[adrynalinjunkie]

My Argon is down to about 200 psi and it seems like when I was welding aluminum last night with the same 20 CFH that it didn't have enough gas.
Do you guys keep turning up the flowmeter or at what point do you go get the bottle filled?

[Otto Nobedder]

I rarely use a bottle below 100 psi on a reliable gauge, but I don't buy my gas.

If you have a dial-type flowmeter, I'd change at 200, easily, as input pressure to the second stage has a significant effect. With a float-ball flowmeter, you'll get reliable readings down to the set pressure of the first-stage regulator (usually 60-75psi)

Steve S

[Bill Beauregard]

I use it till it won't work. Then after taking off the regulator there is still enough pressure in the tank, it's hard to stop it with the palm of my hand. I was blaming the regulator.

[Rick_H]

Like Steve I use it till I'm around 100-80 lbs then I change bottles or I go have it filled even at home.

[Braehill]

Wow, you guys are the "the glass is half empty" crowd. I change mine at 2640 psi, but I'm filling them.

No, I change them when they get below my regulator pressure, which I have set at 50#. My 80cf Mig cylinder gets used down to the same, but I get it filled and not exchanged, so I pull a vacuum on it to remove any moisture before I take it to the cylinder fill yard.

Len

[weldin mike 27]

I find it varies according to the machine. Some will allow efficient use to almost nothing, but some mess up quicker. Also ss (309 anyway) will allow lower than mild steel. It doesn't get porosity (probably not the best practice for critical welding)

[AKweldshop]

Change it right before you get poor welding results.

[wheresmejumper]

If working on mild/carbon steel you will hear a sizzle at the first sign of impure shielding,even before seeing surface porosity. Its easy to react immediately.
Working with stainless is totally different,only when you stop welding and inspect the bead will you see the tell tale black finish that indicates all is not well

[Graveyard]

I usually let mine get down to below 100 as well before i take it in for an exchange.

[TwentyFourSeven]

I use mine until it starts burning my aluminum. Well below 10 psi.

[rick9345]

I watch the bouncing ball.
When tungsten doen't stay clean, and ball has to be rasied at end of each weld time for a change.
About twice, hate redoing welds.