On Jan 21, 5:27, Jeffrey Sharp wrote:
> The goal: extremely localized, high-velocity stream of air. I want to
remove
> dust and crud from those impossible nooks and crannies of classiccmps.
>
> Current solution: canned air - expensive, doesn't work well after one or
two
> minutes of spraying, not really high enough velocity. Bad.
Those cans get flipping cold, don't they?
> Other options:
> - Shop-Vac in reverse operation, fitted with custom cable?
Beware static. And you may find the pressure isn't as high as you'd like.
> - Better, cheaper canned air (does it exist)?
Scuba gear.
> - Dust-removing nano-bots? (jk)
If you find any, let me know :-) Maybe we can retrain/reprogram them to
repair stuff too.
> - Compressor? (I don't know much about these).
I've taken this out of order, because it's what I now use. I bought a
small electric compressor and some air tools (used for other things than
classic computers) for under UKP100 (about US$140). Things to watch out
for:
Compressors are fairly noisy animals. Mine is quiet as such things go, but
still louder than the high-power vacuum cleaner I have.
The vacuum is better than a blower to remove dust (think about where that
dust will go). OTOH, a blower is much better for drying things off, or
getting into things the vacuum+paintbrush can't. The vacuum, however, is
better for spiders.
Any fast-moving air stream can generate static. You can alleviate/prevent
that by using a grounded metal nozzle.
Even a small compressor will deliver pressures well in excess of 100 psi,
and that's way too high for use on electronics. You can rip components off
boards, never mind rip disk heads off. 20-40psi is perfectly adequate, and
it will deliver higher velocity than most aerosol cans give you.
One of the air tools I have is a small pistol-grip-style trigger-operated
blow gun. You can buy them separately for about UKP3, or say $5. For
example, see
http://www.series4.co.uk/s4shop/en-gb/dept_123.html, or
http://www.sip-group.com/PAGES/800x600%20PAGES/Air%20Tools.html (the one I
use looks like 02130, under "Dustres" on that page). These are much easier
than turning the Shop-Vac on and off.
Many compressors include a small amount of oil in the airstream to
lubricate air tools, deliberately added either by an oiler, or as a
byproduct of the oil system used by the piston. However, you can get
oil-less compressors perfectly easily, and oil any tools that need it by
adding a drop in the inlet periodically, or fitting an oiler, or
filter/water-collector/oiler combo, in the airline. They're not expensive.
You can get cheap compressors without a receiver (air tank). Don't bother.
You can also save a few $$$ (not many!) by buying one with a "regulator"
which is really an adjustable blow-off valve to vent the excess air, rather
than a proper pressure-reducing regulator. Given the choice, take the
proper regulator; the compressor will usually also have a cut-off for the
pump to stop it when it gets up to full pressure in the receiver. You
*need* a *good* regulator to run an airbrush properly.
If you want a compressor for other tools besides a blower, remember that
the piston displacement, measured in cu.ft/min, is typically only about 2/3
the available air delivery you'll actually get, and a lot of
hobbyist/low-usage compressor pumps are only rated for a 50% duty cycle (10
minutes on, 10 off, commonly). The pump gets HOT. If you ever plan on
using something like a die grinder, you want a compressor rated for about
three times (or more) the listed air consumption of the tool.
If you buy quick-release couplings, be aware there are at least three
standards, and they're not interchangeable.
I'd recommend buying a small compressor. Mine is great, though I sometimes
wish I'd bought a slightly bigger one. Whether you buy a scuba tank or a
compressor, just think of the cost and inconvenience of ten cans of
high-pressure air duster.
--
Pete Peter Turnbull
Network Manager
University of York
Received on Tue Jan 21 2003 - 14:53:00 GMT