I've been working on the interior of my 18' Crestliner for a few weeks, finally have all the plywood deck panels fitted and doghouse/casting deck/rear seats built. I was going to leave the wood raw (so it can breathe) and then cover with vinyl, but I'm having second thoughts.
Everything is built out of fir marine plywood so checking is going to happen sooner or later, does it really matter what I use to seal the plywood with? I know glassing the plywood would prevent checking, but I'm not going to glass the plywood. Each finished panel will have 10-20 screws and a jillion staples going into it, so water will eventually get in, even if it's glassed.
Sooo, does it really matter what I use to seal the panels with; poly resin, polyurethane, oil based paint?
I have a few partial gallons of Rustoleum in the garage,,, go for it