Back in either '97 or '98, I sealed a Farmall Gas tank using a sealer product I got from an advertiser in Red Power Magazine. I had never done this to a tank before, so I followed the instructions very closely. I cleaned and prepped it as thoroughly as I could. I spent a lot of time on it. The tank had baffles and a few pinholes in it, but I went ahead because I wanted to save the tank.
It was a success because it is still good to this day (probably jinxed myself now
).
It was this stuff:
https://www.theshopproducts.com/prod...nk-sealer.html
Never used it before or since, so the only experience I have with it is that one tank.