How empty is empty

[Jules The Great]

Not wanting to be rude and contradict what anyone else here as said but I use every last drop.

If you are welding to a code or spec then you obviously need to follow it.

For your home shop despite what anyone else here may assume if it is coming out under pressure which it does till it stops hissing than it is just as pure as it is at 2000psi. Obviously weld quality is a good tell

Now for my tig as the pressure gets lower I have to turn up the flow rate as the pressure getting to it is lower to a point. That may also work for your MIG gas but then you would have to remember to turn down the regulator again with the new bottle.

Also all gas places have to do a full purge of gas bottles before they refill them, and when they test them how ever often that is they send a camera down inside to make sure it is not rusted.

You are paying for the gas and they do not give you a refund if you return a bottle when it still has gas in it so might as well use it all

[Brian Ski]

Not wanting to be rude and contradict what anyone else here as said but I use every last drop.

For your home shop despite what anyone else here may assume if it is coming out under pressure which it does till it stops hissing than it is just as pure as it is at 2000psi. Obviously weld quality is a good tell

I would say I do the same... Run them until they are dry. As long as you are not leaving the valve open when you are done you won't get moisture in the tank.

Also a couple points... Argon, Oxygen, Co2 I run them dry. Acetylene I can run low and it will slowly build pressure back up and the acetylene escapes from the pores when I let it set. It can sure last a long time.

But what has brought up that I have never thought of is that a Argon Co2 mix should be rotated or stirred. I never have. I can see them separating over time. I have a tank that will last me a good year. So they have time to settle. Argon compresses into a high pressure (2000 psi tank pressure) and Co2 only compresses to about 200 psi and then turns into a liquid. I can see them separating. I still run them down. But good conversation.

[Winky]

Not wanting to be rude and contradict what anyone else here as said but I use every last drop.

If you are welding to a code or spec then you obviously need to follow it.

For your home shop despite what anyone else here may assume if it is coming out under pressure which it does till it stops hissing than it is just as pure as it is at 2000psi. Obviously weld quality is a good tell

Now for my tig as the pressure gets lower I have to turn up the flow rate as the pressure getting to it is lower to a point. That may also work for your MIG gas but then you would have to remember to turn down the regulator again with the new bottle.

Also all gas places have to do a full purge of gas bottles before they refill them, and when they test them how ever often that is they send a camera down inside to make sure it is not rusted.

You are paying for the gas and they do not give you a refund if you return a bottle when it still has gas in it so might as well use it all

Some good points ... I've always switched tanks when it still shows there's a tiny bit left so I would always be sure my welds were shielded ... perhaps I shouldn't be so wasteful.