Interesting Uses for Old CO2 Bottles???

[Richard D]

I have an old CO2 bottle, don't know the size, about 10" dia x 5' tall. I was planning to put an argon valve on it like I have before with other bottles, but the guy who did it last time said old CO2s rust inside and can't be converted into other type bottles. Anything cool I can make out of it? I have seen bells, was wondering what else.

 

[rlitman]

Rust inside is a reason to fail the cylinder, not prevent you from switching it to argon.
But many CO2 cylinders are not rated for the higher pressure of argon service, so that could be it.

Yes, they make good bells.

 

[zkling]

I've made quite a few forges out of them. Those were mostly the smaller cylinders though.

 

[rsanter]

How about using it as a trade towards the one you want

Bob

 

[rbjenterprises]

I used smaller ones as a pressure tank for a onboard compressor on my truck. It fit next a frame rail.

 

[Clik]

I was planning to weld another port in one of mine, fill it with marbles to make a big water seperator out of it and pipe it in to my shop air supply. Media blasting requires really dry air.

 

[Blue XJ]

I have a regulator on my 20# tank. I use it to run air tools and fill up tires, quick jobs that I don't want to wait for my compressor to fill, or in the house where I don't want the noise. My 20# tank will air up all 4 of my 35" tires on my Jeep from 5 to 35 psi about 5 or 6 times. Costs about $20 to get a refilled exchange tank.

 

[j p smith]

I cut one for a friend to make a Mortar out of, when completed it will launch bowling balls. It is not finished yet, but I will post pictures when it is completed.

 

[kingston]

I cut one for a friend to make a Mortar out of, when completed it will launch bowling balls. It is not finished yet, but I will post pictures when it is completed.

F-yea!!!!

Please post video when completed!

 

[NUTTSGT]

My step-dad made a windchime out of one.

 

[Richard D]

Cannon, air tank, water separator, all would suit my needs.

The welding gas man said the same thing on the rust issue.

 

[Richard D]

I've made quite a few forges out of them. Those were mostly the smaller cylinders though.

How do you do that? Pictures?

 

[LifeLongWNYer]

Someone should explain how the CO2 makes a bottle rust, I don't get it. The gas is dry when the tank is filled, where does the moisture come from? The gas fill should be 100% CO2, and if it is, that means zero % water.

My guess, which might be wrong, is that as long as the tank passes the hydro test, it should be good to use.




.

 

[rlitman]

Someone should explain how the CO2 makes a bottle rust, I don't get it. The gas is dry when the tank is filled, where does the moisture come from? The gas fill should be 100% CO2, and if it is, that means zero % water.

My guess, which might be wrong, is that as long as the tank passes the hydro test, it should be good to use.




.

More importantly than no water, zero oxygen.

 

[FlyingLow]

Someone should explain how the CO2 makes a bottle rust, I don't get it. The gas is dry when the tank is filled, where does the moisture come from? The gas fill should be 100% CO2, and if it is, that means zero % water.

My guess, which might be wrong, is that as long as the tank passes the hydro test, it should be good to use.
.

More importantly than no water, zero oxygen.

This usually accumulates when the tank sits empty. The hydro test is more than just pump it up and see if it blows. I have heard that the old school tests included hitting it with a hammer and listen to the ring it has, if there is imperfections it will have a different ring, like a tuning fork. In todays world it would take nothing to run a borescope in to have a look.

 

[Zrexxer]

This usually accumulates when the tank sits empty.

Water cannot "accumulate" inside a sealed pressurized cylinder, that has no water in it to begin with. Or, if you've figured out a way to synthesize water in the absence of hydrogen, you're about to be the richest person in the history of man.

All four of my CO2 cylinders are aluminum though, so I'd be damn surprised to find any rust inside.

 

[FlyingLow]

Water cannot "accumulate" inside a sealed pressurized cylinder, that has no water in it to begin with. Or, if you've figured out a way to synthesize water in the absence of hydrogen, you're about to be the richest person in the history of man.

All four of my CO2 cylinders are aluminum though, so I'd be damn surprised to find any rust inside.

once a cylinder is empty and its allowed to equalize with atmospheric pressure moisture can get in. I'm not talking accumulation of water, just a small amount of moisture. Especially if you are using it for pressurizing kegs of beer or pop, air is somewhat free to come and go if the CO2 runs out and it is left for a period of time. Not to mention, the hydrostatic testing includes water, not sure how it is completely removed after (maybe heat?). CO2 is acidic, carbon acid, under certain circumstances if you want to get technical. I see many ways for moisture to accumulate and that is why they test the bottles, for weaknesses that can not be seen from the outside.

 

[jeep_boy02]

X2^ we leave the empties valves open so everyone can easily tell if it's full or empty at my bar. So that would be an easy way for moisture to sneak in.

 

[Zrexxer]

Can't speak for what restaurants do, but in the welding industries, draining a cylinder 100% is extremely bad practice for exactly that reason. Cylinders are always exchanged when there's still some residual pressure in them.

 

[cjn1014]

CO2 cylinders are also susceptible to water due to the nature of their service. Frequently, restaurants will allow CO2 cylinders to run empty while hooked up to their soda dispenser setups (including the bulk syrup-domestic water mixers). If the backfill preventers are not working on the water side, you'll end up with water in the cylinder. CO2 + water equals carbonic acid, which pits steel. We would tip every CO2 cylinder prior to filling, because of the bad PM on back flow preventers in restaurant/bar mixers.

The scale rust isn't the issue (it can be cleaned during hydrotesting with a internal brush), the issue is pitting which decreases nominal wall thickness.

The real reason for not being able to convert is that the OP's cylinder is a 50# CO2, probably rated for 1800 PSI working pressure. Argon/typical shielding gases is a 2015 or 2400 PSI service. CO2 is found in shielding gases like C25, FWIW.

 

[Farmall450]

Can't speak for what restaurants do, but in the welding industries, draining a cylinder 100% is extremely bad practice for exactly that reason. Cylinders are always exchanged when there's still some residual pressure in them.

+1 you don't just leave them open when you think they're empty either.

 

[maxmojo]

bollards

 

[Richard D]

This cylinder was used for beer years ago. Still curious about the forge...