[Khandurian]

Ok, ive searched and searched for this one.

I went to go get my new 5lb co2 tank filled. The guy at the shop (local welding shop) asked if I wanted 5% or 8%?

Uh, theres a percentage? I told him 5% as that was closer in price that everyone mentions as to what the average cost would be to fill up a 5lb tank.

So, i'm curious. Is the 8% more pure? Is it designed more for welding? :help:

 

[epicfish]

Wha...? I've never heard of percentages with regards to CO2.

Maybe he meant impurities, in which case, 5% is better than 8%, obviously. Which one was more expensive? 5% or 8%?

 

[Blacksunshine]

I get my fills from a local welding shop. I say "Gimme CO2." They swap the tank. No questions about what grade I need.
Calling around to all these welding shops and the local brewers while I was searching for a fill spot yeilded that everyone gets from the same place.

Brewers,welders,fire extingushers,soda vendors, etc etc etc all use the same grade CO2 wether they know it or not.

 

[cbennett]

same here, never heard of a grade no matter which place I go to.

 

[Rex Grigg]

That's really strange. Are you sure you got CO2? Normally even the lowest grade of CO2 one sees is 99.9% pure. That's what is used for welding, beer and soda, aquariums and fire extinguishers.

I would really like to know what they mean by 5% and 8%.

 

[Khandurian]

According to the receipt, it says Filled 5# 5% carbon dioxide.

The pressure gauge reads 1000psi. I have no clue. This is all new to me!

 

[Rex Grigg]

I would call. That's really strange. I've never seen that in the past nor heard of it. Call and make sure what you got is 100% CO2.

 

[snafu]

it kinda sounds like 5% CO2 with balance air or nitrogen?

 

[Khandurian]

Well, I guess I wont be going back there. It's what snafu said, 5% co2 with a balance of air.

It was explained to me after I called, they fill 5% of the bottle with 100% co2 and then pressurize with air.

I kinda feel like I got ripped? Thoughts?

 

[Rex Grigg]

You got totally ripped off. You went in there and asked them to fill your CO2 cylinder. You would expect that your CO2 cylinder would be filled with CO2. I would take it back. Get the manager by the stacking swivel (throat for you civilian types) and explain this to them. Then once you get your CO2 cylinder filled with CO2 or your money back I would leave never to return.

 

[Khandurian]

In my younger years, I would do such a thing. However, since it was not a great deal of money, (13$) I have learned to chalk it up to bad experience.

I have also learned that in my community all I have to do is tell the right people and they wont be getting any more business any time soon.

 

[snafu]

its probably more of a misunderstanding than someone trying to rip you off. industrial gas supply places sell all different mixtures of gas for different applications. i agree with rex... i would explain it to the store manager that you were looking for 100% CO2 gas. the worst that could happen is he says 'sorry you're outta luck'.
-snafu

 

[eklikewhoa]

Maybe they mixed it there? 5% C and the rest O2?

 

[Rex Grigg]

Maybe they mixed it there? 5% C and the rest O2?

Haven't taken a lot of chemistry?

What you suggest is impossible. There is no pure carbon gas outside of very limited laboratory conditions.

 

[dogg76]

It's probably a mix of Co2 and argon...Thats what we use at work but it's #7 25% Co2 and 75% Argon....I wouldn't use it in my tank.....

 

[rnakas]

It's probably mixed with argon for welding?

 

[dogg76]

It's probably mixed with argon for welding?

Correct...

 

[Blacksunshine]

Correct...

Do they pre mix them? I thought that you would have seperate tanks and mix them at the point of combustion. I'm not a welder by any means but that was how I understood for that type of welding to be done.
Hence the need for 2 bottles.

 

[dogg76]

Yes, it's premixed in one bottle, I weld at work and we use #7 gas, which is 25% Co2 and 75% argon. Point of combustion? You must be thinking of a cutting torch, which uses 2 separate tanks....

 

[Blacksunshine]

Yes, it's premixed in one bottle, I weld at work and we use #7 gas, which is 25% Co2 and 75% argon. Point of combustion? You must be thinking of a cutting torch, which uses 2 separate tanks....

humm. maybe. yeh probably what I was thinkin.