How long will 3.6 lbs of CO2 last?

[Moody_Copperpot]

Have a 20lb tank, which is awesome. I haven't filled in in over 2 years. The needle on the gauge just recently started dropping. It's now right at the top of the red zone. The tare weight is 25lbs, and when I weighed it the scale read 28.6 lbs. I know that when that needle starts to drop, it can go quickly, so I'm wondering if I need to refill ASAP or not.

 

[PGEduardo]

This is when spare 5lb tanks come in handy.

I'd recommend re-filling as soon as it's convenient. Even if you burn a few pounds, they're guaranteed to kick as soon as you have people over (ask me how I know.) Unless you're on an extremely tight budget, just do it.

OR - if you have nothing coming up, then take good notes and answer the question of how long it'll take to kick (depends on your specific setup I'd guess) yourself.

 

[Moody_Copperpot]

Haha yeah I've had them kick at those perfect moments, with a house full of people as well! I may just wait it out and see, I really don't have anything crazy coming up.

 

[E_Marquez]

Have a 20lb tank, which is awesome. I haven't filled in in over 2 years. The needle on the gauge just recently started dropping. It's now right at the top of the red zone. The tare weight is 25lbs, and when I weighed it the scale read 28.6 lbs. I know that when that needle starts to drop, it can go quickly, so I'm wondering if I need to refill ASAP or not.

The tank will have roughly the same tank pressure (at the same tank temp) with 1 OZ of liquid CO2, and 20 LB of liquid CO2... .. the gas pressure remains pretty much the same. So the high side "gauge" reads ok till that last bit of liquid CO2 is gone.... then you see a very rapid tank pressure.. more pronounced on small tanks (paintball though 5lb or so) Larger tanks you get a bit more reaction time.

Don't run the tank to zero pressure... many gas shops will charge extra to purge at that point .
Oh and if moisture enters the tank due to it being at zero pressure..... CO2 and water gets you Carbonic acid

 

[Moody_Copperpot]

The tank will have roughly the same tank pressure (at the same tank temp) with 1 OZ of liquid CO2, and 20 LB of liquid CO2... .. the gas pressure remains pretty much the same. So the high side "gauge" reads ok till that last bit of liquid CO2 is gone.... then you see a very rapid tank pressure.. more pronounced on small tanks (paintball though 5lb or so) Larger tanks you get a bit more reaction time. Don't run the tank to zero pressure... many gas shops will charge extra to purge at that point . Oh and if moisture enters the tank due to it being at zero pressure..... CO2 and water gets you Carbonic acid

Yikes, well I don't want that to happen. Hmmm well I may get this sucker filled up after all.