WATERWELD will plug or seal practically anything that leaks. It will patch holes and cracks and mend almost anything that is broken. It is excellent for rebuilding or fabricating parts and as an all-purpose adhesive for metals wood fiberglass masonry ceramics PVC and ABS. Permanently repair holes gouges cuts ... even seals rot in fiberglass and wood. Cures under water. Safe for use on lines carrying potable water. We should really call this amazing product "The Miracle Welder" because you can use it to plug holes and make permanent repairs under water and in gas tanks -- while they're still leaking. WATERWELD can be applied under water; surfaces to be repaired do not need to be clean and dry. WATERWELD putty "mushrooms" through and around holes grabbing the edges to hold securely then hardening for a permanent seal. WATERWELD is approved by the National Sanitation Foundation for use with potable water (meaning you can drink safely from fresh water pipes or utensils repaired with it). Tensile Strength: 6000 psi. Density: 15.8lb/gal. Compression Strength: 12000 psi. Shear Strength: 700 psi. Hardness: 65-75 psi. Resistant to: 300° F. Modulus of Elasticity: 6 x 105 psi.