Filling a 4oz co2 tank from a 24oz co2 tank- any hints?

[automikey]

I have a photo of a simple way to fill my 4 oz tanks. It's basically a SS hose with an on/off on each end. Is this correct?: I fill my 24 oz, connect the lines, invert the 24 oz to get liquid co2, place the 4 oz on a digital scale. Let some co2 into the 4 oz, close it up, bleed the 4 oz to cool it down, then refill the same way, up to 4 oz in weight.

Any safety comments, etc?

Also, is the hpa/scuba fill also this easy? I just got certified, so I'll have a scuba tank soon anyway.

[Jaan]

Why not just get a 20 lbs tank, and fill your tanks from that?

[automikey]

Where does one usually get them? What adapter do you need to fill the tanks? Thanks.

[wanna-b-ballin']

i tried that. make sure that you unscrew both on/off asa's before you unscrew the tanks. i forgot to do that, and very cold air went all over the place and froze my hand pretty good.

[Jaan]

Where does one usually get them? What adapter do you need to fill the tanks? Thanks.A place like BOC gasses would have 20 lbs tanks (or larger). Anyplace that deals with gasses in bulk and since you live in upstate NY you probably know where to get your propane tanks filled ... many of those places will fill CO2 as well. You need a 20 lbs syphon tank since it has to draw liquid CO2 from the bottom. You can usually buy a "fill station" from a paintball store or you can put one together from plumbing parts. This is one I made years ago from stuff that I had around:

http://www.jayloo.com/files/pics/30000/FillStation.jpg (http://www.jayloo.com/files/pics/30000/FillStation.jpg)