J-B Weld WaterWeld will plug or seal leaks and patch holes and cracks in almost anything. Ideal for repairing plumbing, fuel tanks, tub and shower, drains, pool and spa, boats and potable water tanks; setup occurs even under water. After curing, it can be drilled, tapped, filed, sanded and painted. WaterWeld has a set time of 15-25 minutes and sets hard in one hour. WaterWeld cures to an off-white color, is rated at a tensile strength of 1300 PSI and will withstand temperatures up to 300°F.