Dave’s RV-7A Building Log

The left fuel tank is leak free!!! The water level dropped the first day, but the temperature was lower. I pumped up the tank a bit more, marked it again, and watched it for another day. It held rock steady. Loctite 290 is a great solution for a leaky rivet.

I spent some time cutting and sanding down the extra ProSeal I had put on the baffle-to-skin rivets. This build-up was interfering with the inboard part of the wing spar reinforcements and preventing the tank skin from laying flat.

I removed the left bottom skin and then clecoed just the flap hinge to the flap brace. I countersunk the flap brace using the hinge as extra support for the countersink cutter. Worked great.

I then deburred the holes I had just drilled for the flap brace and dimpled that aft-most line of holes on the skin. I also did a little trimming on the flap hinge. Once I verify that the tank is leak-free, the left wing should be ready for bottom skin riveting.

I also made the bushing for the right aileron mount and put all the necessary washers in. I followed the call-outs on the plans for the washers, and it was a pretty tight fit. I’m not sure whether to follow the call outs, or modify it so that it’s not a tight fit. I know I don’t want to modify it too much, otherwise the aileron nose might hit on the brackets on one side or the other.

I was going to move onto something else, but decided to get out the Shop-Vac and do some clean up instead.

Finishing up these wings seems to be taking forever. Looking at Dan C’s page, he spent about a week doing what I’ve been working on for a month. He must have been really hauling at the end of his wings.

I was debating about drilling the flap hinge to the left wing before or after riveting the bottom skins and decided it didn’t matter. I might as well do it now. First, I fabricated the spacer bushing for the aileron bracket and installed the various washers. I made a homemade device to hold the washers in that tight space while installing the bolts. It worked adequately. I then lined up the tooling holes in the wing end ribs and aileron to put the aileron in the neutral position.

With the aileron properly positioned, I clamped the flap in place with a side cleco clamp at each end. I didn’t think these would hold very well, but they did. One problem is that I had to remove the clecos holding the flap brace to the bottom skin. In order to keep them at least close to lined up, I placed a couple of rivets at each end. I then used a laser line along the trailing edge to get the flap lined up perfectly with the aileron. I drilled out the hinge, putting a cleco in every hole, and using a punch to make sure the flap brace and bottom skin were lined up. At first, I removed the flap. But then I figured out that the hinge was sagging and the flap needed to be there to keep it lined up right.

It’s nice to have that finished. Now it’s just a small matter of riveting the bottom skins and a few other minor details for the left wing.

Set up the manometer on the left fuel tank to see if the leaky rivet is still leaking. The level went down a bit during the night, but that’s probably because it’s cooling off. I sprayed some soapy water on the problem rivet, and there were no bubbles. We’ll see how it’s doing tomorrow

Primed the outside of the large push rods with a rattle can.

I did the rest of the blind and squeezer riveting on the left flap. I probably could have done the riveting along the top of the spar solo, but Julie offered to help. We cranked that out almost without any problems. The inboard-most rivet was impossible to buck, so I used a blind rivet there. The left flap is done!! Now i just have to drill the hinge to the wing.

Julie helped me finish the interior riveting on the left flap. For some reason, we had a tough time tonight. We were just not in the groove. I slipped off the shop head a couple of times. Julie slipped the gun off the flush head a few times. I was switching between using the yoke for the tight spots and the bucking bar for the easy spots. The yoke takes a lot more hits to set the rivet. When I’d switch to the bucking bar, we overset a few of them. I actually had to use a few oops rivets for the first time. Those things work great.

We eventually got all of the interior rivets set including blind rivets in the corners were it’s impossible to buck. I then put on the rear spar and blind riveted it to the ribs. I was able to get two solid rivets in the spar to outboard rib. The plans say to use blind rivets there, but solid rivets were no problem. I did have to use a blind rivet under the curl of the top skin. I also squeezed the rivets holding the two reinforcement pieces together.

I had intentionally stored the hinge on top of the spar, so I wouldn’t forget it. It’s a good thing I did that. I removed one eyelet from the middle of the hinge with the band saw and Scotchbrite wheel.

I could keep going, but I’ll quit while things are going well. It’ll take just another hour or so to finish this flap. These things are definitely not easy to put together.

Set up the left tank to finally fix the one minor leak in the rivet just forward of the fuel filler. Van’s suggested to use some wicking Locktite 290 with a slight vacuum in the tank. I hooked up a tube to the fuel pickup and sucked the air out. I applied a little Locktite to the bad rivet and let it sit. You can just make out a tiny bit of green in the (fuzzy) picture. I’m not sure how long it takes for the Locktite to dry, but I’ll test it in a few days.

Finished dimpling the bottom skins for the right wing with the C-frame. I believe I am done with the monotonous wing prep. Woo hoo!! I also clecoed the bottom skins on the right wing and drilled out the flap brace. The wing looks pretty cool with the aileron and bottom skins on there.

Finished deburring and started dimpling the right outboard bottom skin.