My only experience is with motorcycle tanks and filling with water really
sucks the heat out making it hard to weld to!
John



Don Lewis n FTW wrote:


I'm told that car exhaust works pretty good for an inert gas. Oil
tankers use their main engines as inert gas generators for the ullage
space above the crude oil level in slack tanks.

it.

===============================================

Have I ever done this? NO. I did get the first idea directly from a
friend who patched car gas tanks. He'd jam the neck of the gas tank
over the exhaust pipe of an idling car, then pop a tennis ball in the
neck as a cork, and start up his torch.

He still walks among us.

He is lucky.... I lost a cousin about 45 years ago in Ardmore,OK. doing
just that... He was a pro. oilfield welder and on a Sunday morning someone
brought in a must do now job... So while the family went to church he
started welding on the top of a tank large enough to get on top of it...
He used that old trick of exhaust into the tank... Worked
for a while on it and the father-in -law drove up..They went into the
kitchen for a little coffee and my cousin left the truck
idling... after a period of time the father-in law left and my cousin
went back to work... The father-in -law heard the explosion as he drove
away... As soon as he struck an arc the tank exploded... The conclusion
was a plug or more fouled out while the engine was idling... I always fill
any tank with water.... Don Lewis