Looking for a product

[eggsuckindog]

I saw an infomercial on a spray sealer, I guess rubberized? the other night. They cut the bottom out of a jon boat and put a screen door in, sprayed it on and showed it sealed and floated. Forget the name but they also wanted 19.95 a can but I have an idea I want to use it on - anything kinda like it out there???

I want to coat the inside of my scupperer tubes