Newbie here. just been given a old Hobie 14 with some serious damage to one of the hulls which I'm attempting to fix up. The worst are a couple of holes about 4-6" in size where the trailer ends punched into the hull during a typhoon.
Once you have the backer material iun pkace, I would build up the damaged area using woven roven glass then 4-6oz glass cloths. finish the last ( outer layer) with the light weight cloth . Use Vynalester resin. Stronger then Polyester but cheeaper than epoxy.
I have been getting all kinds of great ideas on how to repair them from these forums, and the "this Old Hobie" articles on major repairs and blind repairs but there's one point I'm not sure on. I will be doing these as blind repairs. I will follow the method in the article on blind repairs - remove the damaged area of fiberglass - but once I have the backing laminate in place am I to layer glass up to thickness of the hull until it is flush with the exterior or use foam as in the original construction? Bear in mind the holes will likely be about a 6" diameter so they are substantial. Rick Buchanan advises this in his "Major Fiberglass Repairs" article but not in the blind hole repairs one...any pointers are very welcome before I get into it!