>Air duster cans containing just plain air are available ... but don't buy
>them: they quickly run out of pressure because the contents is just
>compressed gas. Some gasses (like R134 and "Freon") liquify at reasonably
>low pressure, so a can of R134 is mostly liquid that gradually returns
>to gaseous state as it is allowed to escape. Result: a can of R134 gives
>much more gas than a same-size can of air (which doesn't liquify at can
>pressure), and the nozzle pressure remains constant until the last bit of
>liquid in the can boils off.

Thanks for the info. My concerns about air duster gasses are purely cost -
all the ones I've seen are tetrafluoroethane (R134a) and cost about $10/can!
I figured maybe there was a cheaper alternative to this.

I was thinking an air compressor would work, but that's likely too much
pressure and moisture. The main thing I use air dusters for is cleaning
boards and fans/air intake.

Chris