Cozy MKIV - Chapter 7

Building the Fuselage Exterior

Start Date: March 25, 1995

I started out by cutting out the urethane foam for the NACA scoop area, as well as the plywood braces and foam for the LG Bulkhead/Firewall area. I micro'd the foam in place, floxed the plywood braces in place, put 2 BID on the firewall/RLG bulkhead braces, and then sanded the foam to shape. I then contoured the bottom corners of the fuselage, being careful not to cut into the bottom longeron more than indicated (no more than 1/4" showing). I also faired the fuselage sides back in the area under the spar cutout to come flush with the firewall.
raw outside

I wasn't comfortable (for no particular reason) with the aluminum inserts for the LG cover screws being only 1/4" deep, so I made them 1/2" x 1/2" x 1/4", and floxed them in place after routing out the holes for them with a dremel tool. I glassed 2 BID on the two scoop areas (in front of and behind the LG opening) and had a hell of a time getting the glass to lay down in the 1" x 1/8" "joggle" recess for the LG cover (as Marty Kansky said I would). I used peel ply, wooden strips, tongue depressors, and weights in a Rube Goldberg setup to hold everything in place overnight.
NACA scoop area

I trimmed the scoop, floxed the scoop corners, routed a cable channel for a NAV antenna in the fuselage bottom, and soldered and glued up a NAV antenna per RST standards. I hot melt glued this in place in the channel, stuck the copper tape to the foam, and pushed the cable through a hole in the fuselage just in front of the Instrument Panel. Here's the antenna (after glassing):

I rough cut a piece of wood for the step mount, and cut the foam away from the fuselage for it to mount in. I hot melt glued the brake back in place, and used duct tape to build up the area around it. I then cut the glass for the bottom layup, and then microed the antenna cable in the trough. I floxed the step mount in place, and shaped it to match the fuselage after cure.

Then, I microed the whole fuselage bottom, carefully lined up the UNI glass, and epoxied the 2 layers of UNI in place. I added 3 layers of UNI around the Landing Gear and Motor Mount attach points, and then peel ply'ed the edges. I checked the side-side and front-back level, and then left it alone for a day. Here's the bottom layup:

glassed bottom

I sanded and trimmed the bottom layup around the edges, and then turned the fuselage over and used a Stanley Surform plane to carve the top of the fuselage sides to shape (using the templates as a guide). Here's what that looks like:

sideways and mounted it on the "A-frames" with quick-clamps.

sides ready for

Again, I microed the whole fuselage right side, carefully lined up the UNI glass, and epoxied the 3 layers of UNI in place, one at a time. I added 3 layers of UNI along the upper longeron, and 3 layers of UNI around the Landing Gear and Motor Mount attach points. I added the 2 layers of BID around the rear bottom corner, and then peel ply'ed the whole thing. I checked the vertical level, and then left it alone to cure. Here's what the right side layup looks like:

glassed sides

After trimming and sanding the right side layup, I flipped the fuselage and repeated the whole deal for the left side. I've got a finished, lightweight, fuselage tub that I can sit in (with the fuselage on foam blocks) and make "VROOM" noises with my son. Here's my wife and son doing exactly that:

family in tub

End Date: April 23, 1995


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Copyright 1995, 1996, All Rights Reserved, Marc J. Zeitlin