I thought I might share this epoxy i have been using the past 10 years, I have repaired poly, engine blocks, pump housings, all kinds of holes in fiberglass and al hulls. You mix it like standard epoxy apply then wet your hand with water and smooth it out. We went through 2 ship container boxes of this stuff while working as a commercial diver in West Africa, mostly for repairing gas and oil pipelines underwater, I brought 2 gall back to fl with me and after 10 years I am still using the stuff.
http://www.simcocoatings.com/t-3000.html
http://www.simcocoatings.com/t-3000.html