I am an old paper mill welder/ pipe fitter. I started welding in 1979 when I turned 18. I work primarily in the paper machine area and fabricate and repair stainless pipe. Most of the pipe work in my area is sch. 10 s stainless steel, but we also have quite a few carbon steam lines that we maintain as well.
A couple of years ago I bought an old Lincoln square wave tig 355 for my shop at home. Itís got every feature that I ever hoped for and welds very well. But, it started periodically shutting down when I would try to initiate an arc when in stick mode. I can work it steady for days without any problem, but when I am tacking up and it has several minutes of run time between tacks, It may run for 10 hours or it may run 10 minutes before it quits. It will immediately restart with no problem. I have replaced the secondary thermostat and the main contacts just to rule them out. Didnít solve the problem. Iím a better welding machine operator than a welding machine fixer, but Iím hoping someone may have had the same problem and was able to solve it.