MOPED ARMY

take it to a boat repair/sales place, cover the hole with tape from the outside, have them pump in about a cup of fiberglass resin resin. tilt the tank so the resin sits on where the hole is... once it fully cures (half an hour or whatever), youre good to go. iv fixed a car tank and a few rusty motorcycle tanks this way, it works great and is fairly cheapv(less than 10 bucks most of the time). just make sure you get all the oil and grime outa there so the resin sticks.