Wotcher,
If one tries to fill an ArgoShield in a DIY style, you'll never achieve the 'full' pressure.
Consider, connect the full bottle (A) to the same size empty bottle (B), open the valve...both bottles will equalise to half the original pressure. If you repeat this cycle 5 times (using a, get it filled new 'full' bottle and the same original bottle B each time) the end pressure will be 96%. 10 cycles and you'll get 99.9%.
Thats a lot of effort.
If you need a full ArgoShield get it filled professionally
It is posible to fill a CO2 cylinder quite easy (I'd avoid the pub gas bottles, the CO2 may not be dry, wet gas = naff welds)
Your CO2 target bottle will have a stamped weight of maximum allowed CO2, remove the valve, drop in said weight of dry ice, replace valve, allow to equilibriate to room temperature.
Dry ice is solid CO2, try an internet search for ease of purchase, get the numbers and weights right.....its not a problem.
In true 'Brainiacs' style I deliberately overfilled one, the bottle-did-not-burst, there is an anti-bursting disc within the valve head, although when it cuts loose it sounds like a jet taking off
gluck
auf
