What is the volume of etchant that has to be pumped, say in Gal/Min?
From:
Homebrew_PCBs@yahoogroups.com [mailto:
Homebrew_PCBs@yahoogroups.com]
On Behalf Of jcarlosmor
Sent: Monday, August 20, 2012 11:37 AM
To:
Homebrew_PCBs@yahoogroups.comSubject: [Homebrew_PCBs] Re: Kepro bench top spray ectcher
Hello Tom,
Thank you very much for your detailed information. I agree with you that the
pumps in this unit get damaged very soon, and need continous replacement.
Also, I am planning just to build a new spray etching tank form scratch. In
the web there are some pages about that. I believe some detailed
construction plans are in the "instructables" site, and some german web page
also details construction, but for a central rotary spindler etch machine.
Most etching tanks of the 80s were made of PVC, but Polypropylene seems also
a good choice now. ¿Does anyone knows if PP can be cemented, like PVC, and
how well can whistand the FeCl and CuCl? Most PP tanks are welded instead.
The beauty of the old Kepro spray developers amd spray etching tanks was
their simplicity. No sophisticated noozles, no adjusting pipes, etc. Just a
tank with very simple spray bars, the mesh diffusers, and even at ambient
temperature your double sided 12x12 inch PCB was ready in a less than five
minutes.
Tom, some photos of your Kepro spray system also would be very helpful for
everyone interested in building their own DIY spray etch. I understand that
the construction of such device may not be worth the time and money for the
ocassional DIY PCB maker with only a few PCBs per month, but if you have
some space in your basement, and often you make PCBs in a regular basis, the
addition of a spray etch system it would be very helpful.
Regards.
--- In
Homebrew_PCBs@yahoogroups.com<mailto:Homebrew_PCBs%40yahoogroups.com> , "twb8899" <twb8899@...> wrote:
>
> In my last message I tried to show how the spray manifold drill pattern
would look but it didn't post correctly. This time I'll add some hyphens so
it spaces properly and I think you will get the idea.
>
> -----------------------------------------------------
> O------O------O------O------O------O------O------O
>
> ---O------O------O------O------O------O------O
>
> O------O------O------O------O------O------O------O
> -----------------------------------------------------
>
> If this doesn't post correctly I'll make a drawing or take some photos and
post them later.
>
> Tom
>
>
> --- In Homebrew_PCBs@yahoogroups.com
<mailto:Homebrew_PCBs%40yahoogroups.com> , "jcarlosmor" <jcarlosmor@> wrote:
> >
> >
> >
> >
> > Hello Tom,
> >
> > I had obtained a used Kepro bench-top etcher. It is a very old machine
(mid-80s I believe), but I had seen those machines in action many years ago
and the performance is outstanding for fast etching of batch PCBs.
> >
> > The problem is that some parts are missing and/or require fixing. The
two spray bars are lost. That is no problem because I can buy, cut, and
cement 1/2" PVC as the originals manifolds. The problem is that I do not
remember how many holes were in every spray bar. I remember that the hole
size is about 1/16" ¿Am I correct?, since I used a drill bit of this size to
clean of debris in the spray bars in those etchers many years ago. Do you
recall how many holes, what distance between them, and the angle of up/down
orientation in your Kepro etcher? I know that these details are very
important to obtain the maximum performance of these units.
> >
> > Thank you very much in advance for any help.
> >
> >
> >
> >
> > --- In Homebrew_PCBs@yahoogroups.com
<mailto:Homebrew_PCBs%40yahoogroups.com> , "twb8899" <twb8899@> wrote:
> > >
> > > Grant,
> > >
> > > You could try using one of the Little Giant pumps. I haven't bought
> > > one of these pumps in years but they used to cost about $25 from WW
> > > Grainger. Kepro uses this small pump in their etchers. They modify
> > > the pump by removing the metal impeller and installing one made from
> > > PVC plastic. There are two pumps in the machine, one for each side.
> > > The manifold is made from 1/2" CPVC pipe. The pipe has about twenty
> > > or so small holes drilled to give the spray pattern. A piece of
> > > plastic window screen hangs between the manifold (spray bar) and the
> > > part to be etched. This screen is used to disperse the spray pattern
> > > across the board for even etching. It works pretty good with 1 ounce
> > > copper taking about 4 minutes to etch with ferric chloride.
> > >
> > > Tom
> > >
> >
>
[Non-text portions of this message have been removed]