I have finally completed my
project. I wound up doing it without major re-engineering. The outer frame is somewhat different than I imagined prior to
removal. It has a raised central area and lowered lips at the edges. In cross-section it is somewhat like a top hat. The thicker central area allows deeper insertion of the screw threads. The outer flat area lands on the
cabin surface. The Plexiglas originally fit into the inner flat area. I increased the width of the Plexiglas to cover the raised area. I cut the notches for the fasteners oversized to allow movement. This leaves about a 1/8 inch wide by 1/4" deep recess which I then filled with silicone. I first mounted and sealed the
bronze outside frame to the
cabin side with 4200, holding it with clamps. It is not ideal as the wavering saw cut from manufacturing results in 1/8" bearing in places. Once set, I then installed the Plexiglas and inner frame, initially using longer machine screws with wing nuts to clamp it down, then sequentially replacing these with appropriate length machine screws. The recess between the Plexiglas and the outer frame was about 3/32 of an inch which allowed a nice bead of caulk. The label for 4200 and 5200 cautioned against using it with
acrylic.
The increased thickness of the assembly due to landing the plexi on the raised section does not seem to have any ill effect as I was still able to clamp and compress things as before.
Incidentally I also put a layer of Formica across the
water damaged
teak veneer
plywood. This lightens up the
interior remarkably. I found that Wilsonart brand off-white laminate is a perfect match to the
headliner gelcoat color.