Originally Posted by bluesman2333
Alls I can say is the hundreds of boat repairs I did needed epoxy to repair polyester, new polyester would not properly stick to well cured polyester. I'm surprised to find a different story in the car repair arena. (I say repair because that is what it essentially is in this case.)
This is a case of you learn something new every day!
I have to agree that Polyester resin does not always stick to polyester resin that has been cured. I've had cases where it delaminated when making small parts for other projects. The biggest advantage of using polyester is that is sands easier than epoxy, at least in my experience.
As shown in the video using one layer of mat with polyester resin over cured gel coat is a recipe for disaster IMHO. That was a critical joint (floor to body) and relying on one thin strip of chopped mat installed incorrectly is a BIG safety issue in my book.