I’ve cleaned up the remaining work on the rail installation. Everything is deburred, and ready for the final installation of the new rails, save the nut plates between the F-804c bulkheads. Show Planes states that this should be a single leg nut plate that uses the existing rivet hole as the center hole and that the #6 screw hole should be approximately 1/4 inches from the longeron edge. The result would look something like the picture below (with the nut plate on the other side). However, this looks rather different from the picture, which is hard to make out. I plan to email Show Planes to make sure.
I might be jumping ahead in the build a little bit, but I’m trying to get as many structural parts complete and ready for priming as I can for maximum efficiency. With that in mind I tackled the forward skin yesterday. This is a nerve racking cut, and it took me awhile of playing before I was happy with my lines. Here is the skin installed. You can see I’ve already made the cutout for the baggage compartment. You can see where the normal cutout for the stock kit would be made.
The lower cut is made parallel to the longeron. The longeron slopes down at this point, so you can make the cut with the skin still installed. Be vary careful at the beginning where the line is closest to the longeron. You do not want to cut that! The rest of the measurements are for the positioning of the 3/4″ radius at the corner. 25 3/4″ from the front, 1.5″ from the side, and 3/4″ from the nearest rivet.
At the top center, you’re looking for 4 inches from the bulkhead. You use the 821afb reinforcement to draw the line. This is the very tricky part. First I began by hand bending the reinforcement to match the skin as closely as possible. Then I used duct tape, and my measurements to correctly align everything. This took several iterations and a fair amount of tinkering until I was happy. Then I traced the line and removed everything for a final set of measurements. Then it was time for the radius.
I used scotchbrite and a file to get everything cleaned up. There is still a little more cleanup to do. Particularly on the sides near the longerons which will need to be cleaned up after the removal of the skin. Finally, I added the 821abf reinforcement and clamped it in place. This will be double-flush riveted, which is something I’ve never done before, so more to follow on that.