Re: 51Packard's....51 Packard

Posted by Larry51 On 2012/4/8 19:00:38

There are some differing opinions about what gas or gas mix to use. A local welder was the bloke who told me that straight Argon is too cool for MIG on sheet metal. I was having problems using 100% Argon - not much penetration and weld sitting high despite any and all adjustments to current & volts.

Looked up Welders Handbook (Richard Finch p. 100) who says: 'Ask your gas supplier to advise you on the best mix for MIG welding. So-Cal Airgas makes a mix of Argon and Oxygen for MIG welding'.

Elsewhere he says: 'CO2 is used instead of Argon because it is effective and inexpensive. Where high quality welds are required in 4130 steel a mixture of 75% Argon and 25% CO2 may be used'. He also mentions that 'CO2 has superior heat conductivity' but says 'regardless of what gas is used . . . . different gases use different flow meters (gauges) . . . the CO2 must have its pressure and flow regulated'.

So if you use an Argon or C25 mix you might need a different gauge to CO2. I just use the same one, my gauge doesn't state whether it's for C25, CO2, 'Gold Gas' or pure Argon. All a bit confusing but CO2 is an option that might help get better penetration.