Thanks Nick, I really appreciate your help!

I think you're right that it was exposure to the hot sun that may have caused it. I had asked the builder if I ever had to worry about the black bottom getting too hot while it was on my roof rack, and he said it shouldn't ever be a problem at all. Oh well.

Does it matter which epoxy was used to build the boat and which epoxy I make the repair with? I'm pretty sure the builder told me he used System 3, but, he may have used West. I have some Evercoat Marine Everfix epoxy here with me at home, if it was built with West or System 3 would Everfix be ok to use?

Thanks!

Bret