Resend, was dropped..
-------- Original Message --------
Subject: Re: [Homebrew_PCBs] Re:Sprayer pressure
Date: Mon, 14 Mar 2005 09:10:13 -0500
From: uhmgawa <
uhmgawa@...>
To:
Homebrew_PCBs@yahoogroups.comReferences: <
1110754728.436.94819.m12@yahoogroups.com> <
4235544F.4080809@...>
RMustakos wrote:
> As far a nozzles go, in the US, Home Despot has started carrying 1/2 and
> 1/4 inch irrigation equipment, mass produced plastic (not sure what
> kind), with all sorts of nozzles - mist, 45, 90 180 and 360 sprayers,
> all for 5 for two dollars kind of prices. They screw right into 1/4
> inch tubing, and are made to screw into the side of 1/2 inch tube.
"A" for effort I'd say. However these sprayers are intended
for fluid dispersion in a flat horizontal fan pattern rather
than a projectile cone. Yet the fan nozzles found on
plastic hand-pumped bottle sprayers might be worth a try.
Garden chemical sprayers are another possibility as might be
aerosol can spray nozzles.
Speaking of which, as the fluid delivery doesn't need to be
100% continuous, has anyone given any thought to a piston
pump? Should be easy enough to machine from plastic tube
stock. If conventional o-rings will stand up to the etchant
that could be used as a seal. The other possibility is a
diaphragm pump similar to those used in high-end airless
paint sprayers which does achieve 100% duty cycle.
Alternatively to avoid intricate pump components having
to withstand etchant corrosion it would be possible to
use compressed air to pressurize a container of etchant
located below board tank level. This again is not 100%
duty cycle as the etchant must be allowed to gravity
backflow to the etchant container when said container
becomes empty. Achieving this could be as simple as locating
a check valve in the backflow line and bleeding off the
air pressure in the etchant container. The only thing
required to automate the process is a float switch in the
etchant container and a solenoid air valve to alternatively
pressurize/bleed air to/from the etchant container.
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uhmgawa@... www.gnu.org
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uhmgawa@... www.gnu.org