Jimmy, I had a similar problem with my SS holding tanks from Monorail. The hot water,
soap, and wax tank are one in the same. Its one big square holding tank with two dividers for the
soap and the wax. I had the
soap leak into the hot water portion of the tank for quite a while. I did not discover it because there was not a leak on the floor during this time. The SS weld actually cracked from what I do not know. I ended up using a bonding concrete epoxy on the cracked weld. It was very effective and quite cheap. I ground down the SS to rough it up, and then pumped the two part epoxy into the cracked area. Let it dry over night and voilà!, no more leaks. I also did this to the outside wall of the wax portion of the tank years ago. The chemical (
soap or wax) does have an effect on the epoxy, but it takes at least 7-10 years to react with the epoxy "lifting" it from the SS tank. My solution, dry out the tank, grind it down again, and re-epoxy for another ~ 10 years.
Oh, I did try to weld the tank with my MIG welder without much luck. The SS was so brittle, the welder would blow a hole in the side of the tank. I had an expert welder try to fix one of the cracks with a plate with the same results. He would blow right through the SS.
I priced out a new tank before Monorail went belly up about 7 years ago and was certainly shocked at the $2500 price tag.
I can get you the info on the epoxy if you want to try this.