I found some at an electronic surplus store.
Branded "MG Chemicals", content description says "Tetrafluoretane"
Can't remember exacltly what ws the name they gave it, something along the lines of "Super Duster ###"
Only place I found some. At the radio shack thing I only found difluo....
or just get a propane adaptor... ran a plastic slide for a while on it.... when it breaks, you have save enought from using propane to buy a new metal slide...
*edit* jsut realized that was the same thing.... thx Identity!