Where the
world gathers for metal finishing
Q&As since 1989


-----

Sealing a metal gas tank leak

I have a metal gas tank that has some seepage coming from the bottom around the rear mount welds. Can you seal this without damaging the paint on the top? I've heard that they can be soldered, but you need an experienced person to do so.

Thanks.

Joe Mergl
Mazda - Old Bridge, NJ
2005

---

The coating you need to put on the steel tank is firstly internal, then if you have sealed the tank from the inside you can clean and refinish the outside to prevent rust. I do not remember the names of some materials I used to use on my collectible cars but if you get a copy of Old Cars Weekly [affil link to Amazon] or Hemmings Motor News you will probably see ads for gas tank sealers - they do work. The putty from Pep Boys will plug a hole but not a porous area.

Gene Packman
process supplier - Great Neck, New York
2005

I would suggest J-B Weld [affil links], it will fix most minor cracks in a pinch, and will seal nicely too.

Marc Banks
Blacksmith - Shiloh, North Carolina
2005

Ed. note: letter 33611 is on the same subject and may prove helpful.

---

July 16, 2011

For any one reading this post I would like to add something that I experienced.

I used J-B Weld [affil links] ( a product I really like) on a metal Sears ss16 gas tank. It DID NOT hold the fuel from coming through and continued to leak. The JB Weld was fully cured and the leak point was small enough that I could not see the holes.

I would then not recommend this product for that type of repair.

Tony Feckter
- Bowling Green, Kentucky, USA