This epoxy putty will plug holes and make permanent repairs in moist-surface or under water applications. Waterweld will even repair leaking fuel tanks! Simply pull off the amount of Waterweld necessary for the job, knead it with your fingers until the two colors are thoroughly mixed, then push the product into the hole. Waterweld will fully cure in 20-30 minutes, and can be drilled, sanded, filed, tapped, machined and painted. Nontoxic and approved by the National Sanitation Foundation for use with potable water, Waterweld turns do-it-yourselfers into professionals.