How do I get pretty TIG welds?
 

I know that we have a couple of pros here.

I was just curious as to why my TIG welds aren't the pretty irridescent colors. They are functional, but are always dull grey on mild steel or stainless.

Too much heat?

Wrong filler? Too small of a filler rod?

Not enough Argon? Too much? I keep it around 23 cfh.

Too small of a cup letting the argon shield move?

On mild steel I use ER70S-6, copper clad, usually .035 on .060-.125 wall

Stainless I use 309L as I have it left over from my manifold build which was 316 to mild steel.

Machine is a Miller Syncrowave 180.