Originally Posted by spidermonkey
Boat : Avon 5.5 SIB - 1970's !!
The plan is to pull the transom out, get hold of a couple of sheets of marine ply, laminate the ply together up to 40mm thickness. 'Borrow' next doors bandsaw to cut the new transom. Thinned coat of varnish all over transom to seal it. Glue it back in place. Apply lots of coats of varnish.
Sounds simple, can't imagine that it will be.
Seems straight forward enough to me .. you have a template or as good as.
I sugested the epoxy idea to coat your new transom which in original post you said you would be making of m.ply.
Id still go with this option as a fiberglass transom is going to be a messy and expensive job i'd imagine.
perhaps someone else can advise...