DCEP And DCEN...

[Erie Fred]

I regularly swop between EP and EN normally 50 times a second.

Well....I do it 60 times a second.....so there....

 

[premmington]

My electrical guess is as the water vaporizes, you get a steam which is inundated with carbon dioxide from the flux coating and metal vapor being mixed with the steam, its electrically conductive so the arc will typically use this to travel to ground in other places than where you wanted it to go. DC current typically is prone to arc blow due to its continuous directional electron flow.

Flowing cold water...

Pure water is electrically neutral. However, when water (like groundwater or seawater) flows through porous materials or the Earth's magnetic field, it carries dissolved ions (like salts)

 

[Turbo]

Well....I do it 60 times a second.....so there....

But at a lower voltage!

 

[Erie Fred]

But at a lower voltage!

Not really, we still have xformer welders, so we still get 80v at the electrode.