Using 100% Argon for Mild Steel and Stainless

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I read on another site that a person was using 100% argon gas for aluminum, mild steel and stainless steel mig welding.  I know that 100% argon is suggested for aluminum welding, but what are the downsides of using 100% argon for mild and stainless steels?  On his site he did not go into details.I'm just learning to weld so excuse my ignorance.Darryl
Reply:Quick answer for mild steel...heat (a pro and a con) and cost (mainly a con).  Pure argon substantially increases the heat at any given amp setting over co2 or its mixes.  Argon is more expensive than most alternatives gases or mixtures for mild steel.  I am not sure of the cost of the mixes for stainless, as I dont work much with stainless, especially not miggin' stainless, but I imagine the same is true, but to a lessor degree (stainless generally uses mixes with much higher concentrations of argon than used for mild steel).  As far as I know, aluminum cant be done much any other way than with pure argon (if you are using an electric welder).So, if you want a flexible gas, argon is it...but there are specific mixes that are better suited (cost-wise and heat-wise) to mild and stainless steel.Last edited by smithboy; 09-26-2005 at 06:04 PM.Smithboy...if it ain't broke, you ain't tryin'.
Reply:My experience running argon for steel is it like putting diesel in a gas engine.  It just doesn't work very well.
Reply:I hate to be contrary, especially towards folks that I respect, but I believe Smithboy is mistaken... kinda.http://www.bc4x4.com/tech/2002/gases/Read this article, the meat of it is down a few paragraphs.  It has the specific properties of the various shielding gases.  Specifically, argon will provide a more stable and more focused arc with less overall heat in the weld because it's got low thermal conductivity.  CO2 has much better thermal conductivity I presume as a result of the free oxygen that is created when it disassociates in the welding arc.  A combination of these two gases works very well with carbon steel.  The quantities of each can be altered to adjust the stability of the arc, reduction of spatter, weld penetration, undercut, rate of freezing, and wettability.I'm building a new cart with room for two tanks.  I'm seriously considering the option of a flow mixer and a single tank of either gas rather than using a blend.  With that kind of setup, I would be able to play with different gas concentrations.  I could also go from using C25 for short-arc to C10 or C5 for spray.On the topic of gases, what do folks pay for a fill of C25 in an 80CF bottle?  All the big guys locally charge a little more than $40 for a fill (exchange).  I was out-of-town this weekend and stopped into Tractor Supply Company, which is one of my favorite stores ever.  Where else can you get welding supplies, trailer parts, hardware, and teat dip all in one location?  At any rate, they were offering exchanges on an 80CF bottle of C25 for less than $20.  That seemed pretty cheap to me.-Heath
Reply:Originally Posted by DarrylI read on another site that a person was using 100% argon gas for aluminum, mild steel and stainless steel mig welding.  I know that 100% argon is suggested for aluminum welding, but what are the downsides of using 100% argon for mild and stainless steels?  On his site he did not go into details.I'm just learning to weld so excuse my ignorance.Darryl
Reply:On the topic of gases, what do folks pay for a fill of C25 in an 80CF bottle? All the big guys locally charge a little more than $40 for a fill (exchange). I was out-of-town this weekend and stopped into Tractor Supply Company, which is one of my favorite stores ever. Where else can you get welding supplies, trailer parts, hardware, and teat dip all in one location? At any rate, they were offering exchanges on an 80CF bottle of C25 for less than $20. That seemed pretty cheap to me.
Reply:Halbritt,Don't hate to be contrary when your are right.  The correction is much appreciated.  That's a good, simple, article and explains alot I really never thought about.  I guess I was confusing the focused, deep-penetrating arc that I have experienced using argon with more heat  .  I know every time I opt NOT to change out my argon tank to C02 for mild steel, I have a much greater tendency to burn through.  But, sometimes casual observations can lead to ABSOLUTELY the wrong conclusions, like watching sun rise and set led folks to the conclusion that the sun goes round the earth.  Somedays you're the teacher and somedays you're the student.  Today I am the student. Thanks for the info...If you get that mixing setup working, you REALLY need to post the setup.  I have been looking for something along these lines for a long time.  Gas mixers are DAMN expensive and I would really like to simplify my tank situation.Tractor supply is a good source of gas.  They dont have the absolute best prices, but they are really competitive.  The only better price I have found is through a "family connection" in the gas supply bid'nes, if you know what I mean.Last edited by smithboy; 09-27-2005 at 09:54 AM.Smithboy...if it ain't broke, you ain't tryin'.
Reply:Is it okay to use a Argon/CO2 75/25 blend for TIG?  I recently purchased a bottle for TIG and noticed my gas company gave me a blend. I was expecting 100% Argon.Bugshttp://www.supercubproject.com
Reply:Originally Posted by Bugs66Is it okay to use a Argon/CO2 75/25 blend for TIG?  I recently purchased a bottle for TIG and noticed my gas company gave me a blend. I was expecting 100% Argon.
Reply:Cluna is right.  Take it back.Smithboy...if it ain't broke, you ain't tryin'.