I'm sorry I haven't looked through my notes- it may have been Epifanes who gave exceptional customer service, not Interlux. In either case they both assured me that their products would adhere extremely well to polyester/dacron because it was designed with the possi/probability of sticking to polyester resin infused composite boat hulls. I agree with bill that primer usually is more aggressive about sticking to the substrate but is usually cheaper because it doesn't need to look pretty or survive heavy UV exposure. it's also designed for the topcoat to stick to. Usually the topcoat will stick to primer better than the substrate. It seems to me to be a win-win, and it's what I've decided to do on my next kayak, should I ever get things in the rest of my life cleared away enough that I can actually get started on it.

m