Rudder tip fairing. I decided to practice attaching the rudder tip fairing with screws instead of rivets, since the rudder tip will be high and flaws harder to see. If I don't like it cosmetically when I am done, I will glass over it anyways. It turns out to be a little tricky to do this well. I don't have the proper carbide fiberglass countersink for the screw size, but I have one for AD3 and AD4 rivets. So I drill the prepunched rivet hole into the fiberglass with a #30 drill, then take the fairing off and use the AD4 countersink to recess the glass enough for the screw head. Then, using a nutplate with a screw in it as a template, drill the nutplate attach rivets into the glass. Finally, I used the AD3 carbide countersink to recess the nutplate attach holes. Lots of work compared to riveting the fairing on.
