My only experience with with a tank was as follows: I got a crack in the
same area. I thought that I would weld a patch over it. When I hit it with
the wirefeed, it blew a hole. I got a small piece of plate, and patched it
oversize to the leak. I cleaned all the paint off, etc. I welded it on,
and it looked pretty good. It still leaked. I ended up selling it at a
yard sale, with a sign that the tank leaked, and it was for parts only. I
don't know, maybe the guy who bought it got it fixed.

As said before, there may be some liability in fixing one, and it may be
something that comes back to bite you. If I ever have another go out, I'll
just go get another. Fixing them is a toss up. It may last for years, and
it may blow up tomorrow. And they always die at the worst time.

Steve