yeah im not 100% sure on it, but apparently fuel seeps into the metal, like in "pores"??. I remember with the tank im working on now, no matter how much i cleaned it, when i went to put araldite over a pin hole, the araldite would never fill in the hole as the fumes pushed through it.
The...
Ive heard many incarnations of this story, the most BELIEVABLE version i have heard, is to run exhaust gas through it for a while. This way the heat from the exhaust gas vapourises any left over residue from the fuel. Then you are free to weld (this is only hearsay, so i will not be held...
The other small benifit of flux cored welding is you can remove the gas shield on the gun (if it has one) to make it easier to see :)
Ive played with fluxcore welding and its not as bad as everyone says, yes its harder to see with the smoke but the welds can come up just as good as a gas weld...
Hey hey
First of all, good work to that guy that makes this site! nice pics, good explanations etc etc.
I am welding a new bottom into a rusted fuel tank at the moment and while i am well aware of the explosive dangers of this the tank has sat dormant for a few years with no fuel in it...