Aquaseal Seam Seal
Used on polyester thread sewn as a deck seam on marine…
Price Paid: $6
Used on polyester thread sewn as a deck seam on marine grade vinyl. Tested uncoated sewn sample and water ran through the seams without hesitation. Dried cover and let sit for 24 hours then coated according to instructions. The cured cover held water with only one or two slow drips in the hundreds of stitches.
I wouldn't use it to make vinyl fabric buckets but to keep water from reaching the seat foam in boat seats this worked very well.