Much of what you need has already been worked-out, and worked
with.........
How about this bit of detail on a fellows working etch system ????
**********from etch1...
"I also made a tank with a higher-pressure pump, and plastic nozzles
to spray the ferric chloride onto the sheet, with a clip to suspend
the sheet vertically in the tank above the surface of the acid. This
worked much better (about 4 times faster than the circulating tank!)
and I even had to dilute the ferric chloride about 1:1 with distilled
water to slow down the etching action. The surface finish was much
smoother also. But, the etching was "directional" due to the acid
running off the surface in one direction. I had to keep stopping the
pump, and rotating the sheet 1/4 turn every so often to even out the
directionality."...................
"There are two nozzles (equivalent to #H-83251-00 on pg. 1123 of the
1995 Cole-Parmer laboratory products catalog) in the wall of the tank
directly across from one another, each fed by an oscillating pump.
These pumps (equivalent to #H-07101-01 on pg. 1113 of the Cole-Parmer
catalog) are made for laboratory use, and have all rubber/plastic
internal parts. Unfortunately, the pumps do not put out enough
pressure to completely atomize the etchant, but the spray is fine
enough for the finest etching I do. I can turn each pump on
individually, to fine-tune the double-sided etching. All plumbing is
vinyl tubing with plastic fittings and hose clamps."
"A shaft (titanium, to resist the acid, as even stainless steel will
dissolve in the ferric chloride eventually) comes in the side next to
one nozzle, so I can hold the sheet in the middle of the tank, and
turn it continuously while etching. To hold the brass while etching,
I drill a ~2mm hole near each corner. A four-armed titanium wire
"spider" with hooked ends engages these holes, and applies outward
tension to keep the sheet from bowing. The plastic hub of this spider
presses onto the titanium shaft."
**********from etch2......
"I am using a 300W aquarium heater, built like a long test tube with
the power cord and temperature adjustment knob coming out a plastic
cap on the end. Although it is completely submersible, I did not want
to take chances. I drilled a hole in the side of the tank (adjacent
to the bypass outlet) and used silicone caulk to seal the heater in,
with just the plastic head outside the tank. A small plastic bracket
glued onto the inner wall of the sump supports the other end of the
heater. It is just a 1/4" thick piece of acrylic with a hole in it."
"The new tank worked very well, but I had two failures where the
outlet tubing slipped off the barbed fittings, even though I was
using the nylon "snappy" hose clamps. I replaced all the outlet
plumbing with 1/2" PVC pipe, glued. I turned up an adapter from PVC
barstock that plugs into the pump outlet port (duplicating the stock
adapter) and has a spud to glue into the PVC fitting."
**********
http://www.prototrains.com/etch1/etch1.html
http://www.prototrains.com/etch2/etch2.html
I think he got his titanium from Smallparts.com ...... at least they
have it for sale.
"This article is ©1998-2007 Randy Gordon-Gilmore. No part of this
article may be republished without permission. Private copying for
non-profit-making purposes is permitted, as long as credit is given.
Last updated: 26 Feb 2007."
Best to ya'
Mike Bauers
Milwaukee Wi, USA
Show quoted textHide quoted text
On Apr 29, 2008, at 5:27 AM, Leon wrote:
> Has anyone tried ultrasonics? The cavitation on the copper surface
> should
> speed up the etching process considerably.
>
> Leon