High Frequency On No Arc Current

by Chris Thomas
(Jonesboro Ar. USA)

Hello everyone new to tig welding and need some help on making tacks. I have a miller 165 diversion that i tried to set up according to the tack like a laser video. My problem is after the first tack or two all i start getting is the high frequency spark and no arc current. If i pull the torch back 3/4 inch or so from sheet metal it will flash up in the cup and then get arc current. I have triple checked my circut and all seems good. The torch is set up as follows 1/16 tungsten with draw blood point and a no4 cup. I am tacking 18 to 22 gauge mild steel vintage auto panels amps around 110 to 140 gas flow 10 to 15 cfh. I can re-grind my tungsten and it will work again once or twice then back to no arc current. I am using pure tungsten and am wondering if this could be the cause. Went today and got 2 percent thoriated have not tried it yet. Any thoughts would be very welcome.

Thanks

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i feel pretty sure the pure tungsten is most if not all of the problem.

i have had the same issue with the new dynasty 200dx even with 2% thor but it was only because of the extremely low 1 amp start capability.

i think things will go much better with the 2% thor. sharpened