Dave’s RV-7A Building Log

Clecoed together the VS spars and ribs. Drilled out the hinge brackets and the rear spar stiffener. I can already tell this part is going to be a breeze compared to the HS.

We’re riveting! With Julie’s helped we did all of the field (i.e. can’t reach with a squeezer) rivets on the bottom side of the left HS. It took a fair amount of monkeying with air pressure and the regulator at the gun in order to get the right combo. We used 80# at the compressor outlet and about 1/2 closed on the gun regulator. We practiced a bit on a piece of scrap until Julie felt she had the timing down pretty good. She generally would shoot for 3 seconds. And then I’d signal whether it needed another 1/2 second by visually looking at it. And then I’d follow up with the gauge after a whole line was done.

The rivets turned out better than I expected. It wasn’t nearly as hard as I thought it was going to be. I did have to drill out one rivet. I let the bucking bar slip off the shop head. Julie was so understanding, “It’s nobody’s fault.”

I had a tough time getting even the small bucking bar into the small space inside the HS. I ended up polishing a spot on the side of the bucking bar–easily done with the grinder followed by Scotch-brite.

We also shot the two 470AD4 rivets that hold the 702 and 706 together, per the instructions. That took more adjustments with the rivet gun, since they’re a bigger rivet. It was also hard for Julie to keep the gun on the round head (vs. the flat heads with the 426AD3 rivets on the skin). She did a great job, though.

Big day. It’s starting to look like a real airplane part!!

Started on the vertical stabilizer. Clecoed together the rear spar and stiffener. Prepared the ribs. Read ahead in the instructions.

Touched up the primer on a few of the HS ribs. In the last priming session, I didn’t hit the ends very well on a few of the ribs. I also primed the inside of the skins. I was planning on using the self-etch primer and just doing the rivet lines. However, since I had the HVLP sprayer set up, it wasn’t much extra trouble to prep and spray them with the water-based one-part epoxy primer. The session went much better than with the touch-up sprayer. I couldn’t tell how much paint I needed to put on, and got it a little thick in a few places–a few runs.

Deburred the edges of the other HS skin. Flattened out the hole I accidentally punched in the skin when I was dimpling with the C-frame a few days ago. After flattening it, I dimpled the right hole.

I also set up some scrap pieces for practicing riveting with the rivet gun. The rivet gun isn’t working real consistently yet. Seems like a lot of oil is spurting out of it. Maybe it just needs to be run for a while.

Deburred the edges on one of the HS skins. That went pretty fast with the Scotch-brite wheel. I touched up the corners a little bit with a fine file.

Called Van’s builder’s assistance line this morning. They said the extra hole is not a problem. Just dimple the correct hole and put in a rivet. When I go to paint the plane, I can fill in the hole with putty.

Another screw up. I was dimpling along with the C-frame dimpler trying to wrestle with the HS skin, and I didn’t notice that the skin popped off of the pin on the dimple die. Made a nice hole right next to the real hole. Kind of a figure 8. I’ll call Van’s and find out what the solution is. I don’t want to start over with that skin. It’s almost ready to go. Unfortunately, the mistake is on the top of the HS.

It was a productive night however. I finished dimpling both HS skins. After the screw-up, I got some help from Julie to do the holes that are way inside the crease of the skin. I also looked over the spars and drilled out a few rivets that squeezed way over to the side. I re-squeezed them and they look much better now.

I just need to smooth the edges of both HS skins, prime the rivet lines, and I’m ready for some riveting!!

Started using the C-frame to dimple one of the HS skins. I didn’t get too far, as I spent quite a bit of time clearing space on the workbench in order to use the C-frame. Feels good to be making progress again. Even if the garage is 30°F.

Time to return to building. I passed the FAA knowledge test with a score of 98%. Not bad. But now I’m worried about the folks up in the air that passed with 29% (i.e. 71% pass rate) of the questions wrong. A few of the questions on the test seemed silly, but most of it should be required knowledge.

Picked up some Sherwin-Williams 988 G.B.P. Self Etching Primer in a rattle can for about $7. Jeff suggested hitting rivet lines inside the skins with some Napa 7220. After trying to hunt that down for a few days, I found out that SW 988 is the same thing. It’s only available at the stores that carry automotive finishes, but there’s one of those just a few blocks from where I work.

Also did some final clean up in the garage. One car fits in the garage (for now). That’s as good as it’s probably going to get.

In case you care about my beautiful garage, here’s the before and after pictures: