Homebrew_PCBs

I am contemplating using CuCl and HCl as etchant and wonder if this
pump (described below) would withstand this etchant. The concentration
of Hcl would be 5% max.

"Compact motor driven centrifugal pump. The pump is magnetically
driven and has no shaft seals to wear out or leak. The motor is a
shaded pole design and is rated 220 VAC 50/60 Hz 0.22 amp,continuous
duty. The pump body and impeller are constructed from Vectra® plastic.
Theimpeller shaft is ceramic and all internal seals are of Viton®. The
thrust washer isconstructed from Teflon®/fiberglass. The pump output
is 3.75 gal. per minute. Maximumhead is 5.6 feet. Maximum system
working pressure is 75 psi. The pump ports are barbstyle, designed to
work with flexible tubing."

Comments?

Grant

The pump sounds like its designed for chemicals. HCl + CuCl will be just
fine, but I'd be more worried if you have enough pressure to properly
power spray nozzles. I wanted to do similar thing with the mag. drive
pumps I own but learned most spray nozzles need pressures above 10
meters head. Spraying uses up a lot of pump energy.



grantfair2001 wrote:

>I am contemplating using CuCl and HCl as etchant and wonder if this
>pump (described below) would withstand this etchant. The concentration
>of Hcl would be 5% max.
>
>"Compact motor driven centrifugal pump. The pump is magnetically
>driven and has no shaft seals to wear out or leak. The motor is a
>shaded pole design and is rated 220 VAC 50/60 Hz 0.22 amp,continuous
>duty. The pump body and impeller are constructed from Vectra® plastic.
>Theimpeller shaft is ceramic and all internal seals are of Viton®. The
>thrust washer isconstructed from Teflon®/fiberglass. The pump output
>is 3.75 gal. per minute. Maximumhead is 5.6 feet. Maximum system
>working pressure is 75 psi. The pump ports are barbstyle, designed to
>work with flexible tubing."
>
>Comments?
>
>Grant
>
>
>
>Be sure to visit the group home and check for new Bookmarks and files:
>http://groups.yahoo.com/group/Homebrew_PCBs
>
>To unsubscribe from this group, send an email to:
>Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>

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

Thanks Tom. I looked at the Grainger site but it showed about 100
Little Giant pumps ranging in price from $25 to several hundred. ANy
idea how to narrow this down?

Grant

--- In Homebrew_PCBs@y..., "twb8899" <twb8899@y...> 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.
> Tom

Grant,

The part number for this pump is CP-6500. Another source is Johnstone
Supply. Their catalog number is B80-943. Catalog price is $16.59
(US). www.johnstonesupply.com

The catalog info says this pump can handle "mild acid-alkali
transfer". Has a four blade nylon impeller molded to the shaft. This
must be a new version. The older Kepro etchers had a modified PVC
impeller and shaft since these parts used to be metal. This pump will
move 225 gph at a 3 foot head. This pump will move a lot of etchant,
just ask anyone who accidently opened the lid of a Kepro ecther while
it was running !!!

Tom

Thanks Tom. I will pick one up when I am vacationing in the US next
week. I appreciate your help.

Grant

]--- In Homebrew_PCBs@y..., "twb8899" <twb8899@y...> wrote:

> Grant,
>
> The part number for this pump is CP-6500. Another source is

Johnstone

> Supply.

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, "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
>

hello ^^)

----- Original Message -----
From: "jcarlosmor" <jcarlosmor@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Sunday, August 19, 2012 1:39 AM
Subject: [Homebrew_PCBs] Kepro bench top spray ectcher

> 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.

did you try to look there for infos ? : http://www.dalpro.net/EQUIPMENT.html
and there for howto : www.dalpro.net/HOWTO.html ^^)

hope you find what you need ^^)

Amigalement,
JF

The spray manifold on the Kepro etchers are nothing more than two pieces of 1/2" CPVC pipe with a pattern of small holes spaced out over a 5 or 6 inch length.

The drilled holes are about 1/16" and drilled in a pattern something like this:


-------------------------------------------
O O O O O O
O O O O O
O O O O O O
-------------------------------------------


The manifold is made from a "T" fitting with two pieces of drilled pipe plugged into each side for an overall length of about 12". Nothing is glued except for the end caps. The pieces are press fit together so you can adjust the spray pattern. The spray manifold is spaced about 3" from the board surface.

About half way between the spray manifold and the board is a piece of fiberglass screen to break up the spray pattern for better distribution over the entire board surface. The screen has a heavy strip of PVC plastic glued to the bottom to keep it in place when the pumps are spraying.

The spray manifold is positioned closer to the top of the board so the etchant can run across the board surface as it falls back to the sump. These etching machines work pretty good and are simple to make. The main problem with the Kepro units was pump failure. Substituting a better pump is a wise thing to do or find a better way to seal the pump shaft and bearings from etchant fumes.

Tom

--- In Homebrew_PCBs@yahoogroups.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, "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
> >
>

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, "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, "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
> >
>

In other words, the holes are "staggered".
If I recall correctly, virtually every part of the Kepro sysems can be
described as "general hardware...off the shelf"
So, nearly all of the units can be easily repaired by stuff you can buy
at a comprehensive hardware store or from
sellers on ebay. Just make sure you use stainless steel heater elements
in the etch tank and in the coated PC board
dryer cabinet.

Roland F. Harriston


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]

Hello Jean-Francois,

Thank you for your reply.

Yes, I already know that Dalpro continue with all the former line of products of Kepro. However, the spray bars used in this machine are so simple that anyone can make them in a couple of hours or so.

Regards.

--- In Homebrew_PCBs@yahoogroups.com, Jean-François Bachelet <boogly63@...> wrote:
>
> hello ^^)
>
> ----- Original Message -----
> From: "jcarlosmor" <jcarlosmor@...>
> To: <Homebrew_PCBs@yahoogroups.com>
> Sent: Sunday, August 19, 2012 1:39 AM
> Subject: [Homebrew_PCBs] Kepro bench top spray ectcher
>
> > 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.
>
> did you try to look there for infos ? : http://www.dalpro.net/EQUIPMENT.html
> and there for howto : www.dalpro.net/HOWTO.html ^^)
>
> hope you find what you need ^^)
>
> Amigalement,
> JF
>

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, "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, "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, "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
> > >
> >
>

PP is difficult to glue, weld it instead.

ST

On Mon, Aug 20, 2012 at 8:36 PM, jcarlosmor <jcarlosmor@...> wrote:

> 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.
>

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.com
Subject: [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]

It is hard to know the real amount. The spray etchers of that time only include some a few specifications.

The Kepro BTE-202 and BTE-201 used a Little Giant pump model CP-6500, Product #540004. That part is not manufactured anymore. It is replaced by model CP1-115.

The original CP-6500 has the following specifications:
PRODUCT #540004, MODEL CP-6500
FOR COOLERS UP TO 6500 C.F.M.
115v. 60 Hz, .85 amps, 1 PH

The new model available is:
PRODUCT #540005, MODEL CP1-115
1/70 HP, 115/127v., Capacity 307 GPH@1', 5000-7500 CFM

According to specifications and graph table (which appears in the Little Giant catalog) the newest pump moves about 300 Galons per hour, for a typical 50 cms of head above the sump of the etchant to the spray bars.

Those figure may be considered with care, since I remember that none of the spray etchers manufacturers specify that measure in their units.

--- In Homebrew_PCBs@yahoogroups.com, "Andrew Volk" <amvweb@...> wrote:
>
> 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.com
> Subject: [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]
>

Hi Guy's,

Is there any info on how the CP1-115 pump handles the different etchants?

I had started to build a spray etcher and found a pump from Little Giant Pumps that would handle medium power etchant, but the pump was over $100.00.

Do you know if this pump will handle the FeCl and such, for sure? Because you can get them for under $40.00 easy on the net.

If the pump will handle it I get out the spray unit and I'll be ordering the pump ASAP, the spray arms and such no problem.

Also, for those wondering where to get the diffuser, blank low thread screen printer screens, I checked it out way back with water, does the job nicely.

Best Regards,

Kevin I.




________________________________
From: jcarlosmor <jcarlosmor@...>
To: Homebrew_PCBs@yahoogroups.com
Sent: Monday, August 20, 2012 7:55 PM
Subject: [Homebrew_PCBs] Re: Kepro bench top spray ectcher




It is hard to know the real amount. The spray etchers of that time only include some a few specifications.

The Kepro BTE-202 and BTE-201 used a Little Giant pump model CP-6500, Product #540004. That part is not manufactured anymore. It is replaced by model CP1-115.

The original CP-6500 has the following specifications:
PRODUCT #540004, MODEL CP-6500
FOR COOLERS UP TO 6500 C.F.M.
115v. 60 Hz, .85 amps, 1 PH

The new model available is:
PRODUCT #540005, MODEL CP1-115
1/70 HP, 115/127v., Capacity 307 GPH@1', 5000-7500 CFM

According to specifications and graph table (which appears in the Little Giant catalog) the newest pump moves about 300 Galons per hour, for a typical 50 cms of head above the sump of the etchant to the spray bars.

Those figure may be considered with care, since I remember that none of the spray etchers manufacturers specify that measure in their units.

--- In Homebrew_PCBs@yahoogroups.com, "Andrew Volk" <amvweb@...> wrote:
>
> 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.com
> Subject: [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]
>




[Non-text portions of this message have been removed]

Kevin,

All of those pumps have stainless steel metal shafts, who impose a problem for etching. However, those units are the kind that have been used for spray etching. They often need replacement in a regular basis. I do not know if someone could point out us for some kind of magnetic drive pump that it is entirely of plastic in their conducts with the fluid. Also, someone did comment that earlier Kepro spray etchers had modified Little Giant pumps, I think that modifying the metal shaft and impeller with another of plastic. I am not sure about how to accomplish that.

Regards.

--- In Homebrew_PCBs@yahoogroups.com, Kevin Impson <internetgiest@...> wrote:
>
> Hi Guy's,
>
> Is there any info on how the CP1-115 pump handles the different etchants?
>
> I had started to build a spray etcher and found a pump from Little Giant Pumps that would handle medium power etchant, but the pump was over $100.00.
>
> Do you know if this pump will handle the FeCl and such, for sure? Because you can get them for under $40.00 easy on the net.
>
> If the pump will handle it I get out the spray unit and I'll be ordering the pump ASAP, the spray arms and such no problem.
>
> Also, for those wondering where to get the diffuser, blank low thread screen printer screens, I checked it out way back with water, does the job nicely.
>
> Best Regards,
>
> Kevin I.
>
>
>
>
> ________________________________
> From: jcarlosmor <jcarlosmor@...>
> To: Homebrew_PCBs@yahoogroups.com
> Sent: Monday, August 20, 2012 7:55 PM
> Subject: [Homebrew_PCBs] Re: Kepro bench top spray ectcher
>
>
> Â
>
> It is hard to know the real amount. The spray etchers of that time only include some a few specifications.
>
> The Kepro BTE-202 and BTE-201 used a Little Giant pump model CP-6500, Product #540004. That part is not manufactured anymore. It is replaced by model CP1-115.
>
> The original CP-6500 has the following specifications:
> PRODUCT #540004, MODEL CP-6500
> FOR COOLERS UP TO 6500 C.F.M.
> 115v. 60 Hz, .85 amps, 1 PH
>
> The new model available is:
> PRODUCT #540005, MODEL CP1-115
> 1/70 HP, 115/127v., Capacity 307 GPH@1', 5000-7500 CFM
>
> According to specifications and graph table (which appears in the Little Giant catalog) the newest pump moves about 300 Galons per hour, for a typical 50 cms of head above the sump of the etchant to the spray bars.
>
> Those figure may be considered with care, since I remember that none of the spray etchers manufacturers specify that measure in their units.
>
> --- In Homebrew_PCBs@yahoogroups.com, "Andrew Volk" <amvweb@> wrote:
> >
> > 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.com
> > Subject: [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]
> >
>
>
>
>
> [Non-text portions of this message have been removed]
>

> All of those pumps have stainless steel metal shafts, who impose a >problem for etching. However, those units are the kind that have been >used for spray etching. They often need replacement in a regular >basis. I do not know if someone could point out us for some kind of >magnetic drive pump that it is entirely of plastic in their conducts >with the fluid. Also, someone did comment that earlier Kepro spray >etchers had modified Little Giant pumps, I think that modifying the >metal shaft and impeller with another of plastic. I am not sure about >how to accomplish that

Take look at www.usplastics.com they list Magnetic Drive Pumps. I have never used them and prices may not be the cheapest but should give you some ideas and model # to look for.

Ben

From the thread: "Kepro bench top spray etcher":

An eBay search for:

magnetic pump

produces hundreds of results, some of them for small pumps costing less
than $100. Sorting by "price with shipping" groups similar products
together.

Perhaps not every one of them has a magnetically coupled impeller -
thereby presumably having no metal shaft or seals which could be
attacked the the etchant. Maybe some of these are truly magnetically
coupled, with an impeller magnet totally sealed in plastic, and with
enough pressure to drive spray nozzles.

I think the challenge is to find one or more to make a compact
double-sided spray arrangement, with a smallish amount of etchant.
Prices are USD$ with shipping to Australia.

. http://www.ebay.com/itm/221017721016 $27
. Anti corrosion. 5 litres per minute.

. http://www.ebay.com/itm/221109440478 $20
. Probably too small.

. http://www.ebay.com/itm/270961751604 $25
. Probably too small, but has photos of the magnetic drive system.

. http://www.ebay.com/itm/130481962264 $21
. Another small cheapie - photo shows magnetic drive system.

. http://www.ebay.com/itm/180947111931 $30 + $53 shipping
. Iwaki 100V AC induction motor, uses a capacitor to phase lag the
. second winding. Is the capacitor internal or external?. From a
. photographic processing machine. 6 available.
. At 50Hz, 11 litres/min. Max head 1.5 metres.

. http://www.ebay.com/itm/180955597871 $70 + $80 shipping
. Larger Iwaki pump, one only. 27 litres/min 3.1 metre max head.
. This would be be highly suitable.

. http://www.ebay.com/itm/180954727143 $90 + $135
. Larger Iwaki pump.

. http://www.ebay.com/itm/130681739875 $50 + $51
. Iwaki-Walchem New Old Stock. 220VAC high capacity.

. http://www.ebay.com/itm/130743582615 $83
. High capacity 24 volt with speed control. This is a brushless
. motor, meaning it has electronics to drive three (I guess)
. windings, with a permanent magnet rotor which follows the resultant
. rotating magnetic field. The rotor's shaft is ceramic. So I think
. there is no motor -> magentic coupler, just that the permanent magnet
. rotor and its shaft and bearings can be exposed to liquids without
. being damaged. Many sellers have this item.

The above pumps are centrifugal.

This one is dual interlocking gears, which I think might be better for
producing higher pressures for the restricted flow of a spray system:

. http://www.ebay.com/itm/280929962685? $11
. It is quite small, but if it really is immune to corrosion, then
. two or more could be used, since they are so inexpensive.
. Multiple sellers have the same item.

. http://www.ebay.com/itm/250810139654 $29 + $43
. Another gear pump, with no motor. The pipe fittings could be tricky.
. Up to half a litre per minute, which is rather small. Maximum
. pressure is 75 pounds per square inch, which is very high.

Searching now on:

Iwaki pump

. http://www.ebay.com/itm/350587388542 $25 + $47
. One only, Iwaki bellows pump 220VAC.

. http://www.ebay.com/itm/140813153579 $90 + $48
. Extra high pressure Iwaki pump with magnetic coupling arrangement
. clearly shown in photos. Comes with useful-looking hose fittings.

There are many more Iwaki magnetically coupled pumps costing more than
$100. I guess there are lots of now-obsolete photographic processing
systems being broken up for parts.

- Robin http://www.firstpr.com.au/pcb-diy/

Has anyone looked at peristaltic pumps? The only thing that comes in
contact to the etchant is the rubber hose that goes through the pump. I got
one off of eBay, as well. The only issue with this kind of pump or the less
expensive pumps in this thread is the volume they can push.



Andy



From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Robin Whittle
Sent: Tuesday, August 21, 2012 9:03 PM
To: Homebrew_PCBs@yahoogroups.com
Cc: Ben L
Subject: [Homebrew_PCBs] Magnetic drive pumps for spray etchers





From the thread: "Kepro bench top spray etcher":

An eBay search for:

magnetic pump

produces hundreds of results, some of them for small pumps costing less
than $100. Sorting by "price with shipping" groups similar products
together.

Perhaps not every one of them has a magnetically coupled impeller -
thereby presumably having no metal shaft or seals which could be
attacked the the etchant. Maybe some of these are truly magnetically
coupled, with an impeller magnet totally sealed in plastic, and with
enough pressure to drive spray nozzles.

I think the challenge is to find one or more to make a compact
double-sided spray arrangement, with a smallish amount of etchant.
Prices are USD$ with shipping to Australia.

. http://www.ebay.com/itm/221017721016 $27
. Anti corrosion. 5 litres per minute.

. http://www.ebay.com/itm/221109440478 $20
. Probably too small.

. http://www.ebay.com/itm/270961751604 $25
. Probably too small, but has photos of the magnetic drive system.

. http://www.ebay.com/itm/130481962264 $21
. Another small cheapie - photo shows magnetic drive system.

. http://www.ebay.com/itm/180947111931 $30 + $53 shipping
. Iwaki 100V AC induction motor, uses a capacitor to phase lag the
. second winding. Is the capacitor internal or external?. From a
. photographic processing machine. 6 available.
. At 50Hz, 11 litres/min. Max head 1.5 metres.

. http://www.ebay.com/itm/180955597871 $70 + $80 shipping
. Larger Iwaki pump, one only. 27 litres/min 3.1 metre max head.
. This would be be highly suitable.

. http://www.ebay.com/itm/180954727143 $90 + $135
. Larger Iwaki pump.

. http://www.ebay.com/itm/130681739875 $50 + $51
. Iwaki-Walchem New Old Stock. 220VAC high capacity.

. http://www.ebay.com/itm/130743582615 $83
. High capacity 24 volt with speed control. This is a brushless
. motor, meaning it has electronics to drive three (I guess)
. windings, with a permanent magnet rotor which follows the resultant
. rotating magnetic field. The rotor's shaft is ceramic. So I think
. there is no motor -> magentic coupler, just that the permanent magnet
. rotor and its shaft and bearings can be exposed to liquids without
. being damaged. Many sellers have this item.

The above pumps are centrifugal.

This one is dual interlocking gears, which I think might be better for
producing higher pressures for the restricted flow of a spray system:

. http://www.ebay.com/itm/280929962685? $11
. It is quite small, but if it really is immune to corrosion, then
. two or more could be used, since they are so inexpensive.
. Multiple sellers have the same item.

. http://www.ebay.com/itm/250810139654 $29 + $43
. Another gear pump, with no motor. The pipe fittings could be tricky.
. Up to half a litre per minute, which is rather small. Maximum
. pressure is 75 pounds per square inch, which is very high.

Searching now on:

Iwaki pump

. http://www.ebay.com/itm/350587388542 $25 + $47
. One only, Iwaki bellows pump 220VAC.

. http://www.ebay.com/itm/140813153579 $90 + $48
. Extra high pressure Iwaki pump with magnetic coupling arrangement
. clearly shown in photos. Comes with useful-looking hose fittings.

There are many more Iwaki magnetically coupled pumps costing more than
$100. I guess there are lots of now-obsolete photographic processing
systems being broken up for parts.

- Robin http://www.firstpr.com.au/pcb-diy/





[Non-text portions of this message have been removed]

Something fun to think about or play around with:

FeCl (and probably other etchants as well) is quite conductive.

Now, conductive materials like to stay fixed with respect to magnetic
fields. See https://www.youtube.com/watch?v=f43fXde2S78 for a
demonstration. The penny is dragged along by a strong magnet.

See where I'm going with this? A spinning magnet (where the poles
sweep around) should be able to drag conductive liquids through a tube
that is wrapped around the spinning magnet.

In fact you don't even need a spinning magnet. You can create a
rotating magnetic field with electromagnets (for example, remove the
rotor from a three-phase motor - but use lower voltage when the rotor
is removed or you'll burn up the windings and/or blow a fuse). You can
pump conductive liquids with no moving parts at all!

As a bonus, induced current in the liquid would cause heating, so you
might get your etchant heated as it is being pumped!

Enjoy!
- Jan

> An eBay search for:
>
> magnetic pump
>
> produces hundreds of results, some of them for small pumps costing less

than

> $100. Sorting by "price with shipping" groups similar products together.
>
> Perhaps not every one of them has a magnetically coupled impeller -

thereby

> presumably having no metal shaft or seals which could be attacked the the
> etchant. Maybe some of these are truly magnetically coupled, with an

impeller

> magnet totally sealed in plastic, and with enough pressure to drive spray
> nozzles.

I've got a couple of those that I paid $20 for
(http://www.ebay.com.au/itm/280877928450), mine are 24V @ 1A, and claim
12.5L/min. The power rating is correct, I haven't checked the flow rate but
it does indeed pump water at a fair rate. It didn't mention pressure, and I
haven't tried. Presumably the same as another 24W pump.

They are also magnetically coupled, the impeller & shaft (with magnet) can
be removed, it has no metal.

I did read a bit of grumbling somewhere about how some type of acid would
attack the plastic and fail after a few weeks, I gathered this was the type
of pump they were talking about. I'm only using water so that's not a
problem, I can't advise on reliability either. I'm also running it in air,
not submerged.

Mine seems to match its advertising.

Tony

Hello Andy,

Unfortunately, peristaltic pumps are not suitable for obtaining the necessary flow and pressure for spray ecthing. I had reviewed some of the earlier 80's spray etcher models, and nobody was using a peristaltic pump.

Regards.

--- In Homebrew_PCBs@yahoogroups.com, "Andrew Volk" <amvweb@...> wrote:
>
> Has anyone looked at peristaltic pumps? The only thing that comes in
> contact to the etchant is the rubber hose that goes through the pump. I got
> one off of eBay, as well. The only issue with this kind of pump or the less
> expensive pumps in this thread is the volume they can push.
>
>
>
> Andy
>
>
>
> From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
> On Behalf Of Robin Whittle
> Sent: Tuesday, August 21, 2012 9:03 PM
> To: Homebrew_PCBs@yahoogroups.com
> Cc: Ben L
> Subject: [Homebrew_PCBs] Magnetic drive pumps for spray etchers
>
>
>
>
>
> From the thread: "Kepro bench top spray etcher":
>
> An eBay search for:
>
> magnetic pump
>
> produces hundreds of results, some of them for small pumps costing less
> than $100. Sorting by "price with shipping" groups similar products
> together.
>
> Perhaps not every one of them has a magnetically coupled impeller -
> thereby presumably having no metal shaft or seals which could be
> attacked the the etchant. Maybe some of these are truly magnetically
> coupled, with an impeller magnet totally sealed in plastic, and with
> enough pressure to drive spray nozzles.
>
> I think the challenge is to find one or more to make a compact
> double-sided spray arrangement, with a smallish amount of etchant.
> Prices are USD$ with shipping to Australia.
>
> . http://www.ebay.com/itm/221017721016 $27
> . Anti corrosion. 5 litres per minute.
>
> . http://www.ebay.com/itm/221109440478 $20
> . Probably too small.
>
> . http://www.ebay.com/itm/270961751604 $25
> . Probably too small, but has photos of the magnetic drive system.
>
> . http://www.ebay.com/itm/130481962264 $21
> . Another small cheapie - photo shows magnetic drive system.
>
> . http://www.ebay.com/itm/180947111931 $30 + $53 shipping
> . Iwaki 100V AC induction motor, uses a capacitor to phase lag the
> . second winding. Is the capacitor internal or external?. From a
> . photographic processing machine. 6 available.
> . At 50Hz, 11 litres/min. Max head 1.5 metres.
>
> . http://www.ebay.com/itm/180955597871 $70 + $80 shipping
> . Larger Iwaki pump, one only. 27 litres/min 3.1 metre max head.
> . This would be be highly suitable.
>
> . http://www.ebay.com/itm/180954727143 $90 + $135
> . Larger Iwaki pump.
>
> . http://www.ebay.com/itm/130681739875 $50 + $51
> . Iwaki-Walchem New Old Stock. 220VAC high capacity.
>
> . http://www.ebay.com/itm/130743582615 $83
> . High capacity 24 volt with speed control. This is a brushless
> . motor, meaning it has electronics to drive three (I guess)
> . windings, with a permanent magnet rotor which follows the resultant
> . rotating magnetic field. The rotor's shaft is ceramic. So I think
> . there is no motor -> magentic coupler, just that the permanent magnet
> . rotor and its shaft and bearings can be exposed to liquids without
> . being damaged. Many sellers have this item.
>
> The above pumps are centrifugal.
>
> This one is dual interlocking gears, which I think might be better for
> producing higher pressures for the restricted flow of a spray system:
>
> . http://www.ebay.com/itm/280929962685? $11
> . It is quite small, but if it really is immune to corrosion, then
> . two or more could be used, since they are so inexpensive.
> . Multiple sellers have the same item.
>
> . http://www.ebay.com/itm/250810139654 $29 + $43
> . Another gear pump, with no motor. The pipe fittings could be tricky.
> . Up to half a litre per minute, which is rather small. Maximum
> . pressure is 75 pounds per square inch, which is very high.
>
> Searching now on:
>
> Iwaki pump
>
> . http://www.ebay.com/itm/350587388542 $25 + $47
> . One only, Iwaki bellows pump 220VAC.
>
> . http://www.ebay.com/itm/140813153579 $90 + $48
> . Extra high pressure Iwaki pump with magnetic coupling arrangement
> . clearly shown in photos. Comes with useful-looking hose fittings.
>
> There are many more Iwaki magnetically coupled pumps costing more than
> $100. I guess there are lots of now-obsolete photographic processing
> systems being broken up for parts.
>
> - Robin http://www.firstpr.com.au/pcb-diy/
>
>
>
>
>
> [Non-text portions of this message have been removed]
>

Hello Jan,

Very interesting. However, I think that the users in this forum that are interested (including me) in building a spray etching system are more concerned about a real off-the-shelf pump, rather than to experiment with any other methods. The investment in time and money in the construction of a spray etch system may seem confuse for some users, specially if they tend to use the iron-toner method, and only make a few PCBs per month. Some times you need to produce 200, or 400 PCBs per month, and it is a total hassle to work with bubble systems, even if you have 10 or 20 tanks working at the same time. For getting the most advantages of the spray etch system you must use photoresist, and apply the concept of panelizing boards, to load the machine for example with 12x12 inches panels evey time. It makes no sense to build a spray machine for etching 10x10 cms per board.

Regards.

--- In Homebrew_PCBs@yahoogroups.com, Jan Kok <jan.kok.5y@...> wrote:
>
> Something fun to think about or play around with:
>
> FeCl (and probably other etchants as well) is quite conductive.
>
> Now, conductive materials like to stay fixed with respect to magnetic
> fields. See https://www.youtube.com/watch?v=f43fXde2S78 for a
> demonstration. The penny is dragged along by a strong magnet.
>
> See where I'm going with this? A spinning magnet (where the poles
> sweep around) should be able to drag conductive liquids through a tube
> that is wrapped around the spinning magnet.
>
> In fact you don't even need a spinning magnet. You can create a
> rotating magnetic field with electromagnets (for example, remove the
> rotor from a three-phase motor - but use lower voltage when the rotor
> is removed or you'll burn up the windings and/or blow a fuse). You can
> pump conductive liquids with no moving parts at all!
>
> As a bonus, induced current in the liquid would cause heating, so you
> might get your etchant heated as it is being pumped!
>
> Enjoy!
> - Jan
>

Andy, Several years ago I got one from a maker of medical pumps
and the volume was too small. I think a large one could be made
to move a larger volume and that would work. You would need a
much larger hose.

Derward KD5WWI

----- Original Message -----
From: Andrew Volk
To: Homebrew_PCBs@yahoogroups.com
Sent: Wednesday, August 22, 2012 12:27 AM
Subject: RE: [Homebrew_PCBs] Magnetic drive pumps for spray etchers



Has anyone looked at peristaltic pumps? The only thing that comes in
contact to the etchant is the rubber hose that goes through the pump. I got
one off of eBay, as well. The only issue with this kind of pump or the less
expensive pumps in this thread is the volume they can push.

Andy

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Robin Whittle
Sent: Tuesday, August 21, 2012 9:03 PM
To: Homebrew_PCBs@yahoogroups.com
Cc: Ben L
Subject: [Homebrew_PCBs] Magnetic drive pumps for spray etchers

From the thread: "Kepro bench top spray etcher":

An eBay search for:

magnetic pump

produces hundreds of results, some of them for small pumps costing less
than $100. Sorting by "price with shipping" groups similar products
together.

Perhaps not every one of them has a magnetically coupled impeller -
thereby presumably having no metal shaft or seals which could be
attacked the the etchant. Maybe some of these are truly magnetically
coupled, with an impeller magnet totally sealed in plastic, and with
enough pressure to drive spray nozzles.

I think the challenge is to find one or more to make a compact
double-sided spray arrangement, with a smallish amount of etchant.
Prices are USD$ with shipping to Australia.

. http://www.ebay.com/itm/221017721016 $27
. Anti corrosion. 5 litres per minute.

. http://www.ebay.com/itm/221109440478 $20
. Probably too small.

. http://www.ebay.com/itm/270961751604 $25
. Probably too small, but has photos of the magnetic drive system.

. http://www.ebay.com/itm/130481962264 $21
. Another small cheapie - photo shows magnetic drive system.

. http://www.ebay.com/itm/180947111931 $30 + $53 shipping
. Iwaki 100V AC induction motor, uses a capacitor to phase lag the
. second winding. Is the capacitor internal or external?. From a
. photographic processing machine. 6 available.
. At 50Hz, 11 litres/min. Max head 1.5 metres.

. http://www.ebay.com/itm/180955597871 $70 + $80 shipping
. Larger Iwaki pump, one only. 27 litres/min 3.1 metre max head.
. This would be be highly suitable.

. http://www.ebay.com/itm/180954727143 $90 + $135
. Larger Iwaki pump.

. http://www.ebay.com/itm/130681739875 $50 + $51
. Iwaki-Walchem New Old Stock. 220VAC high capacity.

. http://www.ebay.com/itm/130743582615 $83
. High capacity 24 volt with speed control. This is a brushless
. motor, meaning it has electronics to drive three (I guess)
. windings, with a permanent magnet rotor which follows the resultant
. rotating magnetic field. The rotor's shaft is ceramic. So I think
. there is no motor -> magentic coupler, just that the permanent magnet
. rotor and its shaft and bearings can be exposed to liquids without
. being damaged. Many sellers have this item.

The above pumps are centrifugal.

This one is dual interlocking gears, which I think might be better for
producing higher pressures for the restricted flow of a spray system:

. http://www.ebay.com/itm/280929962685? $11
. It is quite small, but if it really is immune to corrosion, then
. two or more could be used, since they are so inexpensive.
. Multiple sellers have the same item.

. http://www.ebay.com/itm/250810139654 $29 + $43
. Another gear pump, with no motor. The pipe fittings could be tricky.
. Up to half a litre per minute, which is rather small. Maximum
. pressure is 75 pounds per square inch, which is very high.

Searching now on:

Iwaki pump

. http://www.ebay.com/itm/350587388542 $25 + $47
. One only, Iwaki bellows pump 220VAC.

. http://www.ebay.com/itm/140813153579 $90 + $48
. Extra high pressure Iwaki pump with magnetic coupling arrangement
. clearly shown in photos. Comes with useful-looking hose fittings.

There are many more Iwaki magnetically coupled pumps costing more than
$100. I guess there are lots of now-obsolete photographic processing
systems being broken up for parts.

- Robin http://www.firstpr.com.au/pcb-diy/

[Non-text portions of this message have been removed]





[Non-text portions of this message have been removed]

I have an etcher suggestion for you.

Many years back I build a spray etcher for a college class, it never really worked all that well. Spray holes would get plugged, never enough pump pressure, plumbing used too much enchants and it was hard finding a pump that would take the hot etchant.

A few years I was doing more and more boards in my garage and got tired of rocking the glass tray back and forth to do the etching. I was looking for a better way to etch, I knew a spray tank was not the answer. Then a friend suggested a splash tank, at first didn't think it would work but it turned out to be the best etcher. At the time I was using heated Ammonium Persulfate and would take up to two 8 x 10 board. With fresh etchant it would etch a single sided board in 20 to 30 seconds but usually it took 1 to 5 minutes.

The tank was built from 3/4" plywood a little over 12" x 12" x 12" with an open top. The interior surfaces were fiber glassed with polyester resin and glass cloth the outside just resin. Makes a nice strong waterproof chemical resistant tank. At each end of the tank there were some guides formed in the sidewalls similar to guides in a card cage. Two board holders, build from pieces of 11" x 11" x 1/4" acrylic slipped down the guides from the top. Boards to be etched were fastened to the face of the holders using rubber suction cups stuck to the holders, the board edges wedged between the upper section of he suction cups. It would hold any shape board or multiple boards and worked very well.

The tank top was three pieces, two removable end covers about 3" x 11" built from acrylic that allowed access to the board holders and a 6" wide center secton from fiber glassed plywood that was screwed down to the sides of the tank. On top of the center section I mounted a 1/16 hp motor salvaged from a squirrel cage blower. A stainless steel shaft extended down to the bottom of the tank into an acrylic block used as a bearing. Near the bottom of the shaft there was a paddle blade sort of like what you see in a blender. The top edge of the tank was formed that no splashing could get out between the covers and the side walls.

In operation the hot persufate was filled just to about the middle of the paddle blade, boards attached to the holders and sliped down into place and the covers installed. When the motor was turned there was a very aggressive splash hitting the boards attached to the holders.

IIRC the bottom of the tank was sloped to the center so as to minimize the volume of etchant, which I think was less than a quart. I posted a sketch in the files section called SplashEtcher.pdf

Craig

Hello Craig,

Remarkable good work you did. Also, thank you for posting your drawing. I am sure that it will be helpful for many users trying to stay away from the bubble or agitated setups.

Again, I will prefer the spray instead of splash, because of the resolutions and detail that you can get. I could buy right now a low-end spray etch tank (Bungard, MegaUK, etc.), but I am not willing to spend so much money for a very simple machine. After many years (decades) inside the PCB industry you see all kind of stuff and you realize that some devices are very simple and are just overpriced. You can build almost any machine for the PCB shop (even multilayer presses, through hole plating systems, etc.), if you are willing to spend time, money, and like to build your own stuff, and of course if you can get all of the necessary and specialized parts.

The design of your splash etch remembers to me a commercial device many years ago, but 4 PCBs could be etched (one-side at at time), located at every side of the container. It was the same function as your unit, using the paddles, as you did.

Regards.

--- In Homebrew_PCBs@yahoogroups.com, "designer_craig" <cs6061@...> wrote:
>
> I have an etcher suggestion for you.
>
> Many years back I build a spray etcher for a college class, it never really worked all that well. Spray holes would get plugged, never enough pump pressure, plumbing used too much enchants and it was hard finding a pump that would take the hot etchant.
>
> A few years I was doing more and more boards in my garage and got tired of rocking the glass tray back and forth to do the etching. I was looking for a better way to etch, I knew a spray tank was not the answer. Then a friend suggested a splash tank, at first didn't think it would work but it turned out to be the best etcher. At the time I was using heated Ammonium Persulfate and would take up to two 8 x 10 board. With fresh etchant it would etch a single sided board in 20 to 30 seconds but usually it took 1 to 5 minutes.
>
> The tank was built from 3/4" plywood a little over 12" x 12" x 12" with an open top. The interior surfaces were fiber glassed with polyester resin and glass cloth the outside just resin. Makes a nice strong waterproof chemical resistant tank. At each end of the tank there were some guides formed in the sidewalls similar to guides in a card cage. Two board holders, build from pieces of 11" x 11" x 1/4" acrylic slipped down the guides from the top. Boards to be etched were fastened to the face of the holders using rubber suction cups stuck to the holders, the board edges wedged between the upper section of he suction cups. It would hold any shape board or multiple boards and worked very well.
>
> The tank top was three pieces, two removable end covers about 3" x 11" built from acrylic that allowed access to the board holders and a 6" wide center secton from fiber glassed plywood that was screwed down to the sides of the tank. On top of the center section I mounted a 1/16 hp motor salvaged from a squirrel cage blower. A stainless steel shaft extended down to the bottom of the tank into an acrylic block used as a bearing. Near the bottom of the shaft there was a paddle blade sort of like what you see in a blender. The top edge of the tank was formed that no splashing could get out between the covers and the side walls.
>
> In operation the hot persufate was filled just to about the middle of the paddle blade, boards attached to the holders and sliped down into place and the covers installed. When the motor was turned there was a very aggressive splash hitting the boards attached to the holders.
>
> IIRC the bottom of the tank was sloped to the center so as to minimize the volume of etchant, which I think was less than a quart. I posted a sketch in the files section called SplashEtcher.pdf
>
> Craig
>

> Robin Whittle wrote:
>
> From the thread: "Kepro bench top spray etcher":
>
> An eBay search for:
>
> magnetic pump
>
> produces hundreds of results, some of them for
> small pumps costing less than $100. Sorting
> by "price with shipping" groups similar products
> together.
>
> <SNIP - all th details on pumps and prices>

Quite coincidental timing here really.

I have just a few weeks ago finished the rotary
spray etcher I started in 2006 and am almost done
with my photo laser plotter started at the same
time. (I'm getting better only 5 years behind
schedule)

I am about to publish the details of both. So
you might want to hold of spending $100s on pumps
for a few weeks.

The whole spray etcher can be built sub $30 if
you have a table saw ($40-$50 ish without)

It has a couple of sneaky tricks to sort out the
uniformity/banding issues Stefan Trethan had
when trying to build his (ref 1).

I built mine to accommodate 75x150mm boards. It
could scale up a bit. But if you where planing
doing big boards, I would opt for following
Adam Seychells design (ref 2).

BTW, does anyone have an archive of Adams work
aside from the CuCl bit?


1.
http://tech.groups.yahoo.com/group/Homebrew_PCBs/message/8579

2.
http://web.archive.org/web/20090103105924/http://members.optusnet.com.au/~eseychell/PCB/SprayEtcher/index.html

I have one other idea I want to try some day. When I clean paint rollers after painting, I wash them the best I can then take them out side and hit the roller with the garden hose. As the roller spins up it emits a nice fine spray from the entire length. Was wondering if one could mechanically drive something similar to a roller that had etchant in the center with a series of small diameter holes to keep the surface wet. The spinning surface would sling off the etchant at the board.

Craig

--- In Homebrew_PCBs@yahoogroups.com, "jcarlosmor" <jcarlosmor@...> wrote:
>
>
> Hello Craig,
>
> Remarkable good work you did. Also, thank you for posting your drawing. I am sure that it will be helpful for many users trying to stay away from the bubble or agitated setups.
>
> Again, I will prefer the spray instead of splash, because of the resolutions and detail that you can get. I could buy right now a low-end spray etch tank (Bungard, MegaUK, etc.), but I am not willing to spend so much money for a very simple machine. After many years (decades) inside the PCB industry you see all kind of stuff and you realize that some devices are very simple and are just overpriced. You can build almost any machine for the PCB shop (even multilayer presses, through hole plating systems, etc.), if you are willing to spend time, money, and like to build your own stuff, and of course if you can get all of the necessary and specialized parts.
>
> The design of your splash etch remembers to me a commercial device many years ago, but 4 PCBs could be etched (one-side at at time), located at every side of the container. It was the same function as your unit, using the paddles, as you did.
>
> Regards.
>
>
>
>
>
>
>
> --- In Homebrew_PCBs@yahoogroups.com, "designer_craig" <cs6061@> wrote:
> >
> > I have an etcher suggestion for you.
> >
> > Many years back I build a spray etcher for a college class, it never really worked all that well. Spray holes would get plugged, never enough pump pressure, plumbing used too much enchants and it was hard finding a pump that would take the hot etchant.
> >
> > A few years I was doing more and more boards in my garage and got tired of rocking the glass tray back and forth to do the etching. I was looking for a better way to etch, I knew a spray tank was not the answer. Then a friend suggested a splash tank, at first didn't think it would work but it turned out to be the best etcher. At the time I was using heated Ammonium Persulfate and would take up to two 8 x 10 board. With fresh etchant it would etch a single sided board in 20 to 30 seconds but usually it took 1 to 5 minutes.
> >
> > The tank was built from 3/4" plywood a little over 12" x 12" x 12" with an open top. The interior surfaces were fiber glassed with polyester resin and glass cloth the outside just resin. Makes a nice strong waterproof chemical resistant tank. At each end of the tank there were some guides formed in the sidewalls similar to guides in a card cage. Two board holders, build from pieces of 11" x 11" x 1/4" acrylic slipped down the guides from the top. Boards to be etched were fastened to the face of the holders using rubber suction cups stuck to the holders, the board edges wedged between the upper section of he suction cups. It would hold any shape board or multiple boards and worked very well.
> >
> > The tank top was three pieces, two removable end covers about 3" x 11" built from acrylic that allowed access to the board holders and a 6" wide center secton from fiber glassed plywood that was screwed down to the sides of the tank. On top of the center section I mounted a 1/16 hp motor salvaged from a squirrel cage blower. A stainless steel shaft extended down to the bottom of the tank into an acrylic block used as a bearing. Near the bottom of the shaft there was a paddle blade sort of like what you see in a blender. The top edge of the tank was formed that no splashing could get out between the covers and the side walls.
> >
> > In operation the hot persufate was filled just to about the middle of the paddle blade, boards attached to the holders and sliped down into place and the covers installed. When the motor was turned there was a very aggressive splash hitting the boards attached to the holders.
> >
> > IIRC the bottom of the tank was sloped to the center so as to minimize the volume of etchant, which I think was less than a quart. I posted a sketch in the files section called SplashEtcher.pdf
> >
> > Craig
> >
>

Maybe a shurflo diaphragm pump?

--- In Homebrew_PCBs@yahoogroups.com, "twb8899" <twb8899@...> wrote:
>
> The spray manifold on the Kepro etchers are nothing more than two pieces of 1/2" CPVC pipe with a pattern of small holes spaced out over a 5 or 6 inch length.
>
> The drilled holes are about 1/16" and drilled in a pattern something like this:
>
>
> -------------------------------------------
> O O O O O O
> O O O O O
> O O O O O O
> -------------------------------------------
>
>
> The manifold is made from a "T" fitting with two pieces of drilled pipe plugged into each side for an overall length of about 12". Nothing is glued except for the end caps. The pieces are press fit together so you can adjust the spray pattern. The spray manifold is spaced about 3" from the board surface.
>
> About half way between the spray manifold and the board is a piece of fiberglass screen to break up the spray pattern for better distribution over the entire board surface. The screen has a heavy strip of PVC plastic glued to the bottom to keep it in place when the pumps are spraying.
>
> The spray manifold is positioned closer to the top of the board so the etchant can run across the board surface as it falls back to the sump. These etching machines work pretty good and are simple to make. The main problem with the Kepro units was pump failure. Substituting a better pump is a wise thing to do or find a better way to seal the pump shaft and bearings from etchant fumes.
>
> Tom
>
>
> --- In Homebrew_PCBs@yahoogroups.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, "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
> > >
> >
>