Thursday, August 11, 2011

Finishing the RV cowling

I'm kind of a neat freak and I don't care much for dust, so it's rather odd that I once considered building a GlaStar, a plane that is all composite with metal wings. It would have required lots of chemicals and lots of sanding. And lots of dust.

After I sent my deposit in on a GlaStar kit, the company went belly up, so I bought an RV airplane kit instead.

But there's plenty of fiberglass work on these things, too. I'm knee deep in it. I still have plenty of fairings to construct, but first I need to finish the cowling, which I actually started almost two years ago.

All the fitting is done now, of course, and the cowling is being prepped for an eventual paint job. With fiberglass, there are thousands of pinholes which will show up as soon as you finish that $5,000 job. You have to get rid of them first.

My technique worked well on the top cowling, so there's no reason to change the bottom cowling portion. The first step was to thin some epoxy with acetone and brush it on, after a good sanding with #80 grit sandpaper.

Sure, it looks all shiny and stuff, but don't let it fool you; it's full of pinholes. Some of them, hopefully, will be partially filled.

The next day -- yesterday, actually -- I sanded it all off with more #80 grit. Then I mixed up the two-part SuperFil, spread it on and squeegeed it off, except for the small part that filled in the pinholes.

Then this evening, I sanded that all off -- yep, #80 grit -- and opened up an almost-empty can of Super Prime, which is a VERY weighted primer filler that you roll on. It'll fill in, hopefully, most of the pinholes that are left.

I'll sand this all off, too, and then add three more coats and sand it with #180 grit and it should be ready, then, for a nice epoxy primer. Unfortunately, I probably don't have enough left, and it's $60 a quart. I got in the wrong business.

None of this will be done until September, apparently. We're heading out on a vacation back to New England.

Oh, I also installed the fuel overflow tube today. That should be the last item to be installed on the engine. We're ready to go through the process of starting the engine for the first time.

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