I'm fairly new at welding. Although I have "welded" for a couple years, I feel brand new after taking a SMAW course and learning everything I was doing wrong and how much more practice I need, but I'll get there
Back to the point!, my girlfriend gave me a PowerArc 160STH when I started my lessons, so a few weeks ago I got an argon cylinder to start tig welding and it's not been as bad as I originally thought, but I have one important question in my mind; which tungsten diameter should I use? like I said my machine has a max of 160 amps, is there a table that I should be looking at? Any recommendations are welcome. My machine is DC only and I will be welding primarily mild steel as practice and on rare ocassions stainless steel.
John's right, for a 160A max machine, 3/32" alloy tungsten (Thoriated, Ceriated, or Lanthanated) is the perfect all-purpose rod. Not a big fan of Ceriated, myself, and probably why John didn't mention it, but the differences will be insignificant to you until you have many hours under the hood.
I've welded at 20A with 3/32 Thoriated, with a careful long-taper needle sharpening, and while 150A is the "recommended" max, I've welded for short periods over 200A with that size with a short-taper grind.
I did a foot of 1/4 to1/4" last night. There was a lot of mass surrounding the joint. I had the amperage at 210 AC aluminum full pedal much of the time. Quick job, I was too lazy to change lenses. 3/32 2% lanthanated balled up bad at 65% balance. It didn't show in the weld, I wouldn't weld all night with it. With steel I expect 3/32 would be nearly universal. I might keep a stick of 1/16" for the odd need. It should last years. The occasion I see value in smaller tungsten is super low current. Arc wandering is a problem in AC. Smaller electrode can help. DC, it might never matter. I can think of no circumstance where 1/8" is needed with your machine.
