On Sat, 21 Jun 2008 00:18:22 -0400, "Skeleton Man"
<invalid@guestwho.com> wrote:

>>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.


An air compressor can have a valve to regulate pressure, or
you could choose one that just doesn't produce high flow
rate, thus causing the pressure to drop quickly at any
distance from the nozzle.

Moisture is not an issue. Don't use a compressor that puts
oil in the lines for power tool use.

You don't actually need to use compressed air, a small paint
brush will do fine and costs about $1. You can get empty
cans with a refill port but they won't last nearly as long
as a pre-filled can of *air* before having to be refilled
again.

http://www.shoplet.com/office/db/g15978.html

Another idea is a CO2 cannister like you'd find on a
paintball gun, then you just need the fittings, valve and
hose. Surely somebody has that, you'd just have to hunt
down the parts or possibly make it yourself by buying the
separate fittings and hose then crimping it together.