Dave’s RV-7A Building Log

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.

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.

ProSeal session #2. Can’t think of a better way to spend my birthday (not). I managed to rivet in two ribs, the cover for the tooling hole on the outboard rib, and spread some ProSeal on the connector for the capacitive plate. Julie helped me with the second rib, and things went much, much faster. I’m going to beg, plead, offer back rubs–whatever it takes to get help on the other ribs. It’s just so much faster and easier.

There was a nice breeze blowing through the garage today, so I mainly wore the respirator during clean up with the MEK. It was nice not wearing that thing the whole time.

I got plenty of ProSeal on everything and still had 1/2 tube left over. There was a couple of spots in the tube that didn’t seem mixed very well. I threw them out. I’ll do more mixing next time. The directions say 50 strokes with the mixing ram. I’m counting each direction as one, but maybe that’s not enough.

Overall, the session went great.

I was going to assemble the access cover reinforcement ring and nut plates with ProSeal, but the instructions say it isn’t necessary. Other builders have skipped it as well. I decided that less ProSeal is a good thing. I riveted on the ring and nut plates.

First session with the ProSeal. I got everthing ready, rivet gun, back riveting set and plate, cut up shop paper towels and put them in a Pyrex bowl for pouring MEK over them. Soaked the rivets and cleaned the parts. I’m using the ProSeal tubes, so the mixing and application was very easy. I mixed it up a little early. I should have taped in all of the rivets first. I got into a pretty good rythm of frosting up a stiffener, pushing it down, back riveting, and then covering the shop heads with ProSeal. I have a fairly small back riveting plate. I ended up going off the end of it twice, but then didn’t do it again the whole rest of the session. Hopefully I’ve learned that lesson now. After riveting on the first stiffener, I noticed little dots on the skin. Doh! Forgot to wrap a rag around the rivet gun to keep it from spitting oil on the skin. Cleaned up with MEK and continued on.

I next attempted to back rivet the fuel flange. That did not go as well. The flange is curved, and I didn’t have it pushed down on the back riveting plate hard enough at the very front and back. The rivet heads were proud of the skin. Drilled them out (which is not fun with ProSeal everywhere) and tried them again pushing down on the flange this time. Worked much better. One rivet that I drilled out was stuck in the fuel vent line clip, so luckily I had a spare clip to use instead. Pulled off all of the tape and cleaned up with MEK.

I had planned to do the drain and coat some of the fuel sender parts, but 3 hours of messing around was enough for one day and I was getting hungry for dinner.

Dealing with the ProSeal and MEK was not too bad. But that’s what they all say after the initial session. I ended up using almost 1/2 of a tube. It was starting to set up pretty good after 1.5 hours, so I doubt I could have used the whole thing anyway.

Using a Scotchbrite pad, I scuffed up all of the surfaces of the left fuel tank that will get ProSeal. The solvents will remove the pen marks, so I marked the parts with the electric pencil. Test fit everything and laid out the parts. Now I’m just debating about whether to dive in, or work on the leading edge.

Did a bunch of miscellaneous stuff, getting the left fuel tanks ready for assembly. Dimpled all of the fuel tank skin holes with the C-frame. I decided to try dimpling on the floor. Hammering on the C-frame definitely has a more solid feel, but it’s very uncomfortable being on the floor. You’ll also notice that I taped over the holes that are counersunk already. I didn’t trust myself not to accidentally dimple them.

Smoothed the edge of the tank skin. Deburred and smoothed the tank baffle. Fabricated a little cover for the tooling hole in the outboard rib.

Soldered and crimped on connectors for the capacitive fuel sender.

Cleaned up the shop a bit and read through the assembly instructions again. There are an incredible number of parts that go into the fuel tanks. Here are most of the parts, excluding the tank skin and the vent line.

Deburred all of the holes for the cover plate and countersunk the holes in the reinforcement ring. Dimpled the screw holes in the tank skin.

Drilled all of the holes for the fuel tank cover plate, including the nut plate rivets. Started deburring the holes.

I finally got up the nerve to cut the big hole in the inboard rib for the left tank. For some reason, that step had me nervous. I used the fly cutter. The hole came out great. Since I had everything set up, I decided to cut the hole for the right tank as well.

I also located and cut holes in the ribs for the vent line and the connector for the capacitive fuel sender. The final thing I did for the night was to cut holes in the blank access covers for the standard fuel pickup. I used the other cover with the extra hole for the float sender as a template. I decided to move the anti-rotation bracket just a few millimeters closer to the angle fitting, so that it wouldn’t interfere with the pick-up attachment.

I started to drill the holes for the cover plate screws, but decided to wait until tomorrow when my order from Cleaveland arrives with the black clecos. That should make the job a bit easier.