Re: Transome rot can I extened life
PT ply exterior works, glass it both sides and seal the edges.
But you have to dry it first.
my transom had big time reinforcement, 3/8th alum plate on the outside , thru bolted w/ 1/2 " stainless all threaded rods to a 2x8 cross brace which was bolted to the stringers with angle brackets, bottom line, he probably paid good money to have it done and it still failed, fixing it right wasn't so bad.
I cut the splashwell off, left the cap on, poured a seacast transom after gutting it out with a chainsaw from the top.
Then I got ambitious and cut the deck liner out, leaving 3 inches around the edge of the deck, replaced 50 gal tank and plumbing , re-cored the fiberglass deck and replaced stringers.(18" tall x 8 feet long)
All new bilge paint, new bilge pumps etc. I don't think it was much more than $2K even with the composite transom. But who keeps track?
Go snag a couple sheets of ply now, set it to dry and do some exploratory surgery with a chainsaw.
