Since canyoning in Italy, I am determined to find a good material to protect the knees and elbows of my wetsuits. The wetsuits used there have been customized with a rubbery material that is very hard but still semi-pliable on these spots. It needs to be something that can be spread on rather than sprayed, as it needs to be built up to form a pad. I did buy both the spray on truck bed liner and another rustoleum product to test, but both are spray on so I doubt they will be the solution. Anyone tried anything that worked? Ideas?