[AndersK]

Finally I found my problem.
Machine starts with a looong DCEP pulse which will ball a 1/16 electrode in just a few starts. Even a 3/32 melts off but not as bad.

This is one start with was a fresh 1/16 tapered with a flat point. The black spots are tungsten spatter

IMG_20160220_51861.jpg (32.54 KiB) Viewed 645 times

After 5 starts

IMG_20160220_33511.jpg (25.18 KiB) Viewed 645 times

Through a service shop I was told there is a switch behind the panel that could disable the DC start.

Pic speaks for itself, what an improvement that was.

IMG_20160220_15538.jpg (28.12 KiB) Viewed 645 times

IMG_20160222_25278.jpg (31.57 KiB) Viewed 645 times

Pics above was testing at 30 amps.
I have then tested with an almost flat 1/8 at 130 amps, no problem initiating the arc on oxidized aluminum.
Not affecting DC start either.

Pulse with pedal self-healed long before I tried this. Probably myself to blame for not pressing the button hard enough