How bad is the damage?? Is it like a hairline crack that is causing the drip?? I'm just asking because I had the same issue. Actually had two hairline cracks in my gas tank and what I did was drop the tank, dry it completely out, and use a product called Red Kote. It's an interior gas tank sealer and you just slosh it around in the tank to cover the whole bottom. From start to completion, I let it take about a week. A few days to clean out and let it ventilate, then a few days to let the Red Kote sit and dry after coating.
You might wanna check out Doja's idea then. I know when I had the cracks in my tank, I tried J.B. Weld, Quik Steel, Seal All, etc. Tried them all, but with the constant gas seeping through, it prevented any seal no matter how resistant they claim to be on the packaging. I even tried to patch them with no gas in the tank at all, but the minute I put gas in and started driving, the pressure pushed right past the seal and started dripping again. The Red Kote is going on a year now with no drips.
Just giving my two cents, but I'll see if I can think of any quicker ideas for you