Permatex 09101 Fuel Tank Repair Kit Kit contains everything required for making professional-quality repairs on metal fuel tanks in just minutes Eliminates the need for dangerous welding, repairing cracks up to 4 inches long and holes up to 0.375 inch in diameter Resin hardens within 8-10 minutes and cures in 30 minutes Repairs can be made ideally at temperatures from 50F to 75F, with the resin curing slower at lower temperatures Not for use on Plastic Fuel Tanks