If your having a hard time finding a location... and wouldn't mind driving to Qns. PM a guy on here called triggerman. I believe he knows a location in Qns that will fill up for you. hope this helped some
When the tank is empty you bring it back for a credit. Cost for the gas ends up being around $8 which is a bit high compared to getting your own tank filled. They sell a regulator for use with the co2 tank for driving pneumatic nailers and other air tools. I have one and use it with an 18 guage nailer.