I just got a new fangled TIG cup made of Pyrex glass. It's pretty cool. Did some welding and I actually looked through it because of the cramped quarters. Got to wondering how that glass can take the heat. Pyrex is good, but it must be rediculas hot there. I figure the constant supply of argon must keep it cool. Then I thought, what if I run out of argon in the middle of a weld. I've done this before and the tungsten gets burnt some. With the glass, I wonder if it will explode. Anybody have experince with the glass cups?