I attached the steel (alloy?) reinforcing ring on the bottom of the FAB, and used a little bit of high-temp silicone to make an airtight seal.
The weather was nice so I also did a bit more covering work. I brushed the tapes on the right aileron, whch gave the RTV a little time to set up.
The other holes in the top of the FAB are for the duct flange for the carb heat air. The back edge will be dimpled rivets, while the front edge will be sandwiched in with the rubber. My hangar Neighbor Danny and his friend stopped by with an interesting Skylane. It has the little canard wings on the front, which seemed a bit curious with my recent cowl work. It turns out that they are actually mounted to the engine mount structure, and while I can’t speak to their effectiveness as aerodynamic surfaces, they sure do look handy for lunch.
I riveted the thin aluminum top to the fiberglass portion of the FAB, then heat-smoothed both ailerons and half of the remaining flap. Since I had to add aluminum pieces to fill the holes in the thin aluminum FAB top, I decided to apply a layer of silicone to help seal the thick top to the thin top. To keep the thick top from sticking permanently, I covered it with a masking plastic.
I bolted the top on to let the silicone form a gasket, then left for the day.