Included in this Instructable is how refill a canister with a hand-held air pump.
Step 1: Materials/Tools Needed
~empty compressed air-canister: contain the compressed air
~bicycle inner tube 12.5": use the bicycle inner tube to get out the inner air valve (to pump air into can)
~epoxy glue: to glue the valve to the canister
~ wire wheel w/ battery-operated drill: used the drill to get rid of the rubber on the air valve
~hand-held pump: to refill canister
~1/4" drill bit: to drill a hole on the bottom of the canister
Step 2: Canister
Empty the canister by getting rid of the pressurized air. Since an air canister is expensive, use it to clean your keyboards. Once it is empty, it is ready to be drilled into.
Step 3: The Valve and Hole
The bicycle inner tube that was used was a 12.5" tube. By cutting out the valve from the inner tube use a wire wheel to get rid of the rubber on the valve. Once the canister is empty, using a quarter inch drill bit and a hand-held battery drill, drill a whole so that the valve from the bicycle tire inner tube will fit.
Placement of the hole can be where ever you chose. The place that I thought was best was the bottom of the canister. It does not show in the picture or when holding the canister. Nothing pops out from the side of the can as well.
Step 4: Epoxy
To seal the valve to the can, use a 2-part epoxy mixture. Once mixed, apply it to the valve and set the valve in place. Using a toothpick to get rid of the excess, and use a hair blow-dryer to speed up the curing time. Once it drys, it's ready to use!
Step 5: Refilling the Canister
By using a hand-held pump, pump into the canister and bam, you're done!