https://www.amazon.com/Sudbury-Elastome ... QFJF9ACD5J
I tried this stuff on my waders, and so far it is working really good. I first tried Goop with no luck and then tried Goop II....same old poop only different label. Went on like a dream, but didn't hold. The surface that I put it on was cleaned with alcohol and then dried with a hot air drier. Goop I and Goop II simply didn't hold.
This stuff won't fix a large tear, but for a leaky seam it is pretty good I applied it directly over the seam and then worked it into the seam using circular motion with index finger dipped in mineral spirits. It dries fairly quick, but needs at least 23-36 hours to cure.