J-B Weld TankWeld is a hand-mixable, steel-reinforced, non-rusting epoxy putty that forms a strong, permanent bond for quick repairs on metal. Ideal for rebuilding damaged parts, filling holes, or molding into shapes, it sets in just 5 minutes and is fully curable in an hour. Once cured, it can be tapped, filed, sanded, drilled, and painted. TankWeld cures to a dark grey and withstands temperatures up to 350 degrees F.