CO2 VS Argon/CO2 mix while ferrous steel

[Alaska]

For years I used strictly 75/25% mix, always heard of bad welds from straight CO2 gas. When I finally went into the local university to get some credentials (helped with insurance and credentials for getting clients) I saw they only use CO2. The head guy said it was for budget reasons. Anyway passed my cert plates with straight CO2 and the welds look great. A little dark when finished as they lack the argon cleaning bennifits but nothing a little wire brush can't clean right up. So when my 150 mix bottle ran out last month, I went down to the local AirGas to get some more inert gas. I owned my bottle, and a refil once all the costs were paid was going to be $83. I then asked about a 35# bottle of straight CO2. a 35# bottle of straight CO2 has considerable more volume of actual usable gas than a 150 argon bottle. Anyway the straight CO2 was only $34. AirGas let me swap my argon bottle for a CO2 one, and I was out the door. The only modification you need to do to your Mig is to change the regulator out from an argon one to a CO2 one as the fittings are not the same. They do make an adapter that will allow you to use your argon regulator which I bought since it was only $15. I have since built an 8x12 trailer, and some other small projects using straight CO2 and it works great. My only problem is when hitting it hard my argon regulator gets cold and has stuck once. I am told a straight CO2 regulator will not do this. I have one on order from Ebay - costed me about $50 deliverd. So if I had to do it over again I would have just bought a CO2 regulator up front to save some cash in the long run.

My advise is give it a try for yourself. It cut my gas costs by over half and that means more money in my pocket. My welds to wet in fine and look iditentical to the ones I made with the mix in the past. I will post some picts of the welds on the trailer tomorrow. Heck, I may even weld up a demo plate as I have some scrap lying about.

I hope this was helpful. Wish someone would have given me the straight along time ago on gas as I would have saved a lot of money over the years.

[Scotty1]

For years I used strictly 75/25% mix, always heard of bad welds from straight CO2 gas. When I finally went into the local university to get some credentials (helped with insurance and credentials for getting clients) I saw they only use CO2. The head guy said it was for budget reasons. Anyway passed my cert plates with straight CO2 and the welds look great. A little dark when finished as they lack the argon cleaning bennifits but nothing a little wire brush can't clean right up. So when my 150 mix bottle ran out last month, I went down to the local AirGas to get some more inert gas. I owned my bottle, and a refil once all the costs were paid was going to be $83. I then asked about a 35# bottle of straight CO2. a 35# bottle of straight CO2 has considerable more volume of actual usable gas than a 150 argon bottle. Anyway the straight CO2 was only $34. AirGas let me swap my argon bottle for a CO2 one, and I was out the door. The only modification you need to do to your Mig is to change the regulator out from an argon one to a CO2 one as the fittings are not the same. They do make an adapter that will allow you to use your argon regulator which I bought since it was only $15. I have since built an 8x12 trailer, and some other small projects using straight CO2 and it works great. My only problem is when hitting it hard my argon regulator gets cold and has stuck once. I am told a straight CO2 regulator will not do this. I have one on order from Ebay - costed me about $50 deliverd. So if I had to do it over again I would have just bought a CO2 regulator up front to save some cash in the long run.

My advise is give it a try for yourself. It cut my gas costs by over half and that means more money in my pocket. My welds to wet in fine and look iditentical to the ones I made with the mix in the past. I will post some picts of the welds on the trailer tomorrow. Heck, I may even weld up a demo plate as I have some scrap lying about.

I hope this was helpful. Wish someone would have given me the straight along time ago on gas as I would have saved a lot of money over the years.

Have been Mig Welding/Mild Steel Plate/Stainless Steel for over 35years With Sraight CO2.
No Probs.

[DaveO]

I understood straight CO2 would work well on heavier plate, and that Ar/CO2 was required for thinner lighter materials. If you get a chance to post demo pics of CO2 on your scrap plate, would you mind running a test on lighter material too?

[cbmkr]

Straight Co2, Mix 92/8,Stargon ( 98% Ar, 8% Co2, 2% O2 ) or 75/25 what i currently use at home will work.We started with straight C02 ( Leaves small shinny droplets on your weld that will clean off) at our manufacturing plant in the early 1970's and worked our way up to the Stargon product thru the late 80's,it worked well for our high speed spray arc W/.045 solid wire and 1/16" & 5/64" flux core machines on different applications it also minimized the gray brown smoke film known as tenacious soil that collected around the weld edges.This helped in prep work before painting as cleanup was easier.The Stargon mix product also produced less smoke in the plant.

[everlastsupport]

We went with Stargon a couple years ago. Not sure if a PraxAir thing or not, but that is where we get it normally and WSI for the 75/25 (they do not have it and I have one rental from them). We prefer the stargon as well. I think it was in the mid $50 range last bottle, a 250. So price is not too bad.

$83 for a 75/25 150 would tick me off big time.

[Alaska]

I found these two welds lying about in the shop, one is a 3/8" plate 2g and the other is an 11 or 12ga 3f. Hope the 11 or 12ga is thin enough for you DaveO, I do not do many sheetmetal projects.



Just remember to clen the welds with a wire brush - I use a 4.5" grinder with wire wheel installed and it cleans right up in seconds.

Hope this is helpful.

[Alaska]

Welcome to my world. Shiping cost is out of control up here as well as everything else. At least diesel is back under 4 bucks a gallon - for now at least!

[Rambozo]

Welcome to my world. Shiping cost is out of control up here as well as everything else. At least diesel is back under 4 bucks a gallon - for now at least!

Still sounds cheap compared to the guy in Hawaii.

[ShaneJackson]

How about $80 for a 125.... I called around today and can get a 330 filled for $75 at a supplier just south of me..... Add in the $65 a year for rent and it is still cheaper even if I don't get it filled but once a year....

[everlastsupport]

Welcome to my world. Shiping cost is out of control up here as well as everything else. At least diesel is back under 4 bucks a gallon - for now at least!

Yea, like I said I would be ticked on the mixed gas.

Now if I lived where the pipeline was and paid more for diesel than the East coast (at $4 a gallon here for some time where I am), I would be even more ticked off. You live in the state that pumps it right??? Maybe Sara Paylan would have been a mistake.

The straight CO2 welds looks fine. I have a tank going in Wed, maybe I will swap it and try it. It's a spare tank someone gave me and the Prax guy I use is on vacation until Wed. If they will take the tank I'll probably do that.

[everlastsupport]

Still sounds cheap compared to the guy in Hawaii.

Forgot about him. That was beyond nuts.

$72 for a 330 is not a bad price at all compared to their prices.

[Rambozo]

Forgot about him. That was beyond nuts.

$72 for a 330 is not a bad price at all compared to their prices.

As I recall it seemed like here you could just throw away the bottle and by a new one each time and still pay less than he did.

The cost of paradise.

[Rodsmachineshop]

hey i am getting a bottle of co2 that way i can make my own soda plus mig weld

[zoama]

How about $80 for a 125.... I called around today and can get a 330 filled for $75 at a supplier just south of me..... Add in the $65 a year for rent and it is still cheaper even if I don't get it filled but once a year....

If you don't mind driving 35 miles, try weldor's supply house. I paid $295 for a filled 390 cu ft of 75/25 with a 99 year lease and $60 for refills. They even throw in free renewal when the lease is up. http://maps.google.com/maps?hl=en&su...d=0CI0BEPwSMAA

[Rambozo]

hey i am getting a bottle of co2 that way i can make my own soda plus mig weld

My favorite is to make carbonated grapes.

[Rambozo]

...They even throw in free renewal when the lease is up.

I'm sure your grandkids will appreciate that.

[everlastsupport]

My favorite is to make carbonated grapes.

I'm with you Ram.

Talking about CO2. Ironically I have an aluminum tank, looks like about an 80CF someone gave me thinking it was a welding tank. CO2 valve is non-standard far as gauges. It has a soda logo company on the side too.

Rod you want it? Pay shipping or take a vacation in SE Florida and it is yours. hahaha.. It is set for soda and I know you can adapt it for MIG too. Add a Y connector.

[everlastsupport]

I'm sure your grandkids will appreciate that.

Great grandkids will.

[ShaneJackson]

Great price if I needed mix, I need pure argon... but I will give them a call tomorrow and see what kind of deals they have. Looks like all the good deals are on Asheville hwy.

[performance]

A couple of things about CO2. I have used both extensively...so.
1) CO2 is NOT inert. It is an active or oxidizing gas. It does introduce impurities into the weld as it is superheated. The top of the weld isn't in the condition it is because it isn't cleaning...it is in the condition it is because it is oxidized by the C02. CO2 does better than nothing for sure, but it isn't ideal for a quality weld
2) Voltage required for the arc to bridge the gap using C02 is higher. This means you are naturally going to run hotter, and have a more violent AND unstable arc situation.
3) Clean up expense and time, if you are into that sort of thing (making a weld look clean and nice), can make up for the clean, pure look of the weld, because much higher rate of spatter also sticks harder when CO2 is used.
4) Regulators, even CO2 ones, will freeze. They make "heaters" for the regulators you can use.
5) Gas flow rate requirement for CO2 seems to be higher, so consumpution is higher.

As far as the price difference, I have kept up with my labor for both, and the specific blend I use, and for me it pays to use a higher amount of Argon, even though it is more expensive. I personally use an 18% CO2 content.