Crappy bead w/ Miller Spoolmatic 30A

My experience with trying to weld automotive aluminum is that there is too much oil/dirt/stuff in the metal. You can clean and clean, but you need the power of a TIG to really create a molten crucible where it can boil out. And then there's the contamination that's coming in from the back of the piece being welded. I never had much luck with my Miller Spoolmatic except for welding 1/4" or thicker flat aluminum in a flat position. Then the welding characteristics would change as the base metal got heated up.

I hear of guys all the time who can weld aluminum with MIG. I never had much luck with it.

Steve

Sounds like the Argon isn't reaching the nogas nozzle or is heavily contaminated. Have you;

1. checked for leaks?
2. measured the gas flow at the gun?

The soot either side of the bead is actually carbon deposit from decomp of grease either on the wire or the job, and actually indicates at least some gas is getting through.

What arc voltage and current are you running at? A rule of thumb is Arc Volts=14+(Amps/20)

Oops! for Nogas Nozzle, read Gas Nozzle! (Freudian slip!)