Matt's RV-7 Project

I haven't worked on the airplane in a little while, but I have been keeping busy with other things. For example, we finally broke down and bought a new TV to replace the third-hand 27-incher I bought from a guy at work for fifty bucks many years ago. However, I'm too cheap to pay hundreds of dollars for a simple stand to set the new display on, so I decided to build my own.

Woodworking is not my forte, but I managed to put together a pretty decent looking cabinet out of laminated pine planks and a sheet of birch ply for the back. It took me about three evenings to get all the pieces cut, fitted, and sanded, and then Mary and I spent half a Saturday putting it all together. The top is attached with Miller dowels for a smooth finish.

I've built plenty of workbenches, storage shelves, and sawhorses in my time, but never anything that actually had to look good, so the wood-finishing process was new to me. I was worried that the low-quality pine I used wouldn't take the stain evenly, but after a coat of pre-stain sealer and a coat of oil-based stain, it looked pretty darn good:

I let it dry overnight, and then applied the first coat of clear varnish. Almost immediately I could tell something was wrong… the varnish started moving the stain around! Arrgh. The varnish topcoat went on okay, but it seemed to somehow soften the stain and cause blotchiness. Either the stain wasn't all the way cured, or perhaps the wood really is of such bad quality that the stain didn't really soak in. Oh well – I'll just tell people it's a "distressed" finish. I was pretty distressed when I saw it.

I sanded the first coat of varnish with 400 grit, then put two more coats on over the next couple days. I sanded the final coat with 800 grit crocus cloth for a nice smooth finish. So here's the final product – my old stereo stuff will go underneath, and the cables will pass through the holes in the back:

Overall it turned out pretty good, except I'm pretty disgusted with the finish. The total cost was under a hundred bucks, not including the value of my time. If I had it to do over again, I'd probably make it out of something better than pine – oak, maple, maybe something else? – and be more careful about the staining process. I'll probably also use a semi-gloss topcoat next time, instead of satin.

Well, that's done. We now return to our regularly scheduled airplane building.

Fuel and oil hoses in the engine compartment are protected by firesleeve, which is like a piece of fire-resistant silicone tubing filled with asbestos fluff – well, probably not actual asbestos, but close enough. Because the throttle and mixture control cables come so close to the exhaust pipes, it's a good idea to firesleeve them too (firesleeve is both a noun and a verb!).

To keep the inner lining from soaking up oil and moisture, which would ruin its fire-resistant properties, it's necessary to dip the cut ends of the firesleeve in some kind of waterproof substance. There is a genuine aviation-grade "end dip" that's used by certified shops, but it sells for the outrageous price of $117.95 a quart! No way am I paying that much. So, I figured there were basically two readily available substances that could be used as a homebrew firesleeve end dip: Plasti-Dip and plain old RTV

In the interest of science, I procured a container of each and used the products within to treat the ends of a pair of two-inch lengths of firesleeve. After letting them cure overnight, I evaluated the results. The Plasti-Dip (on the left in the photo below) was more brittle than I had expected, and developed cracks when the firesleeve was flexed gently. The RTV remained slightly rubbery, as it is wont to do, and the end of its test piece remained well sealed after the flex test. Advantage: RTV.

Then I got out the matches and started burning stuff. When exposed to direct flame, the RTV became charred and began to emit a small amount of smoke, but would not ignite. This seemed like appropriate behavior for the end of a piece of firesleeve.

The Plasti-Dip sample, on the other hand, caught fire quickly and burned like a candle until I snuffed it out:

Conclusion: I will treat the ends of my firesleeve with RTV, and leave the Plasti-Dip for the occasional screwdriver handle.

My brother and me working on some little detail:

Showing off the panel to my dad:

Mary, me, and my brother: