hole in gas tank??

hello i have recently noticed that the p/o drilled a hole in the gas tank (what ever reason) and then patched it with putty of some sort and it has begun leaking. now my question is what is the best way to fix the tank the hole is on the frame rail whatever you call it so it doesnt have to be pretty just hold gas for longer than the putty (less than a year)

The most permanent repair would be to braze it. You MUST empty and purge the inside of the tank very well before doing so to ensure no gas fumes are in there or KABOOM. A shop that does automotive repair should be able to do this. Ed