Welding On A Used Metal Gas Tank

[Spencer]

Got out my spare Argon tank.

Rigged up some tubing to connect the Argon fitting to the air fitting.

Did a big blast and then slow purge For a while, then turned it up again before I started welding.

[Spencer]

This was like Welding a moving pendulum.

If it was better weather I could have moved some stuff outside to put this on a work bench, but I didn't.

I burned through the top of the tank and had to weld In a mend plate below the new bracket.

Not my finest welds by any means, but it's done.

[JWS]

Now what have you done to prepare the inside of the tank? Any coating has burnt and is probably peeling. It will find its way to your gas tank and carb. Will rust from the inside out.

With that said. Glad to see the final result as that meant you survived. Some things aren't worth dying over. This is one thing I have eliminated doing or helping others do.

[digger doug]

I only cut on tanks, so take this as you will.

I believe if you filled it with water, the large cooling sink of water would have
helped you from burning thru.

[Ironman]

Originally Posted by Spencer

Got out my spare Argon tank.

Rigged up some tubing to connect the Argon fitting to the air fitting.

Did a big blast and then slow purge For a while, then turned it up again before I started welding.

Good. That's the right way. When I am using exhaust the truck stays running though out the job, so when you cut into it you get exhaust coming out at you. Argon works the same.

[FabberMcGee]

I have welded many gasoline tanks over the years. Some with several gallons of gas inside, usually in a boat where it is a big job to remove the tank. I always charge them with CO2. It's cheap and heavy. It fills the tank from the bottom up, pushing out the lighter gasoline fumes and oxygen and has a very distinct (annoying, stings your nose) odor. I make sure the vent is at the very highest part of the tank and there are no places to trap fumes in a high corner or weird shaped place. I let the Co2 flow at a good rate until when I put my nose in front of the outflow stream it is definitely CO2 coming out. That way the tank is completely full of non combustible gas and can not explode.
I leave the CO2 flowing while I weld and have checked the outflow with a little propane torch. There is enough CO2 coming out the end of the vent hose that it will put the flame out for about a foot distance before it mixes with enough oxygen in the air to support a flame.
The first time or two I was pretty nervous about it even though I was sure it was safe. But, I always look it over carefully and cautiously before I weld. Not recommending that anyone else do this, but that's how I do it.

[Spencer]

Originally Posted by JWS

Now what have you done to prepare the inside of the tank? Any coating has burnt and is probably peeling. It will find its way to your gas tank and carb. Will rust from the inside out.

With that said. Glad to see the final result as that meant you survived. Some things aren't worth dying over. This is one thing I have eliminated doing or helping others do.

I had not thought about or planned on doing anything to the inside of the tank. If there is something I can to do the inside of the tank to prevent an issue I'd like to hear about it.

Here is a picture taken through the filler cap. You can only see the manufacturers welds in this photo, but I'll try to find my tool I use to look inside walls to see if I can get a decent pic of the areas I welded.

[digr]

I have used this and it works good!

[Spencer]

Originally Posted by digr

I have used this and it works good!

I ended up using a similar product from POR15. I finished this project back in April, but somehow lost all of the pictures.

In addition to welding on the new D-Rings and that second matching bracket, I also ended up replacing the fuel hose with a more flexible black rubber fuel line as opposed to the stiff plastic yellow hose it came with.

I'll get some new photos in a few weeks when I take the tank to the gas station to get it filled up.

[NOBLNG]

Glad you got it done safely! Having never welded on a fuel tank, I would have have made a couple of band clamps. Something like 1/8”x3” strap iron. The lifting lugs could be welded to them before bolting them on.