A few weeks ago I put this patch on a badly scratched kayak keel. Since the patch, my kayak has used concrete boat ramps about 10 or more times. Checked it out today, looks great. I am very happy with the Gator Repair Patch and would definitely recommend it. It is very easy to apply in about 15 minutes. We placed the kayak keel up in the sun and in just a few hours it was fully cured. Excellent material!