Originally Posted by duefocena
Thanks for your reply,
The thought of tearing out the deck
of 40' catamaran
sounds so critical. I was hoping to fill it in with got rot
or similar by drilling and injecting
Everyone wants to do it this way, and many try and fail (or live with the failure and call it "fixed"), but the ONLY way to fix this is to cut it out and replace.
Git Rot and the like is not a fix, nor is drilling "pillars" of epoxy - it may feel firm, but it has no strength. The deck of a catamaran has large shear forces at work on it and the core needs to be correctly bonded to the skins or you will have structural problems.
It sounds daunting if you have never done it before, but it is really quite straightforward. Again, not an easy job for a beginner, but one that can be done. It is a relatively easy job for someone who does have glassing experience.
Depending on where the bad core is located and how extensive the problem is, it can be done from the inside, which will save you a lot of finish work on the outside.