Answer by
mechtech74 (692)
The absolute superior product for sealing cracks or holes in a fuel tank is Goop SuperWeld. This two-part epoxy product easily bonds to metal, resists chemicals, and dries in less than 3 hours. SuperWeld is made by Eclectic Products in Eugene, Oregon. I found a seller on Ebay who was able to supply a 4-ounce kit for about $13.