Fixing a Sainless Steel Water Tank

[LJH]

I had tried adding this to an older thread but it was not coming up in the listings. Aplogies in advance if there is duplication.

I am not familiar with welding stainless steel. My water tanks are 28 years old and are seeping at the spot welds where the baffles are tabbed to the tank wall as well as along some of the welded seams. I am in a location without a marine industry and dealing with workers in a language a second language for both of us. They did some re-welding along the seams and the tank is leaking around their repairs, perhaps at an even faster rate than it was before.

The company here now says that my tanks are too old to fix! They say will have to fabricate new tanks for me. From the look of the tank that I managed to remove, it had not been previously repaired. They re-welded the area where the seam was leaking and not the whole length of the seam.

I have some questions.
Is this true about stainless steel? Will it become to thin to work with? Is it possible that the re-welding that leaked was poor workmanship or material failure?
Is there a specific method or equipment that should be used to make this sort of repair?
If I have to have a tank fabricated, what thickness steel should a 45 gal/200 l tank be? The shop here says 2mm!
For those who have used JB - weld. do you think it would work on a weld of 335 degrees angle.

Any advice or pointers will be greatly appreciated.

[AiniA]

JB Weld is incredible stuff and I have not found a job that it could not do. I don't think your tank job is a problem, BUT I wonder if there is a problem with using it in contact with potable water?

[Leebob]

Sounds like poor craftsmanship. They need to well past the leaking zone. Are they using stick welding or a TIG torch? The thing about SS is it pulls real bad. When you make 1 weld it would have affect on a area a few inches away. Especially on thin material

[seacap]

Stainless steal as a metal sucks. When it goes bad, it's bad. You can try to do some temp repairs with JB. But you will need to replace the tanks. SSCorrodes from the inside out. So trying to repair SS that was corroded is a losing proposition. The welding shop is correct.

Don't know about the thickness.

I just had my SS tank fail at a seam after 25 years. But hey, 25 years ain't bad. I used a flexible tank until I could get new plastic tanks that were made for the boat.

[Leebob]

Read the thread on the forum, fixing a SS water tank. Lots of input on welding. Also the use of job weld.