Eric R Snow wrote:

The oil has been leaking for a long time. I thought it was something
else. If flashover occurs will it act like a short? And would this
prevent any high frequency at all? I ask because the high frequency is
weak and always has been. But it is there. The spark gaps work. But
every Goldstar machine I've used has been the same. Maybe they all
have defective caps. On Lincoln machines you could see purple sparks
emanating from the tip of the tungsten and dissipating into the air.


No kidding! When I first started learning to use my Lincoln Square-Wave
TIG 300, I was actually WELDING with HF only. I never got the electrodes
close enough for the main welding current to flow! That was awesome that
it could melt thin metal just with the HF! Under the right conditions, I
can get 1", sometimes even 1.5" arcs from the HF, it looks just like those
plasma globe things. (After an hour of fooling around, I discovered the
main welding current by squeezing the finger control more, getting the
electrode closer, and getting a real arc to develop.) But, clearly, there
is NOTHING wrong with my HF generator.

I know that the HF system is the reason many TIG welders get junked
or converted to stick-only. The main transformer is generally very
robust, but the caps, HV transformer and spark gaps all need to be
maintained.

Jon