I just replaced the
cabin top in my Coronado 25. It had a fiberglass topside with 1/4
marine ply adhered to the underneath, or deckhead. I wish now that I used 1/2 or even 3/4 inch ply as the replacement as the deck still oilcans under my weight.
With 5'6"
headroom and me being 6'3" and using an antique 7" angle grinder made the job pretty awfull. It can be done but you got to love your boat.
Don't be stingy with the thickness of the replacement ply. Use a resin
epoxy, doesn't matter what brand. I found success after the third attemp with a resin
epoxy. Damn the expense. (I am a
cheap bastard). Good luck to you and keep us posted on your progress.....Allan