My guess is if you've got those kind of holes in it you're probably looking at getting another tank. Mine had holes on the top and was deemed worthless. You can't weld on it to fix the holes unless you like the Don King and shrapnel look. Might be able to fiberglass it, but in my opinion a new tank is in order. If the outside has holes then the inside is going to have a lot of rust and scale that'll clog your fuel supply lines, filters, and carbs.