A "Swamp" cooler is a type of air conditioning device that works by
the evaporation process to cool air. They are very simple. Water is pumped
to the top of panels usually filled with burlap or hemp fibers. The water
runs down through the fibers soaking them. Air is then pulled through the
fiber panels and blown into the room. As the air is pulled through the
fibers it picks up maximum humidity. Once released into the room the air
evaporates its excess humidity to conform with
current atmospheric conditions. As the water is released from the air it
takes heat with it. Air itself is a very poor storage medium for heat and
stores most of its heat in the moisture contained in it.
Swamp pumps can be purchased at most hardware stores and even walmart.
On Tue, Jan 29, 2013 at 7:26 AM, Jeff Heiss <jeff.heiss@...> wrote:
> ∗∗
>
>
> Todd, I like your ideas. What is a "swamp" cooler pump? I am not familiar
> with drip irrigation spray heads. Are they like mister nozzles for gardens?
>
> Jeff
>
>
> -----Original Message-----
> From: Todd F. Carney k7tfc@...>
> Sent: Tuesday, January 29, 2013 2:35 AM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: Re: [Homebrew_PCBs] thoughts on electric paint sprayer for spray
> etching
>
> On Mon, Jan 28, 2013 at 8:47 PM, Jeff jeff.heiss@...> wrote:
> >
> > What are opinions on using an electric paint sprayer to spray etch a
> > board? Could an electric sprayer be modified to run etchant so it can
> > resist corroding? Would the spray pattern, droplet size, and spray force
> be
> > acceptable?
> >
>
> Jeff,
>
> Just to clarify, do you mean for the sprayer to resist corrosion? If you
> use ferric chloride, that doesn't seem likely. Maybe not even a persulfate
> etchant.
>
> I used to use shop-built bench-top (actually, lab-sink-top) spray-based
> etching machine that was pretty much all plastic. It consisted of an
> open-top plastic tank, an immersion heater (from a small hot-water heater),
> an immersion pump from a "swamp" cooler, and sprayers made of PVC pipe, and
> a holder that clamped the board to be etched in a frame. The sprayers hit
> the board evenly on both sides at once. The little spray heads were made
> for drip-irrigation use. We placed a sheet of plexiglass on top to contain
> overspray and so we could monitor the etching. We used persulfate etchant
> in it (which we left in it until it had to be replaced) so it was not a
> source of staining-or-toxic ferric chloride. I don't know how or if that
> damn stuff would work in such a machine. We never used it. I don't think
> any professional or commercial pcb outfits use it either.
>
> These days, a darkroom tray works for the one or two boards I might make in
> a month. I use home-made peroxide-muriatic-salt etchant. I just hand
> agitate the tray. I was toying with the idea of making a motorized rocking
> agitator, but then I came to my senses.
>
> 73,
>
> Todd
>
> ----------------------------------------------------------
> K7TFC / Medford, Oregon, USA / CN82ni / UTC-8
> ----------------------------------------------------------
> QRP (CW & SSB) / EmComm / SOTA / Homebrew / Design
>
> [Non-text portions of this message have been removed]
>
> [Non-text portions of this message have been removed]
>
>
>
--
If you ask me if it can be done. The answer is YES, it can always be done.
The correct questions however are... What will it cost, and how long will
it take?
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