welding gas

[col]

what is the benefit of useing argon in stead of Co2

[spanners]

cleaner/tidy  looking welds as it is a better sheilding gas

[lunatic]

I use a argon/co2 mix called argoshield light from BOC. Its cheaper than pure argon. Im assuming we are talking mig here? If not, use argon for tig, I belive.

[brock]

The choice of a shielding gas depends on several factors, most importantly the type of material being welded and the process variation being used. Pure inert gases such as argon and helium are only used for nonferrous welding; with steel they cause an erratic arc and encourage spatter (with helium) or do not provide adequate weld penetration (argon). Pure carbon dioxide, on the other hand, allows for deep penetration welds but encourages oxide formation, which adversely affect the mechanical properties of the weld. Its low cost makes it an attractive choice, but because of the violence of the arc, spatter is unavoidable and welding thin materials is difficult. As a result, argon and carbon dioxide are frequently mixed in a 75%/25% or 80%/20% mixture, which reduces spatter and makes it possible to weld thin steel workpieces

....blagged off of one of the welding sites , pretty much says it all. I would second the argoshield light as a good MIG gas for ferrous work

[col]

Hi
the book i got with the mig welder suggested Co2 for mild steel & argon for stainless & aluminum
         cheers for replys
                         col

[klogan45]

I use argoshield light too. It was recommended by my mate,the welderman that did the structural welding for me and showed me how to weld. His reasons being those as described by Brock. I've never used anything else so can't make any other comment except it's what he uses all of the time unless welding non ferrous metals.
Hope that this will help you Col, but most of all, if you're learning to weld take your time, try not to go too fast, as it appears that lots of us, when we start welding go too quickly, this reduces that all important penetration. This was another tip given by my mate. I hope that I'm not trying to "teach granny to suck eggs", just passing on some advice.
regards
K