Gas tank welding

[GregWeld]

Since I'm doing the usual "winter" redo on my Nomad... one of the projects is to make my Stainless Steel fuel tank a little narrower... and to add a sump (this Rock Valley tank was originally designed for when I had a carb)...

I found this information about "safe" welding on a gas tank and thought that it is not only informative - but simple and easy.


In order to weld a gasoline fuel tank safely, first remove all traces of fuel. Before welding, wash out your fuel tank with warm soapy water, then rinse with clear water. This should remove fuel residue.

Next, you'll need to remove all traces of flammable gasoline fumes. To remove the fumes from the gas tank, insert small pieces or pellets of dry ice into the filler neck of the tank. As the dry ice comes in contact with air, it will sublimate directly into carbon dioxide gas, which is the fog effect dry ice is known to produce.

Dry ice produces no liquid but rather sublimates from solid to gas. Because CO2 gas is heavier than oxygen, it displaces, or pushes out oxygen from the fuel tank. The fumes will be pushed out of the tank and without oxygen present, the risk for fire or explosion when welding can be eliminated if done properly using this dry ice technique.

[Vegas69]

If I was you, I'd skip all those steps and just start cutting and welding.

[David Pozzi]

Thanks for the info, I've welded on only one or two tanks and filled them with water up to where I welded. Funny thing was, nobody wanted to stay in the shop while I welded on it. I've seen the dry ice done on gas station fuel tanks where they cut and welded in a hatch big enough for a man to enter and coat the tank with sealer to comply with new regulations. The welder is still alive, so I guess it works!

Sooner or later, I'll need to weld on one, so it's good to hear about from other sources.

I think I'd stick a shop air hose in the tank, use a brass valve set on low flow for a couple of hours before washing out to dry the fuel out better.

Hey, once I had a pickup truck tank that was dented in on the bottom. I put a good 100 feet of air hose from a control valve over to the tank, pumped air into the tank until the dent popped out and released it! I"ve done two tanks that way, but no one hung around for that one either!
David

[Tiger]

I welded my Chevelle gas tank once, I put the garden hose into it and went for lunch, emptied it and welded (outside the garage) I was a nervewreck tho :o)

[tones2SS]

Originally Posted by Vegas69

If I was you, I'd skip all those steps and just start cutting and welding.

Sounds like conspiracy!?!?,.......

[Rybar]

Originally Posted by Vegas69

If I was you, I'd skip all those steps and just start cutting and welding.

Todd my stomach hurts

[BBC69Camaro]

I'm certainly no expert welder, but the story my welding instructor told me onc about the tank that blew up and knocked him backwards, has me convinced I'll just buy a new tank, rather than ever weld an existing one.

And this was after "taking precautions".

[214Chevy]

Originally Posted by Vegas69

If I was you, I'd skip all those steps and just start cutting and welding.

Hahahahaha!!! Gee, with friends like this, who needs enemies, huh?? They always said, "Keep your enemies close and your friends closer." Ahh, I know you guys are just fooling around. Good laugh though.

[ssinister]

you can skip most of those steps by doing a few other things.

Drain the tank first. Then fill the tank with any inert gas. No need to remove all traces of fuel if there isn't any oxygen to go with the flame.

Argon, mig gas, even exhaust fumes will work.

[Vegas69]

Originally Posted by Rybar

Todd my stomach hurts

I got a good chuckle as I was writing that one too. I remember Tyler and Russ down at ATS using dish soap and a garden hose and letting it flow for like 10 minutes.

In all seriousness, with you money, pay somebody.