Thread: Welding in side 3/4" pipe???

could you drill holes through the outside pipe weld up the holes grind flush effectivly spot welding?

I had ground steel on the larger pipe, after removing first try, so I built up on this with the MIG which burnt off the zinc on the inside of the small pipe then I filled it up with weld. So problem solved.
What would people that know what they are doing do?

Danger alert!!!

Zinc fumes from welding galvanised metal is really unhealthy and can cause all sorts of metal poisoning problems. Zinc is bad enough, but sometimes they also have added cadmium if its not intended for food grade service, which is nearly as bad as mercury.

Secondly - zinc pretty much 'poisons' any weld. If you were to grind off all the galvanising before trying to weld you might get a decent weld if you were welding to the outside - but if you leave any inside it will catch fire & you will have clouds of toxic metal smoke going everywhere along with a pretty greeney-white light coming out the ends 'Old timers' used to put the gal. pipe in a wood fire until it got hot enough to set the gal. alight - they didn't know about the metal poisoning & probably died of something like smoking cigarettes instead..........

You would be better off, and probably safer, to try to get a short off cut of black thick wall tube or a bit of solid rod & drill it out to the right size.

Originally Posted by bsrlee

Danger alert!!!

Zinc fumes from welding galvanised metal is really unhealthy and can cause all sorts of metal poisoning problems. Zinc is bad enough, but sometimes they also have added cadmium if its not intended for food grade service, which is nearly as bad as mercury.

Secondly - zinc pretty much 'poisons' any weld. If you were to grind off all the galvanising before trying to weld you might get a decent weld if you were welding to the outside - but if you leave any inside it will catch fire & you will have clouds of toxic metal smoke going everywhere along with a pretty greeney-white light coming out the ends 'Old timers' used to put the gal. pipe in a wood fire until it got hot enough to set the gal. alight - they didn't know about the metal poisoning & probably died of something like smoking cigarettes instead..........

You would be better off, and probably safer, to try to get a short off cut of black thick wall tube or a bit of solid rod & drill it out to the right size.

$100 for a proper mask is spose to protect you from the fumes, bought one from the BOC mob here and it works great. Personally I stay away from Gal and try to use blue (not a fan of black because of rust)