Hey guys I'm in a pickle here! Im welding chromoly for the first time and that well actually other than when i weld it it gives off a awkward smell and I just mention this to see if this related to my problem. Now first thing is the fact that im getting horrible contamination when welding aluminum. So far what I have done...Checked for Leaks (argon) , made sure tank is argon, tried 3 different tugstens(2 2% Lanth-1 Pure), tried diff. filler rod (new bag of 4043. changed collet and body(using screened collet body), used 6 7 8 9 cups, turned cleaning action up to the point of tungsten melting, tried gas flow to point of arc blowing out and down to no gas, also tried 4 different pieces of stock all 6061 t65 mill stock fresh and clean. So this is weird i had my machine dialed in and changed nothing before all this trial and error. since this worked great the only thing I have changed is I exchanged my argon tank for a new one. now it has to be tank in my eyes it worked fine just before so am i wrong? What else could it be? does anything happen tanks that could cause peppering, contamination? thanks zach