Kayak Crack Repair

jgaleazza wrote: ↑ OK, I need some input. My kayak developed a crack along the inner edge of cockpit opening. Did some googling and reading up on epoxies like JB Weld. I've tried to repair the crack with JB Weld Marine Weld, thought I had fixed it but the repair failed last week when I was using it. I thought I had done everything right, sanded the surface, wiped clean, left to cure for a few days but it still failed.

Does anyone have input on repairs to kayak material (Polyethelyne?) that will hold. The repair needs to be strong (both the material itself and the surface bond), but flexible. Is JB Weld Marin Weld the wrong epoxy?

P.S. I have seen videos of people who have used plastic welding kits (basically a hot knife) to remold the plastic back together but I'm not comfortable enough with that method yet.

jgaleazza wrote: ↑ I gave it one more shot with the JB Weld, just did it slightly different.

I did the repair in multiple layers (3 to be exact)

First layer I just filled in the gap between the material.
Second layer I went over the first layer plus about 1/4 inch on either side
Third layer same thing went over the previous layers plus about 1/4 inch on either side.

I lightly sanded between layers and cleaned with alcohol, and used masking tape to keep the patch clean (peel the masking tape while the material is still wet but not runny to avoid having the patch pull up with the masking tape). I also used a piece of wood (paint mixer) and clamps to help keep the hull to as close as the intended shape as possible. The biggest difficulty I had was applying the patch to the inside portion of the hull as I can't easily get a view of that area. We will see what happens next time I put it in the water and if it holds a bit of spray paint and clear coat should blend it into the rest of the kayak nicely.