Constant Velocity wrote:
I just bought an ESAB MIG welder from a friend of mine who was using
it for Aluminum. It's the first MIG I have owned and I have a question
about the shielding gas I should use. The machine was sold to me with
a bottle of pure Argon. I'm going to be welding mostly mild steel, and
read somewhere that for arc stability on thinner materials I should be
using an Ar, CO2 mix. The other day I was trying to weld 2 pieces of
16ga sheet steel with .035 wire and couldn't keep the weld from
blowing through the metal. No matter how I adjusted the machine I
couldn't get it right. I assume that it is partly my newness with this
machine. I was having trouble maintaining an arc at amperages low
enough to keep from blowing through. When the settings were low enough
to keep the metal from holeing I got almost no penetration, and very
tall (rabbit turds) beads. Would switching to a CO2, Ar mix help? I
get great welds on ¼" with this current setup.

Thanks

Peter-

75/25, or C25 is the mix for general purpose MIG, but if you are blowing
through now with pure argon, it's not going to cure that, in fact, it will
be hotter with the CO2.