I cut out a large piece of black plastic insullation foam to fill in the portion of the keel area that I intend to eliminate from the final version of the cowl bottom. Then I used spray foam over and under that black rigid foam to hold it in place. I did the best I could to remove the mold release agent (PVA and paste wax) from the inside of the mold, but I did not get a real good feeling that the spray foam was sticking very well. I'll have to wait until it cures to see how that went. I also mixed up the last of my microballoons to use to fill in some wrinkles and bubbles at random locations around the mold. It's beginning to look like I will have to apply another layer of fiberglass to the mold, just to unify all the diverse surfaces in there....fiberglass, microballoons, spray foam, etc. I have also decided to glass over the exhaust stack holes and lay them up flat, with extra layers of fiberglass in the final cowl. I had considered trying to lay up some kind of a flange around those holes, but now it seems better to laminate in a couple of extra layers in those areas and just have flat holes with extra thickness around them.
