Quote Originally Posted by Stumpkiller View Post
It is an epoxy gel coat on fiberglass & carbon cloth.

Gel coat is miserable and expensive but, happily, there are dozens of compatible kits, like Yobuck said, for boat repair.

You can even do a color match.

https://www.amazon.com/Evercoat-Gelc...oat+repair+kit

But if you have to build the surface up any hard two-part epoxy will give you the bottom/filler. You want a two-part putty (easier to form to existing curves) and a product like PC-7 comes in small amounts (to ounces is like $5). Hardware store item. Cut a piece of plastic to make a spatula and keep some 91% alcohol on hand to clean up any "overages". It has a nice working time as well.

https://www.amazon.com/PC-Products-1...ds=epoxy+putty
I don't do any visable fiberglass repairs on my boat myself, but they have been done by a professional, including re gel coating, and it cant be detected.
I do use a fair amount of the basic 2 part epoxys on various small projects. Just last week i used the 2 part putty type epoxy for the first time and it was PC7. Id recommend automotive type body filler over that, but any of those types will require painting.