Quote Originally Posted by Reefgeorge View Post
If I do replace the entire core, it would seem that I need something along the edges for the screws to bite into besides coring or the end grain of marine plywood so the teak strips or fiberglass flat stock seems reasonable. Would poured thickened epoxy like Scott suggested also hold screws well?
Epoxy is hard which equals brittle. It is not what I would want to be screwing into really. Will it hold? yeah. Will end grain plywood hold? yeah.

If you wanted to get really tricky with it you could rip a few thin strips of marine ply and put them on the screw hole edges where the face of the plywood would be out to contact the screws.