« Archives in July, 2010

More Canopy fairing

5 hours.
Another combination entry, since you all don’t need a play by play on the iterations of goop happening with this canopy fairing, but beginning 7/2 and ending today I’ve done the final shape of the radius, put down 4 layups of 8-oz crowfoot glass, and a fill/smoothing layer of black-tinted micro. Shelley’s real good with cloth, so she helped do the layups, which was a bonus since it took 2 of us to get a canopy-wide strip of wet glass on there. I used the plastic-sheet/squeegee method to prepreg the cloth and we laid them up wet. That stuff stretches like crazy when it’s wet, because the weight of the resin pulls at it, as well as having part of it stuck while you’re positioning something else.. But the magic sponge did its job.. I was able to get everything to lay flat and the edge came up to the electrical tape boundaries I’d made.

This is after the peel-ply came off and I hit it with some 60-grit. I”m not going to show you every iteration of sanding, because I use my iPhone for music in the shop and I don’t want to get it full of dust, but suffice it to say that there are many iterations of this. Right now, there’s a bunch of black micro hopefully slathered into all the low spots, and tomorrow morning I get to sand it all smooth. I hope this works.

Canopy Fairing.

12 hours.
Not all at once, though. Last weekend, I got the canopy all ready for fiberglassing and put a bead of black-tinted flox mixture under the seam between the plexi and the canopy skin. I got pretty lucky shaping it, but there were a lot of bad holes and things that needed to be filled.

This shot is before the first attempt at filleting that radius. I got the shape I needed by wrapping some 80-grit around a piece of 1″ PVC pipe and carving it all back to bare plexi where it meets the fillet goo, leaving the ramp down to the canopy skins. The sides are farked. I had to cut the tabs off of the canopy skin where they meet the side skirts because I could never get them to lay flat against the plexi. Meh.

And here’s the wet fillet under peel-ply. This didn’t work that well. I managed to put a few significant ripples in the filler in the attempt to apply the dacron, causing some low spots.
After at biztrip up to San Francisco, and a fun-filled week of work adventures I went back to it. I’m starting to lose my fear of the epoxy goo. With the right tools, protective gear, and preparation, using epoxy doesn’t have to be that big a mess, even with the black pigment in it. This evening, I got a second fillet layer on there, filling in some low spots and widening the radius of the fillet a bit. This time I took a hint from jeffs-rv7a.com and cut the peel ply into small pieces. Actually, Shelley did the small pieces, I just put them on there and dabbed them lightly with some wet clean epoxy and a small sponge. I rolled a 4″ piece of pvc along the radius to give it a shape, but the sides are going to stay fairly flat. This is going to be weird, but I think it’ll work.

Here’s after tonight’s application of black goo. The black pigment gets mixed in to the flox/epoxy mixture because we want the fillet to blend into the black of the glareshield. The little strips of peel-ply work a lot better than a couple of long strips.

Still going to need tons of work, but I think after the next round of shaping, it’ll be time for the actual fiberglass.