05/06/2018 Completed Practice Kit

After roughly 14 hours of experimenting in the past week, I completed the practice kit by myself today.

I have actually completed one in the Synergy Air class back in January, but at that time I felt rushed by the class schedule as I didn’t have time to read through the instruction and I didn’t have enough chances to make bad mistakes (other than mistakes caused by pure bad technique) because instructor was always telling me exactly what to do at every step.

Experimenting with primer

I decided to try out the Primer on a few small pieces in the practice kit to have a general idea about the primer and its characteristic. Some people go crazy with the primer to protect the airplane at all cost, but I think it’s kind of useless if the airplane lives 60 years but the builder die early due to the carcinogens in the primer. It looks like the better the primer in terms of corrosion proof and quickness to cured, the more deadly it is. I decided to go with the simple auto primer to provide some minimum corrosion, and I’m planning to use Rust-Oleum Self Etching rattle can primer because it’s easy to apply.

Tight area dimpling/riveting

This is the most time consuming part. I don’t have a drill bit that’s powerful enough to drill a hole in a piece of steel as described by the practice kit manual to make a special dimpling tool. I drilled for 10 minutes on a piece of steel with not much progress. So I turned to buying more tools.

For dimpling, for some reason I just can’t remember what I did at Synergy Air to get them dimpled, so I have to find out how to do it myself. First I bought the pop rivet style dimple dies from Aircraft Tool Supply, but the space is too tight that I cannot even put a nail through the last hole on the rib near the trailing edge. Then I found two pieces of tools mentioned on Vans Airforce forums, a Tight Fit Dimpling Fixture(I bought a .401 Rivet Set w/ 3/16″ hole to go with this fixture) and a 3/32 VISE GRIP DIMPLER on Cleveland Aircraft Tools. These two work as advertised and I was able to continue my project after waiting two days for shipping.

For riveting, I do remember the indirect riveting technique I learned from Synergy Air. In fact, they have a video on EAA website, too. But the only problem is that I don’t seem to have the kind of tapered bucking bar that I could insert into the tight area. I tried using a piece of thin steel and I tried using the other end of the Tight Fit Dimpling Fixture, but none of them yield satisfying result. So I went searching Van’s Airforce again, and found a recommendation to try buy a chisel at Home Depot. I found one that looks strong yet thin enough for $8 at Home Depot. It’s still not as easy as other riveting technique, but at least I was able to back rivet those last few rivets with that chisel.

Rolling

I found out I had under rolled the skins quite a bit when I clecoed them together. I knew I under formed the skins because I compared it with the kit I made with Synergy Air. Curious about the consequence of not fully forming the skins, I decided to go ahead and put in the blind rivets. Well, of course Van’s instruction is right, it definitely looks ugly and there’s a big gap and I’m sure the rivets are under stress. This is something I need to definitely pay attention to during the actual build.