Yes, if air hits the molten puddle, it creates an inferior weld and most of the time a porus weld.
A tig welder has to have an inert gas (argon, helium etc) to shield the white hot tungsten from the atmosphere, not to mention the weld puddle form the atmosphere.
Also, TIG gives you a nice sun tan in the winter time - INSTANTLY. LOL
Mig just gives you little black chicken-pock like holes in your skin from the flying spatter.
A tig welder has to have an inert gas (argon, helium etc) to shield the white hot tungsten from the atmosphere, not to mention the weld puddle form the atmosphere.
Also, TIG gives you a nice sun tan in the winter time - INSTANTLY. LOL
Mig just gives you little black chicken-pock like holes in your skin from the flying spatter.