To do it right you'll have to remove the tank, not as big a deal as it sounds. Many radiator shops repair leaking gas tanks. Our tank had a lot of small holes on TOP, where it meets the trunk floor where you could not see them. For that repair the radiator shop cleaned the take out and used a liquid sealer that is poured in and sloshed around, then dried. It basically is a tank liner in a can. It works great! Good Luck Bill & Tami Roddick 1964 Imperial Crown 4DR HT 1972 'Cuda 340 1988 Cherokee Laredo 1995 Concorde 1997 Wrangler