Guest
What you're seeing here is the arc between the tip of an electrode and liquid steel, which is hidden under nearly a foot of slag (the bubbling liquid you see here). This video was recorded entirely by chance, I was videoing other things when I realised that I had a clear view of 'A'-phase. I had to use two crossed polarised filters in order to block out enough light to see things clearly - and yet the arc itself is still blue-white and indistinguishable!
