Dave’s RV-7A Building Log

No progress last night on the plane, but I completed my night cross-country toward my PPL. Just one more hour of requirements (simulated instruments).

I got into a groove countersinking all of the #40 holes on the main spar. I was using a thick piece of scrap aluminum with a #40 dimple to test the depth. I finally figured out that wasn’t working very well. Using a thinner, smaller piece worked better. It wasn’t so rough on the back side of the dimple.

I believe I am now ready to rivet the leading edge on for good. I remember reading that somebody put a slight inward curve on the edge of the leading edge to keep it from curling up. I’m not sure how to do that now that the leading edge is already dimpled. There’s no room to get the roller on there. Maybe I’m just being dense.

Countersunk some of the holes in the main spar for attaching the skins. There are a whole bunch left to go. Took most of half an hour just to set up the proper depth on the countersink. Don’t want to mess up the main spar now.

I thought I was ready to ProSeal in the end ribs on the left tank, but I’m not. I figured out that I forgot to put the nut on for the coax connector. I had to cut out that wire and use parts for the other tank, re-crimp, re-solder. And then tighten down the connectors on the inboard sender plate. And then mask off areas that I don’t want ProSeal on (rear baffle, fuel vent and pick-up connector threads). And then I started looking carefully at the rivet heads that I swirled ProSeal on in previous sessions. There are several of those that I want to hit again. And then I had to figure out the rivet sizes to use in various places. But now I am fully ready. Too late to start tonight, though.

Decided to try out using a Jacobs chuck in the air drill. I picked it up at Home Depot. I’m tired of using the chuck key to switch back and forth between bits. The new chuck is significantly larger than the old one. We’ll see if it gets in the way.

[edit 1/13/2005: This chuck has worked out great. Run down to Home Depot and pick one up. It’s much easier to change drill bits. There have only been a few places where its larger size has been a problem, and then I just use the 12″ bits.]

Worked on the capacitive senders for the left fuel tank, and installed the vent line. The vent line takes quite a bit of messing around getting the length right and bending it a bit at both ends. Didn’t help that I flared the end before putting on the nut.

The senders also take a lot of messing around. The next sealing session is going to be tricky. I need to do things in just the right order: coat the connectors with sealant, put sealant on the BNC connector and vent connector, seal and rivet the end ribs, and then put in the tank attach angle.

Here are pics of the outboard sender, the end of the vent line, the inboard senders (just sitting loose for now), and the inboard end rib just placed to give some slack in the wire for putting on the connector in the next bay over.

I canceled a bike ride with my buddy Steve in order to do more house projects, but Julie was content just to work in the yard today during the extremely nice weather. So I worked on the plane, of course.

Dimpled the top left outboard wing skin.

It’s now ready to go. Just need to countersink the wing spar. I’ve been putting this off as countersinking is one of my least favorite operations. I just can’t seem to get repeatable results. Maybe my countersink cage is bad.

During the last priming session, I made up a little test strip of primed aluminum. I prepped and primed it just like any other part. I nailed it to an exposed place in the yard. We’ll see how it holds up over the years.

Deburred the rest of the holes on the top outboard left wing skin.

Spent most of the day installing a new garage door opener. Got tired of the old one opening spontaneously.

Riveted in the remaining 3 interior ribs in the left fuel tank with lots of help from Julie. Also riveted in the drain. I had planned to do a few more things, but that took long enough. Things got real messy toward the end, but MEK cleans everything right up. Used about 2/3 of the tube this time. It started getting pretty thick after about 2 hours. I had to turn up the pressure on the Semco gun to get it to flow out at a reasonable rate.

I’ve noticed a few folks puts lots of sealant around the drain. I figure I want every potential drop of water to make it to the low point, so I made sure there were clear channels between the rivet heads.

Progress has sure slowed with the nice, warm evenings we’ve been having. It’s more important to spend time with the family anyway.

I smoothed the edges of the left outboard top skin and deburred the inside of most of the holes.

In case I didn’t mention this before, I’m removing all of the blue plastic from now on. It takes way too much time to remove just the strips. I’m very careful with the skins, and they get no more scratched up than when I leave the plastic on.

Fuselage kit is scheduled to arrive the week of June 21. Woohoo! Even though I have a ton of work left to do on the wings, I can hardly wait until it gets here.