Hey there, just after some advice on the above topic. 
Just bought a new Mig and though I don't do much welding i'm gonna move from disposables to reffilable bottles.
Never used these before, and seems that a lot of people rent the bottles. However I've seen quite a few of these around second hand, both BOC style and pub gas style CO2 bottles.
Got a few Qs about these though:
Is there a reason why i should avoid buying a second hand bottle, over renting one?
Do bottles have to carry a certificate or anything in order to get them re-filled? if so what form does this come in? i.e markings/plate/paper certificate?
Also from what i can work out, argon is stored at higher preassure than co2 so if i buy an argon bottle i can then potentially use it for co2 or argon co2 mix. Is this correct.
Sorry for all the Qs, and thanks in advance for any help
Dan
				
			Just bought a new Mig and though I don't do much welding i'm gonna move from disposables to reffilable bottles.
Never used these before, and seems that a lot of people rent the bottles. However I've seen quite a few of these around second hand, both BOC style and pub gas style CO2 bottles.
Got a few Qs about these though:
Is there a reason why i should avoid buying a second hand bottle, over renting one?
Do bottles have to carry a certificate or anything in order to get them re-filled? if so what form does this come in? i.e markings/plate/paper certificate?
Also from what i can work out, argon is stored at higher preassure than co2 so if i buy an argon bottle i can then potentially use it for co2 or argon co2 mix. Is this correct.
Sorry for all the Qs, and thanks in advance for any help
Dan




 
do any of these ????????????