I don't know the brand, but there is a two part epoxy specifically made to repair gas tanks, both plastic and metal, while fuel is present. I have used it before to repair a mower tank that still does not leak (6 years) and I sold my CJ 7 with a pencil sized puncture iun the tank repaired with it and the guy who bought it still buys me beers every time he sees me. I got the stuff at an ACE hardware store.