As my bulkhead project is in its final stages in my San Juan 28 'Enterprise', i need some advice. I have pulled out every piece of wood on the interior and used as templates for new Jorbet Marine plywood. All pieces are installed with stainless wood/fiberglass screws and bolts. i am now looking at some rough cuts as i walk around the galley. My question is can i fill and fair the gaps which meet the cabin roof with marine grade fiberglass body filler? i plan on taping straight clean lines on the bulkheads and cabin roof before i begin working with the material. Even though the deck is 100% firm, i want to know if i will have any problems with the deck naturally flexing especially while under sail. This seems like a decent option for me, rather than going the painstaking route of cutting 1 3/4 pieces of oak trim to conform the the cabin roof.