AC Tig welding on Stainless

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For a hard facing application, I'm required to use AC welding on stainless, which I understand is not typical, but it's what's required by the WPs to keep penetration to a minimum.  My questions is that my inverter TIG is cutting out if I don't have the balance to 85% neg and 200hz... My initial conclusion is that since Stainless is a poor conductor of electricity, on the positive half of the wave I'm not maintaining electron flow.  Anyone experience similar situations?
Reply:I have no advice, but im curious.  Wouldn't DCEP be a better choice for minimal penetration?Have we all gone mad?
Reply:Interesting concept, to use AC on TIG to limit penetration for hardfacing or cladding applications, but I'm not sure it is logical.What affects penetration?  Amperage, polarity, shield gas type, arc gap, travel speed, torch angle, tungsten grind, weave, etc.All the above parameters affect the power density of the arc, that is how many watts (amps x volts) are transferred to the base metal, and how small is area the power is dumped into (arc diameter).The TIG arc transfers energy through the flow of electrons from the electrode to the workpiece, so DCEN transfers the most energy, AC transfers less, and DCEP transfers very little power to the base metal.  For example, a 3/32, 2% thoriated tungsten can carry up to 250 amps on DCEN, 180 amps on balanced AC, and only 30 amps maximum for DCEP, because electrons are flowing to the tungsten in AC and DCEP.For a given current setting, and holding all other variables constant, changing the polarity affects the efficiency of transferring arc power to the base metal.  It is just like using DCEN and turning the amperage setting down, except the tungsten is getting overheated when switching to AC or DCEP!  So, to reduce penetration, use DCEN and reduce the amperage.As mentioned above, it is not just the power to the work piece that affects penetration, it is also how concentrated or spread out area of electron impact is, that is the power distribution.  For example, a very short arc length helps concentrate the power and give deep penetration, and vice versa.  So does changing the polarity also affect the size of the spot that the power gets dumped into?  I'm not sure, but if so I think this would be a minor affect that would not sway me to use AC or DCEP to limit penetration for cladding.
Reply:Uhm, well I thought this was an interesting topic, maybe not, no comments in several days,  not even from the original poster.
Reply:You might have scared everyone off with your initial respons =P