Month: April 2020

Last night and again today I spent a few hours dimpling the side skins. Doing in one session would have been faster, but each time I started I got interrupted. In any case, I rigged up some extensions by placing some sheets of particle board cover with carpet on boxes, and strapping them down with tie downs. I was able to adjust them a little to ensure I had the right support. The holes on the curved edges were the most difficult, but I found a way to make it all work.

Today I primed the side skins. It was quite straightforward, and aside from looking a bit patchy, I’m happy with how things came out.

Tonight I finished countersinking the longerons. Another round of very consistent holes. One more thing I found useful was a countersink drilling table another builder had made by measuring the thickness of the skin to be mated, he came up with a range of hole sizes. This is easier to measure than the depth of a rivet in the countersunk hole.

Today I countersunk one of the longerones, which took an hour or so. First I set up my single flute countersink, and dialed it in on the drill press. With that done, I hooked up my air drill and countersunk one of parts.

I was really happy with how it worked out. The single flute is superior, and requires a lot less pressure to cut. The consistency of my holes was much better than with the 3-flute sink, and it felt easier to use for some reason.

After a lot of drilling, it was midnight and the compressor had been running almost continuously. I decided to tackle the other one tomorrow

Over the last two nights I deburred the side skins for the aft fuselage. I spent probably two hours total time, including a few minutes to remove the vinyl on the exterior side. I used an oversized drill bit to debur the holes, which I found more effective than using a countersink bit.