[Markus]

Sound familiar to me. I tested these bigger cups on open root on stainless pipe. With massive gas flow from the torch, it created some kind of vortex with out coming root gas (argon). Always messed up my tungsten and suffered from deflected arc. Problem was solved with changing back to number 8 cup and lowered gas flow.



What comes to steel purity and especially with those that are manufactured in China. Here is a good sample
Welded with orbital and with same program as always. Pipe to pipe welds just fine, but these little suckers. God damn they suddenly starts to over penetrate like maniac. Probably sulfur or oxygen content are way too high.
BTW. Notice deflected arc at the end of the weld in first picture.

So that in mind it's not always welders fault that if manual welds don't go as planned. Materials differ! Even expensive ones. Sorry little bit off topic