Identifying argon?

Well, you may be able to tell if it's CO2 that way; CO2 is soluble in water and will produce a mild acid which you could check for with pH indicator strips. Argon is inert so very difficult to test other than by an electrical discharge at reduced pressure where it has a lilac glow. Martin

Couldn't you flow the CO2 through a hose into a glass of water and then, shake the water to see if it fizzes or, taste it to detect the carbonation or some such?

I think this is the way carbonated water is made.

j/b

You can test for the presence of CO2 by bubbling the test gass through lime water see *

Does the nose detect very concentrated CO2? What's that "stinging" sensation if you make gas from drinking carbonated drinks hiss through your nose?

"jusme" wrote: Couldn't you flow the CO2 through a hose into a glass of water and then,

^^^^^^^^^^^^^^^^^ Carbonated water is made by allowing pressurized CO2 to dissolve in in water. That is why it fizzes when the pressure is removed.

If your cylinder contains CO2, it is most likely partially full of liquid. You should be able to tell this by laying it on its side and trying to balance it on a piece of wood or pipe. If it contains liquid it will be extremely difficult or impossible to balance, because the liquid will always go to the low side and cause it to tip.

How would CO2 get into an argon cylinder? Are the threads the same?

Yes

You are right. I looked at mine and have an adapter so I can switch the regulator between CO2/Ar/75-25.

Tom

I went and picked up a mixed gas cylinder to trade out for my MIG unit. Didn't pay any attention to it until I started to weld. What a crappy weld! I checked everything, and came to find out that they had given me a tank of argon. The weld was porous as a sponge, and looked like a weld done with no shielding gas. Did you try welding with the argon at all on MIG? I would be surprised if you got any sort of a passable weld.

I do know there are gas sniffers, and gas chromatographs that will tell you about all sorts of different things, but they cost thousands of dollars, some of them.

Steve

As an afterthought, argon and CO2 have distinctively different regulators. It is impossible to get them mixed up.

Steve

Huh? CO2 has a flat mating surface, and argon has a tapered seat.

Steve

I like the gas in water - giving an acid version - might have a flower or a ph strip that can ID a change. You want to be able to see the change not a specific number.

YouTube - CO2 Behaves as an Acid

I think it would be easier to go to the pool/spa place and get some ph strips or a ph test kit.

Then use water, test the ph. Add gas by bubbling in the bottom and test. If it turns acidic then CO2. If not changing at all - Argon (Noble gas).

Martin

Mart> --Speaking of gasses the last time Ernie came a-calling he pointed

Tell that to the kid at the welding store. You know, the one with the Really Big Wrench.

Generally, too, CO2 regs are cheaper. They are smaller, and I have seen them for as little as $15. Flimsy things when put beside a big Victor. I have also seen them frozen solid as a popsicle under heavy use. Perhaps Ernie could kick in here and comment on a big Victor being used with the C02 adapter as to its low temperature capabilities. And also, the safety and effectiveness of a small cheap CO2 regulator used with the Argon adapter.

Steve

You can adapt some regulators between gasses and valve stems, but it doesn't work all directions. Argon flow meters will work for CO2, but not all CO2 flow meters will work for Argon.

The flow gauges made for multiple gasses, like the Smith Select-o-gas flow meters will pretty much work with any shielding gas.

A larger argon flow meter is less likely to freeze up if running a heavy flow of CO2, than a small one.

The tanks in question was an Aluminum gas bottle that Ed had gootten at his supplier. I have NEVER seen Argon in an aluminum cylinder, and the gas ran really dirty and bad.

i became evident that even though the tank had an inert gas fitting, somehow it had either straight CO2 or more likely a Argon/CO2 mix.

I knew to look for it because of the sheer number of c*ck ups I have seen teaching welding for the last 15 years.

A bad bottle of gas can be one of the most frustrating problems to diagnose if you assume that every gas bottle is perfect. Once you know it can be bad, it makes it easier to spot next time around.

Pure argon works for aluminum MIG, but on steel it doesn't have a high enough arc temperature to work so the welds are very cold and covered in soot.

Yes but pure Argon and Argon/CO2 have the same valve stem.

Just flow the gas into a glass of water and drop in a Mentos. If it is argon, nothing will happen, if CO2, it should bubble violently.

j/b

--LOL!! If it works it'll be an elegant, if messy proof!

Been watching Mythbusters, have ya?