100% argon for mig?

[Discoman]

can I use just pure argon for mig?
i got a linde welder mig setup for really cheap, it included a regulator that is for argon only.
is pure Ar fine or should i go with a Ar/CO2 mix or even trimix?

[trial&error]

it works, runs alittle cooler than c25 and not quite as shinny, probably not up to code though. I can run straight argon through my mig and tig, c25 tends to eat up alot of tungsten on the tig. lessons learned from using one bottle for 2 processes.

[Rocky D]

You won't be happy with the results using straight Argon, tends to be globular, rather than a nice short arc transfer. C25 should work just fine in that regulator. Trimix is way too expensive, unless you're welding stainless.

[hankj]

I'm with Rocky.

When I took delivery of my first wire feeder (MM135) it came with a Smith regulator that was rated for argon mixes only. I ran that puppy for a very long time on straight CO² with wonderfull results.

In fact, I recommend CO² as the shielding gas of choice for all of the 120V wire feeders.

Hank

[Tinymx]

In fact, I recommend CO² as the shielding gas of choice for all of the 120V wire feeders.

Hank

What is your reasoning behind this? I was under the assumption that C25 gives better and cleaner welds. I know there is a small differance in price, but this is only a few bucks at my LWS. I just sold my SP135+ and bought a MM211. Would CO2 be a better choice?

[ace4059]

What is your reasoning behind this? I was under the assumption that C25 gives better and cleaner welds. I know there is a small differance in price, but this is only a few bucks at my LWS. I just sold my SP135+ and bought a MM211. Would CO2 be a better choice?

I am not sure of Hank's recommendation of Co2 on the 115v Mig welders.

However I would not recommend it on the 115V welder. It is fine for 230v welders. Yes c-25 does give better looking beads and they are cleaner.
The reason most people recommend 100% co2 is because it gives better penetration. But what they sometimes forget, is the fact that co2 has to be ran approximately 2 volts higher than c25. So the need for high volts when ran with co2 cancels out the better penetration. the smaller 115v welders are "hurting" for all the power they can get as it is. I really couldn't tell much difference on the penetration of co2 and c25 on the 115v welders.
If you are wanting the best penetration possible with a 115v welder, I recommend shelf shielded flux core wire.

I think c25 would be the best choice on just about all welders. The only one that excels on co2 is the Miller Passport.
A plus for co2 is the cheap cost.

-Ryan

[hankj]

CO² works really well on mild steel, period! The lower available voltages on the 120V MIG's present a moot point, since these machines are only capable of single pass welds on .125" and thinner mild steel. When operated within their specified limits, 120V MIG's run nicely using CO².

CO² is also a decent gas when run on the 240V MIG's. C-25 doesn't really make the difference in weld appearance. The operator does! Wetout may be a little better on the 240V rigs wirh C-25, as most of the 250-amp class machines are designed to run on it, but I've produced some really nice welds with a Millermatic 210 running CO² on the higher voltage taps.

Probably the better choice would be C-25, but for the money, CO² is fine.

Hank

[FWI]

Get a bottle of C02 or 75/25 the gauge will work fine you'll be glad you did.

[Discoman]

Get a bottle of C02 or 75/25 the gauge will work fine you'll be glad you did.

okay, thanks

[Rocky D]

You will need an adapter to run CO2.

[yorkiepap]

Hey Discoman,
You can use 100% Argon with MIG if you are using silicone-bronze wire only. I have C10, C25, & C2(98AR/2CO2) depending on application. For general use, C25 will fit most of your needs & will produce excellent results, especially for any sheetmetal applications.

Denny

[Steve from Ohio]

can I use just pure argon for mig?
i got a linde welder mig setup for really cheap, it included a regulator that is for argon only.
is pure Ar fine or should i go with a Ar/CO2 mix or even trimix?

Pure argon is fine if you are migging aluminum. Or for a tig welder.

I did find this:

The low ionization potential of argon also has some disadvantages when used as the only shielding gas in welding steel plate. The lower ionization potential reduces the arc voltage, creating lower power in the arc and therefore lower joint penetration, undercutting, and poor bead contour.
The combination of lower penetration and less spatter makes the use of straight argon desirable only when welding sheet metal, where excessive melt through and surface appearance are major concerns.

[aametalmaster]

Here is what happened to me last week. My 75/25 was empty so i had been using Co2 for most of the summer. I did some test beads on some galv sheetmetal with sil bronze and argon. Thats another story.
Anyway a guy stops over and wants a chrome pipe welded on his JD garden tractor. So i swap out the wire to my 70-S6 and forgot all about the gas. Yup the argon was still there. I welded up the pipe and told the kid it sure sounded like a lot of argon in that new bottle i just had filled. Refering to the bottle of 75/25 i just got a few days before. Then it hit me that i never changed bottles and i was still on argon. The weld was perfect looked like a fixture weld. But i would get a bottle of Co2 if it was me...Bob

[PaulChristenson]

http://www.mig-welding.co.uk/welding-gas.htm

[PaulChristenson]

A comparison between CO2, Argon/CO2 mix, Argoshield Light and pure Argon to find out which is the best on mild steel.
http://www.mig-welding.co.uk/welding-gas.htm