I'd think "arc blow" a myth, if I didn't know so many people who speak of it. I'll reserve comment for now, to see what comes up. As for gas-blow, I always weld the outside of a slip-flange first. That's the critical weld, for structure and integrity. If I'm required to weld the inside, I...

Thanks for the interesting discussion. Nothing new or earth shattering just an issue we all have to deal with when welding on H beams, Corner joints,and 2" thick veed out braces etc. Especially like the video from GE trying to push there AC welding machine 600 AMP whoa must need a hefty breaker...

I've been welding for some time now and always hate losing a great weld to arc blow either on an H beam or wide fillet weld over head. Ok usual practice. Use run off piece at end of weld, Go left then right and fill in ends, Wrap ground cable around beam and pass electrode cable through it to counte...