a friend of mine has a gas tank off of an old car that leaks, and he wants me to weld it so it won't leak anymore. I am not a highly experienced welder, and wondered how feasible this would be. also should the tank be purged before welding or even during. any advice would help.
rik
Rik, this is a dangerous thing you are talking about here. It is very easy to kill yourself on this one. I know how to weld them, but I will not pass on that information. I will not let anyone in my shop weld gas tanks (diesal tanks are a different story). Buy a tube of Seal-All, clean it real well and apply as directed. It will work.
JB Weld works well too, but the tank must be empty and no gas dripping through. I've taken a nail and opened the hole up and drained the tank. I applied the JB Weld over the hole and let dry. Applied another coat over that one and filled the tank. I've sold the truck a couple of years ago and the guy is still driving it today. If the area looks thin and pited, you can use some screen from a screen door. You can cut a small piece and place it into the first coat of JB Weld while its still wet, then apply the second over it. Word of caution, no electric drills, no electric work lights. Use your hand and work the hole open with a nail or something.
Lack of time to purge properly was my reason to not weld. It is very dangerous and I don't recommend it either. Mike has given good advise to you, follow it. Even tanks that have been empty for years need to be handled with care and purged properly.
John Wright
double walls and baffles can kill gas tank weldors.
Is a car gas tank that expensive in the USA so as to risk one's life trying to weld it instead of installing a new one?
Giovanni S. Crisi
Sao Paulo - Brazil
GS,
They run from $150 and up depending on the vehicle. I'm in agreement with you, I'd rather replace it than to weld/braze on one. I did have an old truck that I couldn't find a tank for and would have Brazed it back into shape but I JB Welded(epoxy) it instead. Worked fine, then I sold it.
John Wright
Isn't there an official AWS procedure for welding containers that once held flammables?
Yes, there are. see:
http://www.aws.org/cgi-bin/shop/flyall.html?mv_arg=F4%2e1%3a1999
and
http://www.aws.org/cgi-bin/shop/flyall.html?mv_arg=F4%2e1%3a1999
Stay away from attempting to weld on a gas tank. Regardless of how many "safe" ways you hear about. The JB Weld suggestions are the safest. There is also an epoxy mix designed for just this type repair. It is available at most auto supply stores.
Be safe, not sorry.
Paul Gilley, Welding Instructor
Mountain Empire Community College
Just say NO......... DON"T DO IT
If it can't be fixed with an epoxy product a new tank is needed. That is all there is to it!!
By saxdoc
Date 03-08-2003 22:17
my old idiots guide to vw repair says ( believe it or not) rub the leaking area with a bar of ivory soap this only works on pin holes
RIK,
There are alot of people out there with a bizarre sense of bravado. Bill gates doesn't have enough money for me to weld on a gas tank. Buy some JB Weld or have your friend buy a new tank.
In the old days we would drain a gas tank clean the road grit off and clean the metal with muriatic acid and then use a soldering iron that we heated with a cutting torch at a safe distance from the tank then solder the holes, if it is the seam a new tank is needed.I have welded hundreds of cruise a day marine tanks which I flushed with soap and water until no smell of gas was detected then always stuck the torch into the filler hole to be sure of not getting a wooof. but these tanks do not have any baffles and the metal is worth repairing but most auto tanks have alloys
that become contaminated with the newer fuel blends that rot the metal over such a large area that repair is not worth it not to mention that it is such a very dangerous job with huge risks.The average replacement tank is $100.+ my shop rate is $65.+ per.Take a center punch and a funnel and jerry can whack a hole in the old tank drain it and R en R it. brand spanken new man.Nobody goes boom! In the end my advice, Don't do it.Would you weld a tin package of TNT, Same thing!
