Tig/mig sheilding gas

[Skeeter]

I have a miller 210 with the 25/75 mix gas. Mix is all I ever used since I never welded Alum or had a spool gun. Since I have the 250EX now I am wondering if I could use argon for everything in the mig instead of the mix? Any drawbacks other than cost? Reason being I could swap bottles in case I run out with one or the other. Mix gas bottle in the mig is low now so will need to get a refill soon. Ski

[zoama]

Nope, straight argon won't work for steel when mig welding. It won't be hot enough and would give poor penetration.

[DVA]

Nope, straight argon won't work for steel when mig welding. It won't be hot enough and would give poor penetration.

Zoama585 is correct, pure argon will not work well. I have tried pure argon with my Miller 252 and the pure argon does not short arc well at all. I was reading the welders handbook last night on a 4 hr flight, for short arc transfer the best gas is either CO2 or 20-25% CO2 mixed with argon. The CO2 is reactive and helps heat up the weld providing the penetration Zoma is speaking about.

[Skeeter]

Thanks for the info. I learned most of what I know about welding on the job which started in the USAF and then another round in the USMC and then worked for Schneider [Orange trucks] and learned what little I know about welding there. I was good at stick and gas and picked up mig quickly although I wouldn't pretend to know what I'm doing so thankfull for all help/tips/tricks and critisisms given. This old dog loves learning new tricks!! Thanks again,Ski