> >I was at my LFES (local fire extinguisher shop) this morning and the guy
> >wanted $26 to hydrotest and refill my small CO2 tank. He was talking about 5
> >lb tanks and 25 lb tanks and I really wasn't thinking that much about it. On
> >my way to work (I am a chemist) I started to wonder- 5lb what, 25 lb what-
> >off course it hit me, CO2. So I started to wonder. I have access to vast
> >quantities of small pellet food grade dry ice. Could I remove the valve in
> >my tank and put it on a scale and add 5 lbs of dry ice then seal it back up?
> >Would this work or would I blow myself up? Anyone ever done this? Sounds
> >reasonable right, and It will save me 25 bucks.
> >
> >Thanks for your responses.
>
>
> Why not find a gas supplier that does a tank swap. Then you will just
> pay for the gas and they will certifiy the tank ;)
>
> Tom Veldhouse
>
Was gonna be my recommendation. Any welding supply outlet should have a supply of 5lb co2 cylinders already full. I work for Airgas, which is the largest supplier in the nation & with my employee discount I pay about $2.50 to fill my tank.