Can you tell how much CO2/Argon in bottle by weight?

[Mutt's37Buick]

I bought a used MIG welder over the weekend with a partially used CO2/Argon bottle.
The bottle is 3 ft tall, labeled AirGas and I believe is their 80 Cubic ft size. The bottle currently weighs 50 lbs.
1) Is there any way to determine how much gas is left in the bottle from the weight?
Thanks

 

[Bonehead]

Found this, I think it is right: Empty weight is shown below, however, some bottle weigh a little more, and some a little less.

300 132 lbs.
250 108 lbs.
200 106 lbs.
150 65 lbs.
125 64 lbs.
80 49 lbs.
60 26 lbs.
40 23.5 lbs.
20 10.5 lbs.

The empty weight should be stamped into the bottle.

 

[Willowbilly3]

If you just install the regulator, the gauge should give you a pretty good idea what's left in the bottle.
I hope you checked with the local supplier of that brand to see if the bottle could be sold, most of them are leased. I've seen a lot of guys buy bottles only to find out they had to surrender them when they went to get them filled.

 

[Bonehead]

If you just install the regulator, the gauge should give you a pretty good idea what's left in the bottle.
I hope you checked with the local supplier of that brand to see if the bottle could be sold, most of them are leased. I've seen a lot of guys buy bottles only to find out they had to surrender them when they went to get them filled.

Very true, however, it seems to vary state to state, and supplier, by supplier. I own all my bottles now. But I have no papers on any of them. I moved from Oklahoma in the 80's and turned in my leased bottles before I moved. I owned two bottles, and it took me a while to figure out the system here in western Colorado. Now I own about a dozen bottles, and the welding supply company stops in here and trades my empties for full ones. They don't keep up with the serial numbers. A totally different system from Oklahoma.

 

[Mutt's37Buick]

Thanks for all your help.
I did check that I could refill the bottle and it depends on size. Larger bottles at the local gas distributors are leased, but this one can be purchased and they said I could refill.
1) General air was a lot cheaper to fill than Airgas when I called ($.55 cu/ft vs $.88. Does anyone know if these costs are typical?
Thanks

 

[anvil]

Back in Washington you can lease or buy and they can tell by the collar around the top. If its stamped with the stores name or blank. Years ago I had a shop switch them on me and the next time I came in they took my bottles and I was like hay WTF. Now that I am here in Helena Montana the stores only rent bottles and want to ship out mine to get refilled and give them a couple weeks to do that.

 

[klink]

If you just install the regulator, the gauge should give you a pretty good idea what's left in the bottle.
I hope you checked with the local supplier of that brand to see if the bottle could be sold, most of them are leased. I've seen a lot of guys buy bottles only to find out they had to surrender them when they went to get them filled.

The only thing that matters is the inspection date. If your not going through the gas very fast, then use a place that exchanges full tanks for empty tanks. Then all you need to do is pay attention to the date. The Napa store that I use will even take them if the inspection is past due because they deal with a supplier that also inspects tanks.

 

[hoggyrubber]

i have had real good luck getting them traded out. in fact one place in town would let me trade down or up sizes or 2 bottles for one bigger. they had a list of what bottle cost and would give that much credit. i always buy bottles if i see them for cheap at a auction or sale. yoes if it says rental i leave it alone. i have over 20 between o2, co2, argon, and ac so i have all i need now.