I used duct tape to hold a hull and deck together for glassing the inside seams, and found that it stretches too much when under that much stress. Later i found out that the best tape to use for clamping stuff is one inch packing tape, the kind with six or seven threads running the length of the tape. The threads prevent it from stretching at all, so you can use it in high pressure situations. just my two cents. be good. -tim