/technique to cut the bulkheads out of the 0.2" >hi-density foam? They're all traced out and I was going to use an Xacto >knife saw and metal straightedge, Knife, or knive saw? The knife would be OK - don't know about the saw. I think that would be harder to cut accurately than using a blade, but I might be wrong - I've never tried the knife saw. I use a sharp utility knife and a straightedge to cut just about all of my foam, except for the 2" urethane (then I use a hacksaw blade). I usually take a couple of shallow swipes, rather than trying to get it all in one cut. YMMV (Your Mileage May Vary). -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Sun, 21 Jan 1996 23:28:08 -0500 (EST) From: Bill Walsh Subject: Re: Chapter 4 Question rarry Ifound using a power hand held jig saw with fine metalcutting blades at a med to high speed allowed me to cut acvcurately and right on the lines. Of course you are still going to have to mate the bulkheads to the sides so that should also be taken into consideration,that they don't have to be absolutely perfect right now. Any areas you a little off use a file to clean it up. Again as I said you will still have to fit them to the sides so don't get carried away spending too much time on perfection. MY 2 BITS ................BW > Date: Sun, 21 Jan 1996 19:12:52 -0800 > From: Larry Jansch > To: cozy_builders@hpwarhw.an.hp.com > Subject: Chapter 4 Question > > O.K, what's the best tool/technique to cut the bulkheads out of the 0.2" > hi-density foam? They're all traced out and I was going to use an Xacto > knife saw and metal straightedge, but I figured it's best to ask the people > who'd been there first. > > Thanks in advance! > > -Larry > -- > Cozy Mk.IV > Plans #461 > Still in Ch.4 > > > Date: Tue, 23 Jan 1996 11:58:16 -0700 (MST) From: "aka Mr. Radon" Subject: Re: using plans as a template isn't that a no no? (fwd) > >I went to a blueprint place > >and had them do dupe's of the drawings and then cut the copies and pasted > >on the patern material > > Just be careful with this, I had the same idea but when I got my copies back > decided to check them against the originals. Guess what, they didn't match. > The copies were off by about 4% in the X axis and maybe 7% in the Y axis. > I talked to the guys at the blueprint place about this, they said that it was > not possible to get EXACT reproductions with photographic type equipment, > and that bluelines were even worse. They told me the only way to get exact > copies is with offset printing, and that's terribly expensive (it suddenly > became > clear why the plans cost what they do). > > Just in case anyone isn't aware of it, Cad files are available in the > archives > of the bulkheads so if you have access to a good plotter you can get very > accurate drawings of these. I used the CAD files, they're great. If you do not have access to a plotter go to your nearest University or Community College, they will more then liklly have one. Act lost and ask if they have a plotter in one of their computer centers (most do). If you can load Windows on a PC you can figure out how to get the .DXF files to plot on their plotter. If you got problems, pick out a wiz kid and ask. If you get thrown out you tried and the next time (a week later), you won't have to ask as many questions. Trust me its worth the investment, not to mention its free! PS DIMENTION SEVERAL PARTS AND CHECK WITH A RULER TO INSURE 1"=1"!!!!!! ROY #503, Chapter 4 CU's Go-4, Hull layup Date: Wed, 24 Jan 1996 02:20:40 -0500 From: JHocut@aol.com Subject: Re: Chapter 4 Question >O.K, what's the best tool/technique to cut the bulkheads out of the 0.2" >hi-density foam? They're all traced out and I was going to use an Xacto >knife saw and metal straightedge, but I figured it's best to ask the people >who'd been there first. 1. Razor knife w/ straight edge for the straight portions, free hand for the curves. Make several passes using moderate force (too little and you'll never get fininshed, too much and you'll trash your work - voice of experience) 2. Rough cut w/ "Pizza Cutter" and final sand to size w/ course sandpaper. For some of the curved pieces this worked amazingly fast. 3. The xacto knife saw you've got may work pretty good also, I never got around to trying one (i.e. I don't own one yet and couldn't tear myself away from the project long enought to go out and buy one). Don't be afraid to experiment a little bit, if you screw a piece up it's only money. Jim Hocut Cozy IV # 448 Date: 24 Jan 96 10:41:44 EST From: Rick Roberts <102503.1561@compuserve.com> Subject: Re: Chapter 4 Question Greetings all, I have trouble understanding why there is so much communication on how to cut the foam for the bulkheads. The one tool which is almost indispensable is a battery powered jig-saw e.g. a makita you will use this for everything. It will cut anything on this airplane fast and accurately, even kevlar and graphite (where are these). Cutting with a knife is a pain in the posterior and not really safe. The knife will wander etc. From: Michael Antares Subject: RE: Chapter 4 Question Date: Wed, 24 Jan 1996 08:53:38 -0800 Greetings all, I have trouble understanding why there is so much = communication on how to cut the foam for the bulkheads. The one tool which is almost indispensable is a = battery powered jig-saw e.g. a makita you will use this for everything. It will cut anything on this airplane = fast and accurately, even kevlar and graphite (where are these). Cutting with a knife is a pain in the posterior and not really safe. = The knife will wander etc. Enjoy,=20 Rick =20 I invested in the best Bosch jigsaw I could find and I use it for a lot = of cutting, but for most foam sheets I have found that cutting with an = X-Acto knife against a straightedge is faster, straighter and does not = require any sanding after. One pass with the knife not pressing too = hard to set the line and a couple more to complete the cut. Even the = hardest foam cuts easily using a new blade (#11--not the small #10 = size). Curves I tend to cut with the jigsaw; I don't do well = free-handing with the knife. My two cents, Michael Date: Fri, 26 Jan 96 7:28:17 EST From: "Nick J Ugolini" Subject: Making templates for Chapt 4 I found using a template to be very easy and fast. I used this technique for all the bulkheads for chapt 4. A buddy of mine in Charleston,SC (Chuck Foster) is also building a Cozy and we mass produced the bulkheads cutting them out for both planes at the same setting. Check out Chuck's build time for chapt 4, on Marc's build page. Using 1/4 lauan plywood (very cheap) I cut the template to rough size. Lay the pattern on top of the plywood and using push pins, pin the template onto the plywood at each intersection of straight/curve lines. Remove the pattern. Mark a line between all the holes with a straight edge. Draw in the appropriate radiuses. I used a compass and soup cans. Cut out the template, then using a sanding block and a wood plane true up the lines. Along the centerline drill two alignment holes so you can flip the pattern (you only make 1/2 of the pattern and flip it for a mirror image.) When you make the part fiberglass part you can glass both sides at the same setting. Using the pattern, clamp it to the part. Drill a small hole through the alignment hole and pin the part to the template with a nail. Using a 1/4 in COLLET and a 1/4 in carbide cutter cut both sides at once. Do it outside with a mask, as it generates a lot of dust. Flip the template, put the nail through the alignment hole and route. Sound like a lot of work eh? It took me all of 45 min to cut all the parts for chapt 4. Routing them was very quick too. The parts fit EXACTLY to the sides of the plane. I feel that overall it is much quicker than traditional methods.... Nick U. ------------- Original Text >From jvasher@ic.net, on 1/20/96 9:25 AM: I was always told to use paper (which shrinks and expands as tempature changes) is a no no but yet I read in chapter 4 mailing list this occurs all the time. Can't you lay out on the foam using dimensions or is this not all that critical. Also, the impression I have gotten from what I'm reading that the bulk heads are flat serfaces layed glass on foam. if this is the case why not rough cut the foam to the size and then make up a plywood template to the actual size then use a router and a straight bit with a roller bearing to trim back to the proper size of the template. this would give some very clean edges.. (Or am I just making this tougher then it needs to be) Love to hear more oppinions on this... jvasher@ic.net Cozy Builder wanna b' 2 Date: Sun, 10 Mar 1996 22:24:05 +0000 From: Gary Buscombe Organization: Big Bear Online Subject: Oh Oh Larry In future layups make it easy on yourself and simply trim the excess glass/resin off with a razor knife when it cures in a few hours to the "rubbery" stage. Having to use a sabre saw is a bit too rough on the fragile glass. If I had to fix a delamination like yours, I would squirt some mixed resin underneath, then wrap additional layers around the area and squeegee/peel ply the repaired area. Secondly, you sound like you are using too much epoxy on your layups; try less and squeegee it more out to the edges, wetting it out, then wipe off the access before it cures. Also, laying down wax paper underneath makes things neater, too. Good luck! gbuscombe@bigbear.com Date: Sun, 10 Mar 1996 21:34:40 -0600 From: Larry Jansch Subject: Oh Oh HALP! I was trimming off the extra resin and glass on the fore face of F-28 using a sabre saw when I noticed that the corner of the glass layer was bouncing up and down along with the blade. It had peeled away from the foam on the tab-like projection on one end of the bulkhead. It has peeled back to about a distance of 2" or so from the end. It's not flopping around, it's just not attached to the core. (this is called "delamination" is it not?) How do I fix this? Squirt epoxy underneath? Or do I have to make another bulkhead? This specific problem isn't listed in the "Repairs" section.;-) While I'm at it, when microing and glassing one side of a bulkhead, how do you keep the micro/epoxy from oozing under the part and curing into an uglified mess on the other side? It did this in various spots on F-28 and I've been sanding it off. (yes, it did it on the "end tabs" as well) Thanks in advance ... and thanks for the continuing motivation to BUILD! -Larry Date: Mon, 11 Mar 1996 10:11:00 -0500 From: Dick.Finn@FNB.sprint.com Subject: Re: Oh Oh Larry, I suggest you try trimming the glass with a utility knife after it cures for a few hours rather then using a saber saw. For repair, I would mix up some micro, peel back the lamination, squirt in the micro and then lay a piece of Saran wrap over (and under) the part and weight it down until it cures. If the glass itself is damaged you could lay up additional layers. I've had some trivial amount of epoxy leaking under the foam but have been able to easily sand it off. It occurs to me that an easy solution would be to put some masking tape around the edges on the bottom side. If you are getting a real lot of this you may be using too much epoxy. Try putting it on a little at a time, squeegee it in and add more untill you get the cloth thouroughly covered. Dick Finn Cozy Mark IV #46 ______________________________ Reply Separator _________________________________ Subject: Oh Oh Author: ljansch@ix.netcom.com at INTERNET Date: 3/10/96 11:27 PM HALP! I was trimming off the extra resin and glass on the fore face of F-28 using a sabre saw when I noticed that the corner of the glass layer was bouncing up and down along with the blade. How do I fix this? While I'm at it, when microing and glassing one side of a bulkhead, how do you keep the micro/epoxy from oozing under the part and curing into an uglified mess on the other side? It did this in various spots on F-28 and I've been sanding it off. (yes, it did it on the "end tabs" as well) Date: Wed, 29 May 1996 01:01:25 -0400 From: Lenpilot@aol.com Subject: COZY: Front Seatback notches Hello Fellow builders, My name is Leonard Farneth, I live in Fredericksburg Va. I have been watching this group and reading all the mail since early march 96. I purchased plans # 522, part of my decision was based on the fact that this group exists. Now that the foam, epoxy and fiberglass cloth are starting to take up a lot of space, And after finishing the bookend, enlongated ravioli, (confidence layup :<) ) Etc. I have finally started to build the first peice of the actual airplane, The front seatback. Heres my problem When you have cut out the notches in the front seat back, and are ready to layup the one ply of bid on the backside, do you cover the cutout areas (notches in the sides cut from the templates) with the one layer of bid, or leave them for later. the templates have very abrupt corners this makes me wonder weather or not they should be left to finish when the sides are mated to the fuselage, or filled in now. I looked in the archives for chapter 4 E-Mail but couldn't find anything relating to this. I thoroughly enjoy recieving e-mail from this group. I want to thank you in advance for your help. I am sure this will be the first of MANY questions I have in the building process. Leonard Farneth lenpilot@aol.com From: ratencio@coastalnet.com Date: Wed, 29 May 96 10:05:53 Subject: Re: COZY: Front Seatback notches In <960529010124_544583744@emout15.mail.aol.com>, on 05/29/96 at 01:01 AM, Lenpilot@aol.com said: >When you have cut out the notches in the front seat back, and are ready >to layup the one ply of bid on the backside, do you cover the cutout >areas (notches in the sides cut from the templates) with the one layer of >bid, or leave them for later. Leonard, I am just finishing up the last couple of pieces in chapter 4 and what I did on the seat back is to not glass over the upper cutouts, but I did glass over the smoother, lower cutouts and the straight edges. I'm not sure just how much strength you get by glassing over the cutout. I believe the way the bulkheads are attached to the fuselage sides, loads are transfered through the outer skin and whether the edges are glassed or not is not a big player in the loads tranfer. I'm sure that if I'm way off the mark on this one, someone wiser than myself will inform both of us. That's the great thing about this forum. ----------------------------------------------------------- Rob Atencio Cozy Mk IV #496 New Bern, NC E-Mail: ratencio@coastalnet.com ----------------------------------------------------------- Date: 29 May 96 10:13:44 EDT From: "William E. Buckley" <74744.2301@compuserve.com> Subject: COZY: Front Seatback notches Leonard Farneth wrote >When you have cut out the notches in the front seat back, and are ready to >layup the one ply of bid on the backside, do you cover the cutout areas >(notches in the sides cut from the templates) with the one layer of bid, or >leave them for later. We've all wondered about this one when we started. The answer is, no. None of the notches or the holes through the bulkheads get glassed. Knife trim at the edges. The consensus seems to be (for the thin bulkheads, inst panel, F22, etc.) to go back some time later and rout out 1/8 in of foam and micro around the edges. Keep on truckin. William E. Buckley (Cozy Mk IV, #437, Chap 9) 74744.2301@compuserve.com Date: Wed, 29 May 1996 12:03:00 -0400 From: Dick.Finn@FNB.sprint.com Subject: Re: COZY: Front Seatback notches --OKknGgvMIkm39MOiB7mxIZv5uv2IRBba Content-type: text/plain; charset="us-ascii" Leonard, There are several parts that end up having bare foam edges. The notches in the seat are a good example. Other examples are the leg holes in the instrument panel and the edges of various bulkheads. In virtually all cases you do not glass edges unless specifically called for. Off the top of my head I can't think of a case where glassing an edge was called for however. In some cases where the foam edge would be exposed after finishing, such as the leg holes in the instrument panel many (most?) builders route out the foam and fill in with micro to give a good finish and improve durability. Dick Finn Cozy Mark IV #46 DICK.FINN@FNB.SPRINT.COM ______________________________ Reply Separator _________________________________ Subject: COZY: Front Seatback notches Author: owner-cozy_builders@hpwarhw.an.hp.com at INTERNET Date: 5/29/96 2:40 AM When you have cut out the notches in the front seat back, and are ready to layup the one ply of bid on the backside, do you cover the cutout areas (notches in the sides cut from the templates) with the one layer of bid, or leave them for later. Leonard Farneth lenpilot@aol.com --OKknGgvMIkm39MOiB7mxIZv5uv2IRBba Content-type: text/plain; charset="us-ascii" --OKknGgvMIkm39MOiB7mxIZv5uv2IRBba-- Date: Sat, 1 Jun 1996 13:33:12 -0400 (EDT) From: Randy Crutfield Subject: COZY: Landing gear hardpoints I was going through a weeks worth of messages last night and remember someone asking about peelplying the hardpoint layups for the landing gear bulkheads. I'm not sure why you would want to do this. If the layup is done on a plastic film, the resulting surface is very smooth and very easy to dull with 36 grit sandpaper. I applaud those of you who were able to use Saran Wrap. I tried a number of times and just couldn't get it to lay down right. I now use bagging film that is intended for vacuum bagging before I make a flat layup, or as a backing surface for wetting out tapes. I am a member of the "Three Times Before it was Right" fuel valve mounting bracket club and am also a member of the "Three Times Before it was Right" hardpoint layup club. My first layup was obviously resin rich. The thick areas could be seen when looking at the edge after cutting. It measured 0.3". Thought I did a better job on the second one, but it was still slightly too thick, (0.29"). Checked back in the plans and noted on page 3-8 that each layer of BID builds up to 0.013". 22 layers of BID works out to be 0.286", very close to the thickness of my second layup. Wrote Nat after that and he replied that the intent was to get a layup that is 1/4" thick and that the number of layers of glass could vary to achieve this thickness, but that he thought the numbers that he called out in the plans should work if heavily weighted. He also mentioned that 18 to 19 layers should work if you don't use a weight. Armed with this knowledge and some additional thoughts about the subject the third attempt was begun. On the third attempt, I squeegied very carefully between layers, and stopped every 5 layers, applied a piece of bagging film over the layup and squeegied the devil out of it. Removed the bagging film and started adding layers again. This obviously removed any excess resin, the next layer after the "devil squeegeeing" always took a lot of resin to wet out. After finishing with all 22 layers that Nat calls for, I added a piece of bagging film to the top layer followed by a piece of plywood and finally a few concrete blocks. The result was perfect. Hope that this helps someone who has yet to attempt this feat. Randy Date: Mon, 3 Jun 1996 16:42:36 -0600 (MDT) From: "aka Mr. Radon" Subject: COZY: Landing Gear Hard Points I've been reading lately the problems with laying up the landing gear hard points and getting the correct layers and thicknesses. What if I told you that there was some magical material out there that is exactly .25" thick, comes in sheets and has over 35 layers of pressure formed BID? Well the stuff is called G-10, and is available at your local plastics shop; not store, but industrial plastic shop. I called Nat on this one and he's not against using it, he did mention he has never heard of it. We did testing on this stuff at school. The material is about three times stronger then the 22 ply layup indicated in the plans. The only drawback to using G-10 is it eats band saw blades! I bought enough material for the hard points from a scrape bin, it was around $10. It normally costs about $17 a square foot. If you can not find it, let me know and I could mail a square foot for about $20. Considering the time and material savings it may be worth it. ROY ============================================================================= Roy H. Grossinger- ME grossinr@rastro.colorado.edu Cozy Mk IV #503; Chapter 4 ROY_GROSSINGER@Radon-hq.ccmail.compuserve.com CU's Go - 4; Hull Layup "A man's destiny is his character" | ___ | http://bechtel.colorado.edu/~grossinr |---------(>-<)---------| http://www.abwam.com/grossing / ~~~ \ o/ \o Date: Wed, 5 Jun 1996 17:54:39 -0400 (EDT) From: Randy Crutfield Subject: Re: COZY: Front Seatback notches If you decide to leave the foam in place, glass the seatback and then cut out the notches, be careful as you cut. If your blade is too coarse, you will probably delaminate the glass from the foam at the edge of the cut. Consider using a hacksaw blade instead of your sabre saw. Randy Date: Thu, 6 Jun 1996 20:14:26 -0400 From: PBurkha238@aol.com Subject: Re: COZY: Front Seatback notches In a message dated 96-06-05 18:01:06 EDT, you write: >If you decide to leave the foam in place, glass the seatback and then cut >out the notches, be careful as you cut. If your blade is too coarse, you >will probably delaminate the glass from the foam at the edge of the cut. >Consider using a hacksaw blade instead of your sabre saw. >R Better yet use a circular cutting disc on a dremel , I use this to cut all but the toughest of glass . Paul Burkhardt by mta bnr.ca in /PRMD=BNR/ADMD=TELECOM.CANADA/C=CA/; Relayed; Thu, 13 Jun 1996 22:50:59 -0400 by /PRMD=BNR/ADMD=TELECOM.CANADA/C=CA/; Relayed; Thu, 13 Jun 1996 22:49:39 -0400 by /PRMD=BNR/ADMD=TELECOM.CANADA/C=CA/; Relayed; Tue, 11 Jun 1996 22:49:00 -0400 Date: Thu, 13 Jun 1996 22:49:00 -0400 [/PRMD=BNR/ADMD=TELECOM.CANADA/C=CA/;bcars735.b.115:14.05.96.02.49.39] From: "michael (m.j.) anderson" Subject: COZY: Engine Mount Hardpoints I was working on the firewall and was in the process of installing the alum. hardpoints for the engine mounts. The plans, drawings, and newsletter updates did not mention of using 5 min. epoxy or flox to set the hardpoints. All I did was tapped them in with a hammer and they are snug. Is this what everyone else has done? Thanks, Michael Anderson mikej@nortel.com Cozy Mark IV #484 Date: Fri, 21 Jun 1996 15:35:52 -0400 From: StetsonE@aol.com Subject: Re: COZY: chapter 4 - air in the laminate In a message dated 96-06-19 10:43:19 EDT, William Kleb wrote: >after the lay-up was finished, i checked it carefully and saw no air >bubbles or dry glass fibers. i put a sheet of peel-ply over the entire >thing, adding just a little more epoxy. when it cured, it had air in >the glass fibers covering around 20% by area. i rejected the part. > >i have since tried a test lay-up, adding lots of epoxy and using a lot >of micro on the foam: it looks even worse. during this same period of >time, i have laid-up the stiffners on the instrument panel without >difficulties. I've used Safe--T-Poxy (STP) I and II exclusively throughout my Long-EZ project. Personally, I like STP II a little better because it seems to wet out better/faster than STP I, but it'll get thick in the cup a little faster than STP I. This isn't a problem once the epoxy is on the part. It's my understanding that humidity isn't an issue with STP. Rutan just recommends "not to do layups when it's pouring down rain outside" with STP. I've found that many builders greatly underestimate the importance of both shop temp and epoxy temp when doing layups. This is especially important when you're starting out because you haven't yet developed the varied layup techniques you'll need when the temps aren't ideal. STP (and probably the other epoxys) are a whole different animal when temps aren't perfect and the stuff requires different layup techniques at cooler temps. The glass is slow to wet out, entrapped air doesn't want to come out, extra epoxy resists being squeeged out without disrupting your glass fibers, and you'll end up with heavier parts. 80 degree shop temp is good, but I like 90-100 degrees in my epoxy hot box. If you don't have your pump in an insulated box or container, do so, or at least put a light bulb under the resin container of your pump for an hour or so before starting a layup. Don't keep these temps in your hot box all the time because it tends to "age" the hardner faster (gets dark quicker). Just bring the temp up in the hot box a couple of hours before a layup. Also purchase a kerosene space heater. Costs about $150.00 and it'll raise the temp of my 2 car garage 20 degrees in about an hour. The brand I have is a Corona. Personally, I won't do a major layup (over a 6 sq ft) without getting both shop temp between 80-90 and epoxy temp 90-100. If anyone thinks I'm overestimating the importance of this, before you flame me, try it my way and see the difference. A mere 10 degree difference will make the glass wet out in a third of the time, your squeegee will glide over the part instead of drag, and the layup will take 1/2 the time and 1/10 the frustration/hassle. Using these temp recommendations, with the assistance of 2 other people, I glassed each side of my wing surfaces in 4 hours per side, and the part weight for each whole wing was WITHIN A POUND of what Rutan said it should be. In contrast, it took my wife and I twelve hours to glass EACH side of my fuselage with shop temp at 68-70 and epoxy at 80. That layup was acceptable, but way to rich in epoxy. The work/frustration was unbelievable. The fuselage weighed 5 pounds more than what Rutan said it should have. One other thought. If your problem is flecks of air in the top ply instead of air bubbles at the foam level, you probably either squeegeed a little to aggressively, or didn't add enough epoxy when adding the peel ply. The peel ply pulled the epoxy it wanted out of the top ply. Assuming you have the correct resin/glass ratio on the part, you should ALWAYS add epoxy to wet out peel ply. If you know the part is rich in epoxy, then peel ply without extra epoxy is ok. Using thickened/cold epoxy with peel ply, add the extra epoxy to the layup first, then add the peel ply. Once the peel ply starts to wet out, squeege off the excess. Or, alternatively, paint on a coat of epoxy on the peel ply first, then apply it epoxy side down on the layup, then squeegee/stipple. It wets out almost instantly. With fresh epoxy at the recommended temps, the peel ply will wet out beautifully by adding the peel ply first, then a little extra epoxy, and a little squeeging. Last thought - If the part is dimensionally correct, and meets Nat's layup acceptability criteria, use it, even if the part isn't pretty. I also rebuilt my back seat bulkhead. It had some air bubbles which I could have filled with injected epoxy, and a dry area in the top ply that wasn't pretty but was OK by RAF's criteria. After showing the rejected part to an experienced builder, he said if he rejected parts like that he would have never finished his plane. I didn't heed his advice for many years. His plane was finished in 4 years, and I'm at 11 years and counting. Enough said. My opinions anyway. Stet Elliott stetsone@aol.com Perpetual Long-EZ builder Date: Sun, 23 Jun 1996 12:36:20 -0400 From: "Douglas O. Powell" Subject: COZY: Bulkhead boo-boo, Advice? Well I'm not even done with Chapt. 4 yet, and have already made a mistake (no doubt the first of many). I started laying up the landing gear bulkheads on .200" Last-a-foam (Clark replacement), instead of the .250 H100 PVC specified. I was wondering why my hardpoints appeared to be too thick. Turns out they are correct and the foam is too thin. Is this a do-it-over type mistake, or will the bulkheads be acceptable with the substitute foam? I feathered the steps at the hardpoint edges with micro to avoid kinks in the glass fibers. The last-a-foam is 18 lb/cu ft vs 6 lb/cu ft for the specified PVC. Only problems I can see are slightly lower bulkhead stiffness (is this enough to worry about?), and a little extra weight from the higher density foam (less than 1.5 lb). All advice will be considered. Thanks, Doug Powell Cozy MK-IV #293 powelldo@ix.netcom.com Date: Sun, 23 Jun 1996 14:41:45 -0700 From: Michael Antares Subject: COZY: Bulkhead boo-boo, Advice? This is an interesting question in that, for me, it brings up a deep philosophical issue about building the Cozy, one that I have faced several times as I'm sure most builders have also. I personally don't think the boo-boo will seriously affect the form, fit or function (as the saying goes) of those bulkheads. I don't however speak with technical authority. It's just my overall engineering sense that says those bulkheads are subsequently integrated into the structure so thoroughly with several more layers added in different areas that the .050 difference in thickness will be relatively unnoticeable. However, here is my dilemma. At this stage of construction it is a rather easy boo-boo to correct. As a proportion of what you have already done that may not seem to be true but in the context of overall construction time, it is microscopic. My general philosophy has been to bite the bullet and do it the right way unless the correction time and expense is overwhelming in comparison to the benefit derived. I don't think you want to consider this the first of many boo-boos. Every time I have done something over it has re-emphasized the need to read, then re-read then build it in my mind before actually doing the work. I am in constant dread of making THE boo-boo, the one I HAVE to do over, the one that costs lots of time and money, the one that shows me how dumb I really am. So I tend to not accept small mistakes even though I could so as not to get in the frame of mind that might lead to doing the BIG one. So far it has paid off... My two cents, 6077 Old Redwood Highway Penngrove CA 94951 707.664.1171 Finished through chap 14 except chap 13. Currently on 16, 17 and 24. Date: Sun, 23 Jun 1996 18:34:35 -0400 From: Lenpilot@aol.com Subject: COZY: Drawings I came across an easy and quick way to transfer the drawings onto the foam without cutting them up or spending a great deal of time tracing. I thought I would share it with you guys in the event someone else may benifit. I used a Serrated Tracing Wheel (available at any good sewing suplies store I got mine for a dollar and twentyfive cents) It is a 3/4 inch wheel on an axle at the end of a 6" plastic rod. it looks like a small saw blade. what it does is cut a perforation in the lines on the drawing and into the foam below. You follow the lines as though you were tracing, then lift the drawing off, and there it is on the foam, little dots about 1/32" apart you can then fill in with a pencil or simply cut. Heres the good part.. Since it leaves the preforation in the drawing, If you need to re-use the drawing later, all you have to do is take an old stocking (panty hose etc.) fill it with chalk (from a chalk line) and pin down the drawing on the foam & then using the stocking full of chalk, pat it on the preforation. using this method the chalk goes through the preforation onto the foam and you can then pencil it in and cut. With all the talk of preserving the drawings lately I thought this might come in handy. it does put pinholes on the drawings but it is a lot less time consuming than other methods and leaves the drawings in a usefull state. I finally tried it myself today. It works perfectly and saves a lot of time. I learned this trick from a signmaker I went into partnership with a while back, I never made a dime, (In fact I lost money) But This was the method he used to reuse expensive sign template drawings. Its good to finally get something back from that!!! Try this on some scraps first it works great :-) thre manufacturer for the tracing wheel is Prym Dritz Corporation Spartanburg SC 29304 If anyone wants one and can't find one E-Mail me and I will go to my local store and get some and send you one. Leonard Farneth lenpilot@aol.com From: Marc J. Zeitlin Subject: COZY: Bulkhead boo-boo, Advice? Date: Mon, 24 Jun 96 9:28:20 EDT Doug Powell writes: >Well I'm not even done with Chapt. 4 yet, and have already made a mistake >(no doubt the first of many). I started laying up the landing gear >bulkheads on .200" Last-a-foam (Clark replacement), instead of the .250 H100 >PVC specified...........Is this a do-it-over >type mistake, or will the bulkheads be acceptable with the substitute foam? I would tend to agree with Michael Antares on both counts - first, this is PROBABLY not critical - I've installed all the bulkheads in the fuselage and installed the main gear as well, and I can't think of anywhere where this 0.050" would matter. However, it's pretty easy to fix, and then you won't have to worry about it anymore. I'd say, do it over for the peace of mind and the practice - as Michael said, it's only a few hours. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Mon, 24 Jun 1996 12:30:38 -0600 (MDT) From: "aka Mr. Radon" Subject: Re: COZY: Bulkhead boo-boo, Advice? > those bulkheads are subsequently integrated into the structure so thoroughly > with several more layers added in different areas that the .050 difference > in thickness will be relatively unnoticeable. I would also have to agree with the full content of this message, if you know you made a Boo-Boo, and you are going to fly the airplane, and you didn't fix it, your always going to have that question in the very back of your mind. If you are in this to have a safe plane, always incur the extra time and expense to do it right, even if it isn't the first time. Also, as written above, if it was .05" I wouldn't mind, but it is really 0.5". That when looked at isn't all that bad since he did feather the change with micro, I would have used flox since its has better material qualities, this is a landing gear bulkhead and it needs to transmit the landing forces to the aircraft hull. That .5" is 20% of the area and when you think of it in those terms I'd get that nagging feeling in the back of my head. ROY ============================================================================= Roy H. Grossinger- ME grossinr@rastro.colorado.edu Cozy Mk IV #503; Chapter 4 ROY_GROSSINGER@Radon-hq.ccmail.compuserve.com CU's Go - 4; Hull Layup "A man's destiny is his character" | ___ | http://bechtel.colorado.edu/~grossinr |---------(>-<)---------| http://www.abwam.com/grossing / ~~~ \ o/ \o Date: Mon, 24 Jun 1996 12:35:03 -0600 (MDT) From: "aka Mr. Radon" Subject: COZY: Opps! Darned, I hate it when you send something and then want to race back to the mail box. I know its .05". Darn little decimal places, still it is 20% of foam thickness. Sorry, ROY ============================================================================= Roy H. Grossinger- ME grossinr@rastro.colorado.edu Cozy Mk IV #503; Chapter 4 ROY_GROSSINGER@Radon-hq.ccmail.compuserve.com CU's Go - 4; Hull Layup "A man's destiny is his character" | ___ | http://bechtel.colorado.edu/~grossinr |---------(>-<)---------| http://www.abwam.com/grossing / ~~~ \ o/ \o From: Marc J. Zeitlin Subject: Re: COZY: Bulkhead boo-boo, Advice? Date: Mon, 24 Jun 96 14:43:13 EDT Roy Grossinger wrote; > Also, as written above, if it was .05" I wouldn't mind, but it is really >0.5". Um, check the math: 0.250" - 0.200" ========= 0.050" >.......... That .5" is 20% of the area True, but... >.......... and when >you think of it in those terms I'd get that nagging feeling in the back of >my head. Unless the bulkhead is in bending, the foam does nothing other than help prevent buckling of the skin. In the case of the landing gear bulkheads, it's hard to imagine a situation where that 0.050" will matter. The consensus recommendation (with three votes in :-) ), however, is clearly to fix it. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Mon, 24 Jun 1996 14:40:59 -0500 From: graf@ectss2.jsc.nasa.gov (Jonathan Graf) Subject: COZY: Re: Bulkhead boo-boo, Advice? Douglass, I'd have to ring in on this issue that the part needs to be re-made, not simply because it would be cheap, easy and done in a realatively short period of time as has been asserted before by other respected members of this builder list. The reason is that even though the foam thickness is only 0.05" different, most of the parts made on the composite airplane designs are based on the same ideas that make I-beams such a nifty idea and that is the web (or foam here) simply holds the load carrying ends (or glass here) in place. This means that the part will be weaker by roughly a function of the distance between the glass (i.e. foam thickness), in this case ~20% (Ref. Mr. Radon), that it is reduced by. That may not mean much for the bid and horizontal uni layups that are done, but it will be significant for the multiple (~7-8) diagonal uni layups that cover the gear hard points. Even though Nat says in his plans that the Cozy composite design is significantly stronger than needed, the small amount of time and effort and need to have solid landing gear bulkheads outweighs the cost savings. My $0.02. Jonathan Graf graf@ectss2.jsc.nasa.gov From: Marc J. Zeitlin Subject: COZY: Re: Bulkhead boo-boo, Advice? Date: Mon, 24 Jun 96 16:02:22 EDT Jonathan Graf wrote: >........ This means that the part will be weaker by roughly a >function of the distance between the glass (i.e. foam thickness), in this >case ~20% (Ref. Mr. Radon), that it is reduced by. As I stated before, this would only be true if the bulkhead had BENDING loads applied to it, like so: F1 \/ ----------------------- bulkhead | | ----------------------- /\ /\ F2 F2 Or something similar. In this case, the glass on the top would be in compression and the glass on the bottom in tension (like the wings). Then, the distance between the top and bottom fibers would have a large effect on the stresses and stiffness of the structure (and you'd also have a shear web to carry the stresses between the top and bottom, because the foam is nowhere near strong enough to do it - that's why there's a shear web in the wings, spar, and canard). What we actually have in the case of the landing gear bulkheads is: ----------------------- bulkhead F1<--- | | --->F1 ----------------------- In this case, the glass on both sides is either in tension or compression, depending on whether F1 is positive or negative. In either case, however, the distance between the fibers is not important, since ALL of the stress is carried by the glass, not the foam (well, 99.99999% anyway). For these bulkheads the foam merely supports the glass so that it doesn't buckle under compressive loads (like trying to push a string). Still, make them over :-). -- Marc J. Zeitlin Email: marcz@an.hp.com From: RJMANC@cris.com Date: Tue, 25 Jun 1996 00:50:51 -0400 (EDT) Subject: COZY: Bulkheads Just to let you know up front... I very new at this and this is pobably a very simple question... But I can't seem to find an answer in the manual or other books I have.... In chapter 4 Nat says you may have to 5 min epoxy 2 pieces of stryo together. Well my question is this in the manual it says when putting 2 pieces of stryo together use micro.. Which one do I use and exactly how ?? I have 2 pieces that need to bond end to end.. do I use 5 min epoxy on both pieces and no micro or micro the length of each and use 5 min to help hold it togther !!! I know this is probably a very basic question but I don't want to make any mistakes... Thank you Robert Mancuso (#537) Date: Tue, 25 Jun 1996 08:21:37 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: COZY: Re: Bulkhead boo-boo, Advice? >Jonathan Graf wrote: > >>........ This means that the part will be weaker by roughly a >>function of the distance between the glass (i.e. foam thickness), > in this >>case ~20% (Ref. Mr. Radon), that it is reduced by. Are we forgetting that 18 lb foam was used instead of 6 lb foam. this change in pounds per inch will normally mean more strength with less thickness??? The further we separate inner to outer skins the stiffness will go up that we see from the glass. To get the same stiffness with thinner cores, you must go to a higher density. I think the main gear bulkheads would be stronger in this case out of 18 lb last-A-foam. my 2 bits AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com From: Marc J. Zeitlin Subject: COZY: Bulkheads (fwd) Date: Tue, 25 Jun 96 8:29:09 EDT Robert Mancuso writes: > In chapter 4 Nat says you may have to 5 min epoxy 2 pieces of stryo >together. Well my question is this in the manual it says when putting 2 >pieces of stryo together use micro.. Which one do I use and exactly how ?? I >have 2 pieces that need to bond end to end.. do I use 5 min epoxy on both >pieces and no micro or micro the length of each and use 5 min to help hold >it togther !!! In a situation like this, the 5 minute epoxy is more than adequate. While it is true that you should use micro for bonding two pieces of foam together (such as the canard or wing or winglet cores) you will have many situations where you are trying to make one big flat piece of foam out of a bunch of small ones (like the bulkheads and fuselage sides). In these cases, 5 minute epoxy is fine (the plans tell you what's OK to use - when Nat says that you may have to use 5 min epoxy to join two pieces of foam, he's just telling you that your foam pieces may not be quite big enough). When you MUST use micro, the plans will call it out, or at least not say anything about an alternative. For the big flat parts, once you squeegee micro on the surface and glass it, you've got all the strength you would have had by microing along the narrow edge. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Tue, 25 Jun 1996 13:06:23 -0600 (MDT) From: "aka Mr. Radon" Subject: Re: COZY: Bulkheads (fwd) On Tue, 25 Jun 1996, Marc J. Zeitlin wrote: > Robert Mancuso writes: > > > In chapter 4 Nat says you may have to 5 min epoxy 2 pieces of stryo > >together. Well my question is this in the manual it says when putting 2 > >pieces of stryo together use micro.. Which one do I use and exactly how ?? I > >have 2 pieces that need to bond end to end.. do I use 5 min epoxy on both > >pieces and no micro or micro the length of each and use 5 min to help hold > >it togther !!! > > In a situation like this, the 5 minute epoxy is more than adequate. > While it is true that you should use micro for bonding two pieces of foam > together (such as the canard or wing or winglet cores) you will have many > situations where you are trying to make one big flat piece of foam out of > a bunch of small ones (like the bulkheads and fuselage sides). In these > cases, 5 minute epoxy is fine (the plans tell you what's OK to use - when > Nat says that you may have to use 5 min epoxy to join two pieces of foam, > he's just telling you that your foam pieces may not be quite big enough). I have found that 15 minute epoxy works real well in some places where the extra time is really needed such as large pieces. I've also done vacume bagging of all my parts so far and found that if you fill holes or other imperfections with 15 minute micro the micro is not sucked up into the fiberglass layups. We found this out the hard way on CU's Go-4 project when we used 2410 micro to fill out a few holes, had to redue the whole part. ROY From: RJMANC@cris.com Date: Tue, 2 Jul 1996 23:28:51 -0400 (EDT) Subject: COZY: M Drawings Ok !! What is the best way to transfer the M drawings to the foam ? I'm looking for an acurate simple way to do this... Can anyone help on this ?? Thank you Robert \______OO______/ | | O O #537 From: Marc J. Zeitlin Subject: COZY: M Drawings (fwd) Date: Wed, 3 Jul 96 9:09:27 EDT Robert Mancuso (although you wouldn't know that from his post :-) ) wrote: > Ok !! What is the best way to transfer the M drawings to the foam ? I'm >looking for an acurate simple way to do this... Can anyone help on this ?? Well, there's a bunch of ways, some of them posted just recently. I'll list the ones I can think of in no particular order. 1) Cut out the drawings with a scissors and paste on the foam. (this obviously ruins the drawings). 2) Lay the drawings on the foam and poke holes every 1" with a sharp pencil, then connect the dots on the foam 3) Use a sewing needle roller thing (that's the technical name - oh, wait, Leonard Farneth [see archives for chapter 4, June 23rd] says it's a Serrated Tracing Wheel) to trace the drawing onto the foam (easier than #2) 4) Make accurate Xerox copies and then use them for #1 -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Wed, 3 Jul 1996 12:42:42 -0600 (MDT) From: Roy Grossinger Subject: Re: COZY: M Drawings (fwd) > Robert Mancuso (although you wouldn't know that from his post :-) ) > wrote: > > > Ok !! What is the best way to transfer the M drawings to the foam ? I'm > >looking for an acurate simple way to do this... Can anyone help on this ?? > > Marc wrote.... > > Well, there's a bunch of ways, some of them posted just recently. I'll > list the ones I can think of in no particular order. > > 1) Cut out the drawings with a scissors and paste on the foam. (this > obviously ruins the drawings). > > 2) Lay the drawings on the foam and poke holes every 1" with a sharp > pencil, then connect the dots on the foam > > 3) Use a sewing needle roller thing (that's the technical name - oh, > wait, Leonard Farneth [see archives for chapter 4, June 23rd] says > it's a Serrated Tracing Wheel) to trace the drawing onto the foam > (easier than #2) > > 4) Make accurate Xerox copies and then use them for #1 > 5) Download the .DXF files made by Lee Devlin, and take them to a local University. Find out if they have a ploter and CAD software, and print them out. I know lots of Non-University people who use the Universities equipment and I've never seen them check ID's. I found these drawings to be right on, and easy to use. However, if you are not familar with a CAD program or computers it may be more effort then other methods. ROY ============================================================================= Roy H. Grossinger- ME grossinr@rastro.colorado.edu Cozy Mk IV #503; Chapter 5 ROY_GROSSINGER@Radon-hq.ccmail.compuserve.com CU's Go - 4; Hull Layup "A man's destiny is his character" | ___ | http://bechtel.colorado.edu/~grossinr |---------(>-<)---------| http://www.abwam.com/grossing / ~~~ \ o/ \o Date: Thu, 4 Jul 1996 06:54:06 -0700 From: blairhlm@ix.netcom.com (Blair Hileman) Subject: Re: COZY: M Drawings >looking for an acurate simple way to do this... Can anyone help on >this ?? Try legal size carbon paper sheets between template and foam, trace with blunt tool, transfers entire outline exactly. When you need mirror image of template (F-28, etc.), use second piece of carbon paper with the carbon side up at the same time to transfer outline to back of template, flip template over, use as above. Blair Hileman blairhlm@ix.netcom.com Date: Thu, 4 Jul 1996 19:35:33 -0700 From: wkasty@ix.netcom.com (william g kastenholz) Subject: COZY: firewall layup chapter 4 I'm ready to layup the firewall one layer of BID but i've never read how to prepare a wood surface either in the plans or elsewhere. Bill Kastenholz wkasty@ix.netcom.com Date: Thu, 04 Jul 1996 21:23:03 -0700 From: Michael Antares Subject: COZY: firewall layup chapter 4 I just soaked the wood well with epoxy and then did the layup (after giving the wood a good sanding). I didn't do a micro--maybe others have. Michael 6077 Old Redwood Highway Penngrove CA 94951 707.664.1171 Cozy#413 Finished through chap 14 except chap 13. Currently on 16 and 24. From: Marc J. Zeitlin Subject: COZY: firewall layup chapter 4 (fwd) Date: Fri, 5 Jul 96 18:38:00 EDT Michael Antares wrote: >I just soaked the wood well with epoxy and then did the layup (after giving >the wood a good sanding). I didn't do a micro--maybe others have. I just laid the glass up on the dry plywood. The layup came out a little dry, so Michael's method would probably be better. I believe you are NOT supposed to put micro between the wood and the glass, although for the life of me I can't remember where I heard this. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Fri, 5 Jul 1996 23:09:03 -0400 From: Lenpilot@aol.com Subject: Re: COZY: Landing Gear Hard Points For those just starting out, Roy Grossinger has found a great product called G-10 It is the Landing gear hard points from Heaven. The stuff is perfect and exactly a Quarter inch thick. It is described below in his June 6 posting. It fits like a glove (not OJ's), is strong as an ox, and is easy to cut (if you use a fiberglass cutting blade for your jigsaw). I ordered enough (from Roy,( Thank you Roy)) to get all the hard points. after I cut and installed them, I realized there was no way I could come anywhere close to the structural integrity of this product. I called Nat on an unrelated subject, While I was on the phone with him I asked about this product, And he was all for it. I asked him if I could post his opinion, He said most definately, and that the only reason he hadn't included it in the newsletter was because he ran out of time before publishing. I expect he will include a note about this in the next newsletter. In the meantime This is a great product, approved by Nat, and I want to thank Roy for sharing it with us. It has certainly sped the production of my plane, as well as enhanced the quality. I look foward to many other inovative ideas from members of this group. Thanks Roy, Leonard Farneth lenpilot @ aol.com Cozy 522 Chapter 5 In a message dated 96-06-03 18:46:58 EDT, Roy Wrote: > > I've been reading lately the problems with laying up the landing gear >hard points and getting the correct layers and thicknesses. What if I >told you that there was some magical material out there that is exactly >.25" thick, comes in sheets and has over 35 layers of pressure formed BID? >Well the stuff is called G-10, and is available at your local plastics >shop; not store, but industrial plastic shop. > I called Nat on this one and he's not against using it, he did mention >he has never heard of it. We did testing on this stuff at school. The >material is about three times stronger then the 22 ply layup indicated in >the plans. The only drawback to using G-10 is it eats band saw blades! > I bought enough material for the hard points from a scrape bin, it was >around $10. It normally costs about $17 a square foot. If you can not >find it, let me know and I could mail a square foot for about $20. >Considering the time and material savings it may be worth it. > >ROY > >============================================================================= >Roy H. Grossinger- ME grossinr@rastro.colorado.edu >Cozy Mk IV #503; Chapter 4 ROY_GROSSINGER@Radon-hq.ccmail.compuserve.com > CU's Go - 4; Hull Layup "A man's destiny is his character" > >| ___ | http://bechtel.colorado.edu/~grossinr >|---------(>-<)---------| http://www.abwam.com/grossing > / ~~~ \ > o/ \o > > > Date: Sat, 6 Jul 1996 09:49:02 -0400 (EDT) From: Randy Crutfield Subject: Re: COZY: firewall layup chapter 4 Check Chapter 3 page 10 "Other Surfaces". To paraphrase, no special preparation is needed, make sure the surface is free of contaminants and rough it up with 36 grit. Worked for me, Randy From: RJMANC@cris.com Date: Sun, 7 Jul 1996 14:19:10 -0400 (EDT) Subject: COZY: Layups I am working on the first bulkhead. (the seatback) When cutting the und or bid and laying it at a 45 deg. It doesn't seem possible to cover the whole seatback with one piece .. I am I doing something wrong or should I piece 2 pieces together and do I overlap each piece and by how much overlap ??? Signed lots of questions ????? Robert P.S. I would like to thank mark for all his insight !!! And everyone who responded to my plea for help.. \______OO______/ | | O O #537 From: "Rob Cherney" Organization: Ellicott City, Maryland Date: Sun, 7 Jul 1996 16:00:20 -0400 Subject: Re: COZY: Layups > I am working on the first bulkhead. (the seatback) When cutting the und or > bid and laying it at a 45 deg. It doesn't seem possible to cover the whole > seatback with one piece .. I am I doing something wrong or should I piece 2 > pieces together and do I overlap each piece and by how much overlap ??? According to Burt Rutan's "Moldless Composite Homebuilt Sandwich Construction": "There is a difference in the way BID and UND are joined. When joining the edge or the end of BID and a BID ply, it is necessary to overlap it one inch onto the ply it is being joined to. When joining UND across the major fibers, it is lapped 1 inch per ply, but when joining UND along the major fibers it is butted next to the piece it is joining, not overlapped. Also, with UND it is not necessary to remove the selvage (edge of cloth) when making a wide layup such as a wing layup at 30 degrees. Lay the first piece on with the selvage at 30 degrees and butt the selvage of the next piece to it. With BID, the selvage is *always* removed." If you do not have this reference, you should get it. Additionally, there is a companion video. Both are carried by the major material suppliers. Rob- +--------------------------------------------------------+ |Robert Cherney Home Phone: (410)465-5598 | |Ellicott City, Maryland e-mail: cherney@clark.net | +--------------------------------------------------------+ From: Marc J. Zeitlin Subject: Re: COZY: Layups (fwd) Date: Mon, 8 Jul 96 9:02:21 EDT Rob Cherney wrote: >Robert Mancuso wrote: >> I am working on the first bulkhead. (the seatback) When cutting the und or >> bid and laying it at a 45 deg. It doesn't seem possible to cover the whole >> seatback with one piece .. I am I doing something wrong or should I piece 2 >> pieces together and do I overlap each piece and by how much overlap ??? > >According to Burt Rutan's "Moldless Composite Homebuilt Sandwich >Construction":................... This same explanation is in the COZY plans - check out chapter 3. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Mon, 8 Jul 1996 13:25:24 -0600 (MDT) From: Roy Grossinger Subject: Re: COZY: firewall layup chapter 4 > I'm ready to layup the firewall one layer of BID but i've never read > how to prepare a wood surface either in the plans or elsewhere. > I don't recall exactly where, but in the plans it does mention how to prep wood. You sand with course grit paper, and then glass. Peel strength is pretty good, don't micro! ============================================================================= Roy H. Grossinger- ME grossinr@rastro.colorado.edu Cozy Mk IV #503; Chapter 6 ROY_GROSSINGER@Radon-hq.ccmail.compuserve.com CU's Go - 4; Hull Layup "A man's destiny is his character" | | |---------(>-<)---------| http://www.abwam.com/grossing / ~~~ \ o/ \o Date: Fri, 12 Jul 1996 14:57:09 -0400 (EDT) From: ROBERT MANCUSO Subject: COZY: F-28 Bulkhead I am preparing to cut bulkhead F-28.. It states that you can cut this bulkhead at a 4.0" hight to make the nose more rounded. I was planning on purchasing the prebuilt nose from featherlight. I called featherlight and he didn't seem to understand my question and told me to order the part and the I could compare but it would take 30 days to get it.. Well I don't want this to hold me up.. Has anyone out there used a featherlight nose or any featherlight products ?? Is thier work good ?? And should F-28 be 3.3 or 4.0" ??? Robert Mancuso 1635 W. I Los Banos CA, 93635 Cozy # 537 Chapter 4 From: Marc J. Zeitlin Subject: COZY: F-28 Bulkhead (fwd) Date: Fri, 12 Jul 96 15:17:35 EDT Robert Mancuso writes: >.... Has anyone out there used a featherlight nose or any >featherlight products ?? Is thier work good ?? Their work is decent (from what I've seen - the nose strut, strut cover, nosewheel cover, etc.) but they are slow. >............. And should F-28 be 3.3 or 4.0" ??? I made mine 4" (per the new plans). It's purely an aesthetic thing, if you're building your own nose, like I did. Chris Scida on Long Island made his 6" high, and his nose is a lot more rounded (looks nice). If you're going to buy the nose, make it 4" - you can always sand it down later if you need to to make it match. It would take you all of 5 minutes to change. -- Marc J. Zeitlin Email: marcz@an.hp.com From: RJMANC@cris.com Date: Sun, 14 Jul 1996 18:11:06 -0400 (EDT) Subject: COZY: FIREWALL I am preparing to do the firewall .. My question is what are the alum. pieces used for engine mounts and where is a good place to get some. Thank you Robert Mancuso Los Banos Ca (209)826-6814 Chapter 4 00 \______O00O0______/ | | | O 0 O #537 Date: Sun, 14 Jul 1996 18:56:44 -0400 From: Paul Burkhardt Subject: Re: COZY: FIREWALL RJMANC@cris.com wrote: > > I am preparing to do the firewall .. My question is what are the alum. > pieces used for engine mounts and where is a good place to get some. > > Thank you > Robert Mancuso > Los Banos Ca > (209)826-6814 > Chapter 4 > 00 > \______O00O0______/ > | | | > O 0 O > #537 Bob, When you say "what are the aluminium pieces" do you mean the type of aluminium? , or what are they used for. I think they are 6061-t6 if I remember correctly, but maybe 2024-t3. The plans should state it. They are used as a hard point for the engine mount, you will later drill through them. I would recommend making the upper ones 2 inches long in the vertical dimension, as compared to the one inch square as recommeded in the plans. Paul burkhardt Date: Sun, 14 Jul 1996 17:44:33 -0700 From: Michael Antares Subject: COZY: FIREWALL To add to Paul's response, I got mine at Wicks as part of the chap 4 order (I didn't have to do anything special to get them) and I think they are 2024 T3 although it's hard to imagine it would make much difference if they were made of 6061 T6. 6077 Old Redwood Highway Penngrove CA 94951 707.664.1171 Cozy#413 Finished through chap 14 except chap 13. Currently on 16 and 24. Date: Wed, 17 Jul 96 10:00:04 -0800 From: Eric_Westland@msvl.wednet.edu (Eric Westland) Organization: Marysville School Dist. Subject: Re(2): COZY: F-28 Bulkhead > >> Has anyone out there used a featherlight nose or any featherlight >> > products ?? Is thier work good ?? >> Robert Mancuso 1635 W. I Los Banos > CA, 93635 Cozy # 537 Chapter 4 > >I just bought the landing gear and > nose cone. Both were fine and like Dick >said, expensive. The gear you > have to buy, but the nose cone is optional, but >worth every penny. > Placed on the F-0 bulkhead, it makes carving the foam from >it to F-22 > much easier. I highly recommend it. > >-eric > > Eric did you cut F-28 at 3.3 or 4 inches or does it matter...If I buy > the nose from Featherlight witch is the best way to go ... I built and installed F-28 when it was 3.3 and then changed it to 4.0 per newsletter. I also had to move it back a little when I installed the canard to clear the trailing edge. I ran into the same problem that a few others have, that is I have a 1/8" "dip" in the nose when viewed from the side. I never realized this until I put on my canard cover, so I had to do a little filling or rebuild the instrument and canard cover (not an option :-)). I probably would have been ok if I had left it at 3.3". As far as I undrestand it now, it really doesn't matter a big hoot either way as you can make adjustments as you go. Go for the nosecone no matter what - you won't regret it. Hope this helps. -eric -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Sent via ExpressNet/SMTP(tm), Internet Gateway of the Gods! ExpressNet/SMTP (c)1994-95 Delphic Software, Inc. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Date: Thu, 25 Jul 1996 00:46:39 -0400 From: Jim Hocut Subject: Re: COZY: Inst Panel At 12:00 AM 7/25/96 -0400, Robert Mancuso wrote: > > Ok I thought I was done with chapter 4. Then discovered the most >diificult thing ... Those darn stiffeners on the back of the inst panel... I >look at the pictures in the plan and I can not get the top of the glass to >stay that stright.. The lip of glass just seems all over the place... Any >suggestions on what I may be doing incorrectly ??? I was so discusted with >the way it looked I pulled it off !!! Help !!! > > Yeah, I remember that very well, had the exact same problem and wasted totally too much time striving for perfection. Then it dawned on me that those stiffeners will never see the light of day in the finished product anyway, and perfection is not called for here. What I finally wound up with is very acceptable. I did the 1 ply BID (the side that doesn't hang out) first, and after that had cured trimmed it flush with the stiffener (all these layups are at 45 degrees so the glass will conform to the bend easier). Also, before the glass is laid in place I ran a bead of flox along the base of the stiffener, and painted the stiffener with wet micro. As for the 2 ply layup that hangs over the edge, I made sure that just enough was hanging out past the stiffeners (about 3/8 " or so) as too much will make things more difficult. I wet out the glass ahead of time on a piece of wax paper (in this case I found it helpful to saturate the glass pretty well), and cut the wet out glass to size with my pizza cutter (wipe it off thoroughly with paper towel and it will survive with no adverse effects). Again, a bead of flox along the base of the stiffener and wet micro. You can pick up the glass "tape" with the wax paper still attached, lay it in place and get it perfectly aligned before pulling the wax paper backing away. Then, to get it to lay down flat at the "top" of the stiffener I laid an oversized piece of wax paper over the glass and put whatever I could find that was flat and heavy on top of that. There, long winded but I think I covered everything. Jim Hocut jhocut@mindspring.com Date: Thu, 25 Jul 96 10:00:03 -0800 From: Eric_Westland@msvl.wednet.edu (Eric Westland) Organization: Marysville School Dist. Subject: Re: COZY: Inst Panel > Ok I thought I was done with chapter 4. Then discovered the most > diificult thing ... Those darn stiffeners on the back of the inst > panel... I look at the pictures in the plan and I can not get the top of > the glass to stay that stright.. The lip of glass just seems all over > the place... Any suggestions on what I may be doing incorrectly ??? I > was so discusted with the way it looked I pulled it off !!! Help !!! It's been a while, but what I remember doing was simply cuting some square stock of wood or foam, wraping it in box sealing tape and laying up the stiffeners over them. Once cured, i just removed the wood. Turned out nice, but I will probably end up cutting most of them away if I go to the trouble of installing an aluminum instrument panel face. With the foam face, the instruments are somewhat recessed, but with the aluminum, you can bring them flush because it is thinner. I get nervous about the idea of cutting out some of this bulkhead, but I have seen it on quite a few planes. -eric -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Sent via ExpressNet/SMTP(tm), Internet Gateway of the Gods! ExpressNet/SMTP (c)1994-95 Delphic Software, Inc. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Date: Thu, 25 Jul 1996 17:58:00 -0400 From: DFinn7971@aol.com Subject: Re: COZY: Inst Panel In a message dated 96-07-25 00:08:46 EDT, RJMANC@cris.com writes: << Those darn stiffeners on the back of the inst panel... I look at the pictures in the plan and I can not get the top of the glass to stay that stright.. The lip of glass just seems all over the place... Any suggestions on what I may be doing incorrectly ??? I was so discusted with the way it looked I pulled it off !!! Help !!! >> Robert, The worst part about the stiffeners is that you do them while you are still fairly new to fiber glass work. Try cutting the 1/4" foam strips and glassing one side while they are flat on your work bench. Trim them to width and cut them to length after cure. Flox the various pieces onto the back of the instrument panel using 1 1/2" finish nails to hold them perpendicuar and in place till the flox sets up. Make sure the glassed side is in the what will become the trough. Drive the nails throught he edge of the strips into the back of the panel. After cure, remove the nails. Take a piece of foam the width of the stiffener and lay it along side the stiffener. Use a few dabs of 5-minute epoxy to hold it in place. Sand the foam flush with the top of the strips. and cover with duct tape (the handy mans fix-it-all). Round the edge of the foam for a good smooth bond, micro and lay up your glass. After it sets up trim the trough to the correct height and remove the foam. You'll have to do a bit of sanding to get all the foam out because it will stick where epoxy drips into spots where the duct tape doesn't cover. This could probably be done in fewer steps to eliminate waiting for the cure time between steps. I'd advise working with the glass through a few more chapters to get more of a feel for it before taking short cuts. As a final thought, if you find you'll need six 2" wide strips of glass that are 40" long, lay up one strip that is 13" or 14" by 42" on waxed paper. Once you wet everything out, cut the big piece into 2" strips and lay them on the foam. Stipple them down and peel off the waxed paper. This technique makes the glass easier to work with and saves a lot of wasted glass. Date: Tue, 20 Aug 96 08:18:30 est From: "Larry Schuler" Subject: COZY: Bulkhead trim Hi all, I will be moving on to chapter 6 (fuselage assembly) in the next week or so. While trimming a couple of bulkheads last night, I noticed that some of the inside edges, such as F22 leg cutouts, remain bare foam at this time. Those edges will be prone to delamination if left as is. Thought about routing them out a bit and filling with flox, but thought someone further along could tell me if this is taken care of in a later step. {Ok, I'm lazy and didn't want to re-read the entire set of instructions looking for it.} :-) Seems to me that pre-assembly treatment would be easier. Maybe I missed something??? Thanks, Larry Schuler MKIV-#500 Date: Wed, 21 Aug 1996 08:59:28 -0700 From: Michael Antares Subject: Re: COZY: Bulkhead trim At 08:18 AM 8/20/96 est, you wrote: > While trimming a couple of bulkheads last night, I noticed that some > of the inside edges, such as F22 leg cutouts, remain bare foam at this > time. Those edges will be prone to delamination if left as is. > > Thought about routing them out a bit and filling with flox, but > thought someone further along could tell me if this is taken care of > in a later step. {Ok, I'm lazy and didn't want to re-read the entire > set of instructions looking for it.} :-) > > Seems to me that pre-assembly treatment would be easier. Maybe I > missed something??? I'm sure most builders, like me, have not bothered to fill these surfaces. I have vague plans to do something about the instrument panel cutouts when I am doing the final finishing. The rest are either worked on later (the landing gear bulkheads) or are reasonably removed from being banged into (forward of the instrument panel). I think that filling them is perhaps a lot of effort for little benefit but on the other hand it certainly can't hurt! 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. Date: Wed, 21 Aug 1996 15:13:56 -0400 From: DFinn7971@aol.com Subject: Re: COZY: Bulkhead trim In a message dated 96-08-21 11:52:23 EDT, lschuler@cellular.uscc.com (Larry Schuler) writes about the bulkheads: << Thought about routing them out a bit and filling with flox, but thought someone further along could tell me if this is taken care of in a later step. {Ok, I'm lazy and didn't want to re-read the entire set of instructions looking for it.} :-) Seems to me that pre-assembly treatment would be easier. Maybe I missed something??? >> Nat's cutouts are still bare foam. A lot of fellows have routed them out with a Dremel and filled them with micro or flox (I would use micro as it would give a smoother finish). As to before or after assembly, I thinks its dealers choice. Some of them may get covered up later anyway. Dick Finn Cozy Mark IV #46 DFINN7971@AOL.COM Date: Mon, 02 Sep 1996 09:18:04 -0700 From: "Steven D. Sharp" Subject: Re: COZY: Chap 4, Glassing over Foam Keith Barr wrote: > > I've been watching this forum for some time as I've been preparing my shop. The > info is great (especially when there's more than one opinion) and I really > appreciate everyone's contribution. > > I've just glassed the front seatback (using L285 resin + L286 hardener from > Lange & Ritter in Germany) and noticed some tiny bubbles in the white slurry > layer on the back side of the seatback. I have a few more things to do before > using it in the fuselage, but I think it may be my first throw-away. The piece > looks okay otherwise and there isn't any air trapped in the glass itself. > > Does this mean I used a slurry too thick or didn't squeegy enough? Should the > overall appearance be white or a bit shadowy? The front side looks less white > (with no bubbles) but shows an uneven pattern in the white slurry under the > glass. It isn't patchy, just slightly shadowy and you can never quite see the > foam. I haven't had an opportunity to see other work so I'm not sure what the > appearance should be. > > Thanks in advance, > Keith Barr > #489 in the Netherlands Keith, From all initial thoughts, it sounds like you didn't squeegee enough. I have found it is best to move the slurry ofer the surface from several different directions making sure the little pores of the foam are filled. (I am assuming you are glassing PVC foam). Also, a stiff squeegee may also help. One point I might add - applying the slurry is a learned skill. In a couple of months it will be second nature. My $0.02 worth. Steve Sharp cozyiii@earthlink.net Prepetual 3 place builder (8 yrs and still spreading it - sometimes too thick). Date: Mon, 2 Sep 1996 20:24:51 -0400 From: SBLANKDDS@aol.com Subject: COZY: Chap 4, Glassing over Foam - air or micro??? Hi Keith, The slight color patterns that show from the micro layer may be from more or less micro thickness in some areas. Where the micro is thick and not squegeed out well, pure resin will later mix in to cause the swirl look. This may also occur if the micro is not mixed consistantly. Always mix the resin before adding micro to the cup. The consistancy should be like toothpaste for this job. The micro layer should be spread very thin just to fill the porosity in the foam to prevent pure epoxy from seeping in. You should not have a white micro layer covering the foam. If your glass is wetted out, and flat, well squeeged, then the peice is probably o.k. Later the map pocket will attach to the middle of the seat back and you will cut a hole in thre center. If you think the glass is not bonded to the foam, then you have scrap. On this large flat piece this would appear like a raised spot the is flexible, or if the fibers are wavy not straight. If you can, save all mixing cups, they work better the second time. I use a scrap can to dump excess resin, and throw old blades in to protect me from any sharp garbage. Steve Blank Port St. Lucie, Florida USA SBLANKDDS@AOL.COM Date: Mon, 30 Sep 1996 22:34:02 -0400 From: william l kleb Subject: COZY: chap 4/15: lower firewall/rudder pulley mounts have people found that the two sets of four MS24694-S54 screws in the lower firewall turn out to be long enough for attaching MKCS 71 rudder pulley bracket assembly? --- bill kleb (w.l.kleb@larc.nasa.gov) 72 bellanca 7gcbc 9? cz4 -> aerocanard by InfoAve.Net (PMDF V5.0-6 #4800) id <01IBEQJSLF1W8X8TLB@InfoAve.Net> for cozy_builders@hpwarhw.an.hp.com; Sun, 03 Nov 1996 12:23:08 -0500 (EST) Date: Sun, 03 Nov 1996 12:23:08 -0500 (EST) Date-Warning: Date header was inserted by InfoAve.Net From: Nick Ugolini Subject: COZY: Inst. Panel >> Vance had also indicated that a lot of people install the metal panels >> which screw into tabs on the inside of the fuselage. This would >> replace the upper portion of the existing instrument panel. > This may be a question Vance can best answer, BUT is there any structual or torsional issues to be concerned with when you cut out part of your bulkhead (the upper part of the insturment panel) and replace it with a non-structual piece of Al? Nick Ugolini unick@mail.charleston.net Varieze N89RS Cozy Mark IV #0264 Date: Mon, 16 Dec 1996 07:15:36 -0500 From: william l kleb Organization: NASA Langley Research Center Subject: COZY: chap 4: nose gear torque tube hole i was going to mount my rotisserie gizmo for chapter 7 to the nose gear torque tube hole in f22 which i had never drilled while doing chapter 4. i have decided to clamp my pivots to the bulkheads, but i am left wondering about the meaning of the correction listed in newsletter 38: http://www.ultranet.com/~marcz/cozy_mkIV/newsletters/mkIV_correct.html#news38 it says: 11. The hole for the nose gear torque tube should be off-center to the right and need only be =E6" I.D. besides the transcription error where "=E6" should be "3/4", where exactly is the center of the hole? is it 3/8" to the right of the centerline, or should i just relax and worry about it when the nose gear assembly goes in? --- bil kleb From: Marc J. Zeitlin Subject: COZY: chap 4: nose gear torque tube hole Date: Mon, 16 Dec 96 9:16:14 EST bil kleb writes; >besides the transcription error where "=E6" should be "3/4", I'll fix that :-). >.............. where >exactly is the center of the hole? is it 3/8" to the right of >the centerline, or should i just relax and worry about it when >the nose gear assembly goes in? The second one. I didn't make the holes (in either F22 or the Inst. Panel) until the installation of the torque tube in Chapter 13. The reason to have it off center is to miss the nosewheel cover. It's easier to do when everything's installed already; at least for me it was. -- Marc J. Zeitlin Email: marcz@an.hp.com