[philb]

I'm not aware of any water cooled welders. It's possible though. Water and electricity usually doesn't mix unless there are special provisions made. If I were going down that path, I'd try submerging it in mineral oil. I have a really old xray machine that has its coils submerged in oil.

The next step for me will be a DC capacitor to smooth the arc. Lincoln Weld arc 100 uses that setup. I don't think They were made to resonate. Maybe someone who knows will chime in.

The unit has been running 30 degrees F above ambient since the addition of heat sinks so there's no need in going further with cooling. I used a HF temperature laser to check it immediately before and after welding. This is still hard for me to believe that heat sinks actually made such a difference especially with no heat sink compound. I guess that's why necessity is the mother of....