It's kind of hard to judge, not sure if I didn't let it set fully or properly or what. From the directions I read for things like vinyl seat repair, it seemed like it would set pretty firmly. It definitely held the gash shut, but if I ran my finger against the layer on top I could kind of roll/peel it away as it felt kind of soft. On the other hand, playing hockey didn't seem to cause any wear to it, so I just stopped touching it and never really thought of it again.
So I think it is the right tool for the job, it just may require some practice or expert advice. Could also be that the cortech skin just doesn't let the goop adhere the same as vinyl?