Hi all - I use CO2 for MIG welding steel. I am wondering what my options are for CO2 ( carbon dioxide ) gas cylinder / bottle ? Unlike high-pressure mixed gas (Ar/CO2), there appear to be several sources of CO2 - some quite inexpensive. Searches on the Weldingweb, revealed a hit/miss splatter of conventional looking high-pressure cylinders, 20 lb cylinders (application unknown), beer/soft drink cylinders, fire extinguishers, paint-ball cylinders, etc. It would be great if all this information was located in ONE THREAD!
So, can you enlighten me - and us all?
What CO2 cylinder / bottle / tank do you use, where do you get it and what does it cost for the cylinder and how much for the gas fills?
*** The Cheaper - the Better! ***

Rick V

I run C02 on my Lincoln SP175 plus. I have a 20 pound tank on my welding cart. C02 weighs about .1234 lbs. per cf. Therefore, at approximately 8.1 cf per pound, it is equivalent to a 162 cf gas cylinder. It's about $25 exchange plus HazMat fees and tax for a refill. It seems to run quite a while if you don't run excessive rates on the regulator and I like the way C02 welds on steel. At 20 or 15 cfm, it will run about 8 or 10 hours, respectively. That's a lot of welding for me.

I do my exchanges at my local welding gas store. It's possible to find cheaper sources if you know someone in the beverage or fire extinguisher business but I wouldn't bother. I just have a standard exchange bottle and go to the store when I need another tank. Also, that way, I can be certain of the quality and my regulator fits nicely..

.

 

Gnm109 - thanks for the response (I was starting to get lonely.)

On the 20 lb tank:
OK on the ~$25 to exchange - that sound cheap... but a few questions:

1 - 'exchange': Is this (a) a fill while you wait - or as it sounds, (b) you drop off your MT tank and leave with a full one?

2 - Did you have to purchase this tank initially? If so, how much was that?

3 - What is a HazMat fee.... and how much is that?

Rick V

 

If you are going to weld with the CO2, you should get your gas from a welding supply, instead of getting paintball, beer/soda cylinders, or fire-extinguishers. When you weld, you need high quality welding gas to avoid moisture and other impurities that may be in the gas meant for uses other than welding.

 

I too, use CO2. Where I got the bottle... if I told ya, I'd have to kill ya. Just joking, Had it for years, can't remember where. I get it exchanged at the local welding supply house. If memory serves, it's like 20 bucks plus taxes, fees, title,... on a 20lb tank. ( though I could probably borrow a CO2 tank from work's soda fountain, regulator is the same ).

 

Gnm109 - thanks for the response (I was starting to get lonely.)

On the 20 lb tank:
OK on the ~$25 to exchange - that sound cheap... but a few questions:

1 - 'exchange': Is this (a) a fill while you wait - or as it sounds, (b) you drop off your MT tank and leave with a full one?

2 - Did you have to purchase this tank initially? If so, how much was that?

3 - What is a HazMat fee.... and how much is that?

Rick V

I just go to AirGas. I looked into my welding file and found the original invlice.I initially paid for "a" CO2 tank. They charged me $150.40 for the initial tank plus $11.00 (about half price) for the first tank. After that, they charge me $23.42 for an exchange CO2 tank plus a $1.00 "Haz Mat" fee. The Haz Mat fees are for programs that have to do with education and control of hazardous materials. I think it may be federal, although California likely gets some of it, too. Probably you will pay that where you are as well.

I couldn't tell you whether I own the tank or am leasing it. Actually, it makes ilttle difference since I am only exchanging tanks. Most welding gas suppliers don't fill your tank while you wait, anyway. For obvious reasons, the filling plants are usually remote from civilized areas. Ha.

The initial tank cost would have been almost the same for a 160 cf argon/C02.Thereafter, for refills on argon/CO2 AirGas charges $60.00 for a 160cf exchange refill. Then you add tax , haz mat and so on and you are spending a great deal more.

Since I'm not building bridges or trying to please any customers (or nasty bosses for that matter) CO2 does just fine for me. It makes some nice welds, too.

I also have two 160cf argon tanks for my TIG welder. I run one of those down and then change to my spare and then I go and get another one when I have time. If and when I want to try MIG on aluminum or Stainless, I can use one of those tanks for shielding gas.

 

Gnm109 - thanks for the clarification. Hey the ~$25 per fill sounds great... but the $150 initial buy-in looks pretty steep.
Geez, it's like the old joke... "Well I gotta Good News and I gotta Bad News!"

Your dual option: a choice between either 100% Argon or 100% CO2 sounds a good way to proceed considering your equipment.

So, I wonder where Slamdvw got his tank / bottle / cylinder ??? Sounds like once you have an acceptable container, you can operate very economically on CO2 for less than 1/2 the price of mixed Ar/CO2.

Weldrwomn has a concern about CO2 gas quality. I wonder though. I mean we are talking about welding - blowing gas (with air swirling around) over an arc and hot metal. We don't need medical quality gas and further we are not dissolving it a beverage (beer / soft-drink) that we are going to ingest. While I could see the need for dry gas, I doubt that welding CO2 gas is the purest from of CO2 available. Heck, they dope up mixtures of Argon, helium, oxygen, CO2 - and charge you more; I doubt that trace amounts of other gas will have a great affect - especially on MY WELDS!! Ha, Ha!

You guys/girls response been useful... still waiting to hear about other possible sources for CO2.

Rick V

 

Gnm109 - thanks for the clarification. Hey the ~$25 per fill sounds great... but the $150 initial buy-in looks pretty steep.
Geez, it's like the old joke... "Well I gotta Good News and I gotta Bad News!"

Your dual option: a choice between either 100% Argon or 100% CO2 sounds a good way to proceed considering your equipment.

So, I wonder where Slamdvw got his tank / bottle / cylinder ??? Sounds like once you have an acceptable container, you can operate very economically on CO2 for less than 1/2 the price of mixed Ar/CO2.

Weldrwomn has a concern about CO2 gas quality. I wonder though. I mean we are talking about welding - blowing gas (with air swirling around) over an arc and hot metal. We don't need medical quality gas and further we are not dissolving it a beverage (beer / soft-drink) that we are going to ingest. While I could see the need for dry gas, I doubt that welding CO2 gas is the purest from of CO2 available. Heck, they dope up mixtures of Argon, helium, oxygen, CO2 - and charge you more; I doubt that trace amounts of other gas will have a great affect - especially on MY WELDS!! Ha, Ha!

You guys/girls response been useful... still waiting to hear about other possible sources for CO2.

Rick V

Gas quality is certainly a concern. I would want to know that there is no excess moisture or some traces of other gases. At least you are fairly well sure of what you are getting when you go to a reputable welding gas company.

As far as the initial cost, that's about what you'll pay most anywhere but it's only a one-time cost. As I said, I don't care whether it's a lease or a purchase. If I were to sell the welder, which is extremely unlikely, the new owner gets the tanks and he or she can go to Air Gas and exchange it. I know for a fact that they never even look at the tank serial uumbers so long as it looks like one of their tanks. Although I got most of my tanks from them, I have yet to be challenged.

There is also the issue of safety. when I am working near a tank with 800 psi of liquid CO2 or 2,000 psi of gaseous argon, I want to know that the cylinder has been hydro-tested sometime this century and that there is only a very small chance that if I handle the bottles correctly with safety caps and chains when moving or using them, I will have a problem.

Good luck.

 

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92821

 

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92821

The Harbor Freight tank is $139.99 for a 70.8 cf tank. That's only about 8.7 lbs. of CO2. That would last you only 3.5 hours at 20cfm. That's no deal at all for a tank that none of the welding gas companies will refill. They won't touch a tank like that.

Its a much better deal to go with a welding gas company and pay the initial amount (around $150). then you get good reliable gas thereafter in a safe tank that's been inspected for only $23.50 for 20 lbs/162cf. That makes more sense to me.

My final 2 cents. :blob1:

 

Hi all,
I looked into CO2 and C25 (Argon 75% / CO2 25%) prices in Ottawa and present the welding and fire-fighting gases prices below.

[By the way, to convert the Canadian dollar to US$, multiple by 0.88, that is the Canadian dollar = 88 cents US. So, if it says $100, that's $88 to you Southern Boys]

BOC Prices Ottawa October 12, 2006
Cylinder.....Gas......Volume......Rental......Own.......Refill
K..............CO2......~50 lbs.....$95.75/yr...No.........$ 56.75
C..............CO2......~15 lbs.....$67.05/yr...No.........$ 32.25

T...............C25......~330 cf.....$95.75/yr...No.........$148.50
M..............C25......~120 cf.....$95.75/yr...No..........$ 64.75
C..............C25......,~ 55 cf......$95.75/yr...No.........$ 47.50
C..............C25.......~55 cf.......................$282.......$ 47.50

Air Liquide Prices Ottawa October 12, 2006
Cylinder.....Gas......Volume......Rental......Own.......Refill
?...............CO2......~64 lbs.....$72.00/yr...No.........$ 78.00
?...............CO2......~50 lbs.....$72.00/yr...No.........$ 58.82
?...............CO2......~20 lbs.....$57.95/yr...No.........$ 31.64
?...............C25......~290 ft3....$72.00/yr....No.........$148.62
?...............C25......~124 ft3....$72.00/yr....No.........$ 84.00
?...............C25......~ 40 ft3......................$185......$ 49.00

Davidson Fire Extinguisher - (Purchase only: used tank (hydro'ed) + new valve)
Cylinder.....Gas......Volume.............Rental......Own.......Refill
?...............CO2.....~ 5 lb (...40 cf)....No............$ 95....$16.00
?...............CO2.....~10 lbs (..80 cf)....No............$115....$16.50
?...............CO2.....~15 lbs (120 cf)....No............$130....$17.60
?...............CO2.....~20 lbs (160 cf)....No...........$155.....$21.00
Refills of your own tank are done while you wait.

So, what have we got so far?
Based on 120 cubic foot cylinders of C25 or 15 lbs of CO2 (1 lb CO2 = 8 cf), C25 costs 2 to 5 times as much as CO2 depending on the source of CO2.

1 From the Fire Fight Guy: CO2- a 20 lb tank holding 160 cubic feet cost $155 to purchase, $21 to fill (7.5 cf/$).
2 From the Welding Guy: CO2- a 20 lb tank holding 160 cubic feet is ~$60/yr rental cost, $31 to fill (5.2 cf/$).
OR
3 From the Welding Guy: CO2- a 50 lb tank holding 400 cubic feet is ~$72/yr rental cost, $60 to fill (6.6cf/$)
4 From the Welding Guy: CO2- a 64 lb tank holding 512 cubic feet is ~$72/yr rental cost, $78 to fill (6.6cf/$)

So, the best deal on volume of gas for the buck is #1: 7.5 cubic feet per dollar from the Fire Fight Guy.
Comparing the 160 cubic foot options, in 2.5 years of rental you could pay off the purchase price of the fire extinguisher tank.

Rick V

 

My local supplier is pretty good, just got my 380 tank for MIG filled for $38.

 

I am wondring if there may be other sources for CO2 gas cylinders / tanks / bottles - other than welding gas suppliers and fire extinguisher companies?
Any ideas?
Rick V