Saw some article on the web saying that its more common to use A/C for TIG, and very rarely DC. Hummm. I always use DC-EN for steel, stainless, and anything BUT aluminum. So, is it possible to use A/C on mild steel? How would that work? just like aluminum, let your nice pointy tungsten ball up, and have at it ? Anyone try A/C tig on mild steel ?
Well, I for one have never tried it - AC on mild steel. I guess it would work - but can't see where any advantage would come from.
You don't desire the extra heat in your tungsten and loss of the sharp focus of your arc with the tungsten balling which comes with AC. You only use AC when it makes welding possible where it would otherwise be impossible - which for Al is about the cleaning of your metal of oxide on the reverse current, allowing the weld to flow.
You get nice welding of mild, steel, stainless steel (and most metals) on DC with TIG. Small narrow cool deep-penetration welds, I'd characterise them as.
'nother advantage is that DC TIG is silent - just a gentle hiss - so you can settle down, put some sound on and settle into a nice head-space and get your TIG'ing done.
I read that somewhere too. Somthing about running high freq and high duty cycle to get a more focused arc. Well, I tried it on steel and all I got was a balled tungsten and a crappy looking weld, but I am pretty new to this.