Homebrew PCBs

Guys,

things are looking bad.

No matter what i do i just can't get a somewhat uniform spray pattern.
I have tried many different hole arrangements and inlet plates, and while  
the amount of liquid seems to be enough it does never produce a somewhat  
even pattern. It behaves totally unexpected at times, like spraying from  
the topmost hole only the lower ones beeing dry (?????). My guess is it is  
all because things are out-of-round by a tiny amount, especially when  
rotatig. Sometimes it oscillates "pulsing" the spray pressure, at other  
times it doesn't. It is running way too loud and i'm sick of seeing it to  
be honest. I do not see a point where the uniformity will be better than  
with a bubbler in a somewhat reasonable timeframe and the eventual  
increase in etching speed is long eaten up by construction time.
I must draw a line somewhere how far i'm prepared to take this, and i have  
reached it i think.
I would much rather spend my time actually making PCBs (especially  
following up on the silicone paper).

My plan now is to lay this project to rest, and use the existing materials  
to build a bigger, better bubble-tank with all the flaws of the old one  
corrected. The slightly uneven etch and longer times are something i must  
live with i fear.


Thanks for all the input, but this doesn't work for me.
The construction is no problem, the flow and pressure seems no problem,  
but uniformity is a much bigger problem than i thought.


(By the way, i have found acrylic sealant to be a reasonably good adhesive  
for polycarbonate/lexan, although i have in the end not used the lexan)

ST

Stefan Trethan wrote:

> rotatig. Sometimes it oscillates "pulsing" the spray pressure, at other  
> times it doesn't. It is running way too loud and i'm sick of seeing it to  
> be honest. I do not see a point where the uniformity will be better than  
> with a bubbler in a somewhat reasonable timeframe and the eventual  
> increase in etching speed is long eaten up by construction time.

   Hadn't been following lately, sure there isn't more to the commercial 
systems?  What's the diameter of the tube?  Even 10K RPM isn't much if the 
diameter is small.  And water has a strong adhesion force, it could be very 
important that the tube is the right type of plastic so it's not sticking as 
it's coming out of the holes.  Still seems it would be problematic.  Also is it 
pressurized from the other end in commercial unit?  Etchant in a small closed 
tank, and pressurized with say a $10 car tire pump, basically a lower pressure 
pressure washer.

> I must draw a line somewhere how far i'm prepared to take this, and i have  
> reached it i think.
> I would much rather spend my time actually making PCBs (especially  
> following up on the silicone paper).
> 
> My plan now is to lay this project to rest, and use the existing materials  
> to build a bigger, better bubble-tank with all the flaws of the old one  
> corrected. The slightly uneven etch and longer times are something i must  
> live with i fear.
> 

   How are your bubble etches uneven?  More finer bubbles should make things 
fairly even in a local sense, if it's more etched at the top than bottom or vise 
versa then use more bubbles and slope the side of the tank away from or toward 
the board to even things out.

   Don't need one myself, but I'm thinking one of the long fine bubble aerator 
tubes for fish tanks and a sloped tank side to even things out against a 
vertical board should come out fairly even.  But bubbles do only travel one 
direction.


   Not sure that's even needed.  Use a rigid frame for the board, on a floating 
suspension over the tank.  Stick a medium sized massager vibrator motor on the 
frame and see if that doesn't work.  May need a small amount of pumped 
circulation for best effect, but a vibrating board should do fairly well just by 
itself.

Alan

On Fri, 15 Apr 2005 16:46:42 -0400, Alan King <alan@...> wrote:

>
>    How are your bubble etches uneven?  More finer bubbles should make  
> things
> fairly even in a local sense, if it's more etched at the top than bottom  
> or vise
> versa then use more bubbles and slope the side of the tank away from or  
> toward
> the board to even things out.

It is faster at the bottom, where the bubbles hit.
Sloped sides sound interesting, any idea how much?

I had streaks from the bubbler-holes, but i'm gonna fight that with a  
porous bubbler.


>   Not sure that's even needed.  Use a rigid frame for the board, on a  
> floating
> suspension over the tank.  Stick a medium sized massager vibrator motor  
> on the
> frame and see if that doesn't work.  May need a small amount of pumped
> circulation for best effect, but a vibrating board should do fairly well  
> just by
> itself.
> Alan


Don't like moving the board much 'cause it requires a pretty firm hold on  
the board. I have a rather nice board holder
design that clamps the board without needing to wash anything or use  
gloves etc., the downside is it can't be super-strong hold.



ST

Stefan Trethan wrote:

> On Fri, 15 Apr 2005 16:46:42 -0400, Alan King <alan@...> wrote:
>
> 
> It is faster at the bottom, where the bubbles hit.
> Sloped sides sound interesting, any idea how much?
> 
> I had streaks from the bubbler-holes, but i'm gonna fight that with a  
> porous bubbler.
> 

   Nope, would take some tests.  Just a flat plate in the bottom corner leaning 
in at an angle should give an idea.  Just occurred to me off the top of my head 
that the bubbles are giving less action from spreading out horizontally and 
joining together as they rise when I read your last message.  A wedge pushing 
them back towards the board should do a lot for it.

>
> Don't like moving the board much 'cause it requires a pretty firm hold on  
> the board. I have a rather nice board holder
> design that clamps the board without needing to wash anything or use  
> gloves etc., the downside is it can't be super-strong hold.
> 
> 

   Well I was thinking clamp the board through the thickness on either side.. 
Most important is if it etches well, an easy and suitable board holder can 
always be figured out later.  I like the idea and have a vibrating point etcher 
for marking metal, may have to try it out along with the silicone caulked paper. 
  I've got a few small test boards to do in the next few days anyways.  Last few 
prints have been light, wondering if my printer is low on toner though it's 
about time..

   Should have occurred to me earlier, it's the same idea behind a parts 
cleaner.  A $100 parts cleaner might do an excellent job for both cleaning and 
etching with one piece of equipment.  So many are only watch sized now

Alan

On Fri, 15 Apr 2005 18:09:02 -0400, Alan King <alan@...> wrote:

>
>    Nope, would take some tests.  Just a flat plate in the bottom corner  
> leaning
> in at an angle should give an idea.  Just occurred to me off the top of  
> my head
> that the bubbles are giving less action from spreading out horizontally  
> and
> joining together as they rise when I read your last message.  A wedge  
> pushing
> them back towards the board should do a lot for it.


Well, while it sounds like a good idea, it needn't necessarily really work  
;-) .

I think the bubbles will not stay attached to the board, unless you can  
get that wedge very, very close.
Which might actually work, like making the gap smaller than bubble  
diameter. the flow of etchant is pretty high from the bubbles so it should  
stay fresh.


BUT this needs experimenting, and i can not just make the walls of the new  
tank sloped a guessed angle.
I think it is easier to make the tank straight and insert plastic plates  
at a later time. It could be like a upside-down funnel shape at the bottom  
of the board, herding all bubbles through a small gap between pcb and the  
bubble-guide.

A possible problem i see with this is that one would need a very precise  
board holder, if the board is not centered precisely it will cause trouble.

ST

Stefan Trethan wrote:
> On Fri, 15 Apr 2005 18:09:02 -0400, Alan King <alan@...> wrote:
> 
> 
>>   Nope, would take some tests.  Just a flat plate in the bottom corner  
>>leaning
>>in at an angle should give an idea.  Just occurred to me off the top of  
>>my head
>>that the bubbles are giving less action from spreading out horizontally  
>>and
>>joining together as they rise when I read your last message.  A wedge  
>>pushing
>>them back towards the board should do a lot for it.
> 
> 
> 
> Well, while it sounds like a good idea, it needn't necessarily really work  
> ;-) .
>

   LOL heard that!


> I think the bubbles will not stay attached to the board, unless you can  
> get that wedge very, very close.
> Which might actually work, like making the gap smaller than bubble  
> diameter. the flow of etchant is pretty high from the bubbles so it should  
> stay fresh.
> 

   Well I was thinking make more bubbles.  If you have enough bubbles 1/4" or 
1/2" shouldn't be a problem, more like a circulating foam..

> 
> BUT this needs experimenting, and i can not just make the walls of the new  
> tank sloped a guessed angle.
> I think it is easier to make the tank straight and insert plastic plates  
> at a later time. It could be like a upside-down funnel shape at the bottom  
> of the board, herding all bubbles through a small gap between pcb and the  
> bubble-guide.
> 
> A possible problem i see with this is that one would need a very precise  
> board holder, if the board is not centered precisely it will cause trouble.
> 

   Yep test plates in a normal tank to figure the angle.  May be easier to have 
a straight tank and insert type plates anyway..

   If you've got 2 bubble tubes one on each side with enough bubbles, and enough 
slope forcing the bubbles in, the board should stay fairly centered as long as 
about the same amount of bubbles are on each side I think..

   Hmm two bubble tubes touching and the board sitting in the groove between 
them should do it.  Bottom 1/4" or 1/2" may over etch but that's a small price 
to pay for simplicity.

   Hard to keep the tubes aerating evenly in a fishtank but I think nothing will 
grow in etchant.  Still may clog over time but I think they're cheap..

Alan

Hello,

Can I ask a really dumb question?

When I visit my board house (they're local and let me "tour" as I 
wish; a 900x certified facility) I see ALL their plating and etching 
baths using vertical board holders closely spaced in large tanks. 

No slanted walls, No bubbles. But here IS good recirculation of the 
etchant. (They do acid etching, AIRC)

If it works for them; why doesn't it work for us?

Ballendo

P.S. A buddy bought a commercial spray etcher from a closing low 
volume PCB fab house (They mostly stuffed boards, so were not really 
a PCB mfr. Had the spray etcher to be "complete" I guess.) 

Nothing special about it. Again boards/panels held vertically, with 
SS spray jets on each plexiglas side--might have been polycarb 
instead of acrylic? It WAS clear--and about 2' high by 3 feet wide 
and about 4-6 inches thick The spray nozzles were on about 8 inch 
centers The spray form was a flat cone, and they overlapped about 1/3 
cone. (So there was a spray line about every 2-2/3 inches)

I'm pretty sure it had a back and forth motion to the board holder; 
kinda like Markus Zingg's THP line setup, only 90 degrees turned Like 
duck decoys at an amusement park shooting range.

The etchant was clear (AP?)

Worked like a charm; but took up too much space for him so he sold it.

So the second question is, since we know spray etchers work, why are 
they so hard to duplicate?

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
> On Fri, 15 Apr 2005 18:09:02 -0400, Alan King <alan@n...> wrote:
> 
> >
> >    Nope, would take some tests.  Just a flat plate in the bottom 
corner  
> > leaning
> > in at an angle should give an idea.  Just occurred to me off the 
top of  
> > my head
> > that the bubbles are giving less action from spreading out 
horizontally  
> > and
> > joining together as they rise when I read your last message.  A 
wedge  
> > pushing
> > them back towards the board should do a lot for it.
> 
> 
> Well, while it sounds like a good idea, it needn't necessarily 
really work  
> ;-) .
> 
> I think the bubbles will not stay attached to the board, unless you 
can  
> get that wedge very, very close.
> Which might actually work, like making the gap smaller than bubble  
> diameter. the flow of etchant is pretty high from the bubbles so it 
should  
> stay fresh.
> 
> 
> BUT this needs experimenting, and i can not just make the walls of 
the new  
> tank sloped a guessed angle.
> I think it is easier to make the tank straight and insert plastic 
plates  
> at a later time. It could be like a upside-down funnel shape at the 
bottom  
> of the board, herding all bubbles through a small gap between pcb 
and the  
> bubble-guide.
> 
> A possible problem i see with this is that one would need a very 
precise  
> board holder, if the board is not centered precisely it will cause 
trouble.
> 
> ST

On Sat, 16 Apr 2005 08:27:21 -0000, ballendo <ballendo@...> wrote:

>
> Hello,
> Can I ask a really dumb question?
> When I visit my board house (they're local and let me "tour" as I
> wish; a 900x certified facility) I see ALL their plating and etching
> baths using vertical board holders closely spaced in large tanks.
> No slanted walls, No bubbles. But here IS good recirculation of the
> etchant. (They do acid etching, AIRC)
> If it works for them; why doesn't it work for us?
> Ballendo


It does work for us, however if i have uneven etch that limits resolution  
and min. track width as the faster portions get etched more. True i do not  
really currently need more resolution than i can get, but i still like to  
solve problems.


> P.S. A buddy bought a commercial spray etcher from a closing low
> volume PCB fab house (They mostly stuffed boards, so were not really
> a PCB mfr. Had the spray etcher to be "complete" I guess.)
> Nothing special about it. Again boards/panels held vertically, with
> SS spray jets on each plexiglas side--might have been polycarb
> instead of acrylic? It WAS clear--and about 2' high by 3 feet wide
> and about 4-6 inches thick The spray nozzles were on about 8 inch
> centers The spray form was a flat cone, and they overlapped about 1/3
> cone. (So there was a spray line about every 2-2/3 inches)
> I'm pretty sure it had a back and forth motion to the board holder;
> kinda like Markus Zingg's THP line setup, only 90 degrees turned Like
> duck decoys at an amusement park shooting range.
> The etchant was clear (AP?)
> Worked like a charm; but took up too much space for him so he sold it.
> So the second question is, since we know spray etchers work, why are
> they so hard to duplicate?

Because those manufacturers spend a lot of money and time to develop these  
machines. I have no doubt it can be done (some have), but the simple and  
cheap solution i had aimed for didn't work out for me.

ST

On Fri, 15 Apr 2005 18:33:54 -0400, Alan King <alan@...> wrote:

>
>    Well I was thinking make more bubbles.  If you have enough bubbles  
> 1/4" or
> 1/2" shouldn't be a problem, more like a circulating foam..
>

Well, too much foam will not be good, if it overflows the container ;-)
So far i have noticed foaming is not a problem, the CuCl readily releases  
the air and one can safely assume the increase in volume is only dependent  
on air flow. I don't know if other etchants foam more, FeCl is used in  
foam etchers but i dunno if there is a foaming agent used.
The whole thing meaning, in CuCl the foam doesn't circulate because the  
bubbles only go up, but it isn't a problem as with more air the same  
effect can be achieved.

>   Yep test plates in a normal tank to figure the angle.  May be easier  
> to have
> a straight tank and insert type plates anyway..
>   If you've got 2 bubble tubes one on each side with enough bubbles, and  
> enough
> slope forcing the bubbles in, the board should stay fairly centered as  
> long as
> about the same amount of bubbles are on each side I think..
>   Hmm two bubble tubes touching and the board sitting in the groove  
> between
> them should do it.  Bottom 1/4" or 1/2" may over etch but that's a small  
> price
> to pay for simplicity.
>   Hard to keep the tubes aerating evenly in a fishtank but I think  
> nothing will
> grow in etchant.  Still may clog over time but I think they're cheap..
> Alan


What i do not know is if bigger or smaller bubbles are better.  
think/tinker is sure big bubbles are good, 'cause small bubbles are not  
causing enough scrubbing action. OTOH i have tried big bubbles, and it is  
hard to get them evenly distributed over the board and they tend to form  
vertical streaks on the board that are 2 to 3 times faster etched than  
other places. I will rather have smaller bubbles, and slightly longer  
etch, if it is even.

ST

Stefan Trethan wrote:
> The whole thing meaning, in CuCl the foam doesn't circulate because the  
> bubbles only go up, but it isn't a problem as with more air the same  
> effect can be achieved.

   It'll still be making circulation, but maybe not as good a rate..



> What i do not know is if bigger or smaller bubbles are better.  
> think/tinker is sure big bubbles are good, 'cause small bubbles are not  
> causing enough scrubbing action. OTOH i have tried big bubbles, and it is  
> hard to get them evenly distributed over the board and they tend to form  
> vertical streaks on the board that are 2 to 3 times faster etched than  
> other places. I will rather have smaller bubbles, and slightly longer  
> etch, if it is even.
> 


   Unconstrained, bigger probably is better, causing more direct action in the 
liquid as the bubble moves up.  But with more smaller bubbles and being kept 
toward the board I doubt you'd see much difference, and of course the smaller 
should be more even.  There are 8-10 inch long 1/4 inch round green tube fish 
aerators that put out lots of bubbles, that's what I'm thinking of.  Hard to 
find a pic, don't know the brand name and you get too much other stuff on a net 
search.  May just get a couple for trying later if I go out and send a picture.

Alan

On Sat, 16 Apr 2005 14:27:42 -0400, Alan King <alan@...> wrote:

>
>    Unconstrained, bigger probably is better, causing more direct action  
> in the
> liquid as the bubble moves up.  But with more smaller bubbles and being  
> kept
> toward the board I doubt you'd see much difference, and of course the  
> smaller
> should be more even.  There are 8-10 inch long 1/4 inch round green tube  
> fish
> aerators that put out lots of bubbles, that's what I'm thinking of.   
> Hard to
> find a pic, don't know the brand name and you get too much other stuff  
> on a net
> search.  May just get a couple for trying later if I go out and send a  
> picture.
> Alan


I've found such fish bubblers on ebay, despite warnings they fall apart in  
cucl a small one i tested didn't.
The ones on ebay are 30cm long green ones and are only 2eur each. will get  
'em.

I see no way getting big bubbles that are not in streaks, one would need a  
mighty pump to have holes so closely spaced with large diameter.

ST

ballendo wrote:
> 
> Hello,
> 
> Can I ask a really dumb question?
> 
> When I visit my board house (they're local and let me "tour" as I 
> wish; a 900x certified facility) I see ALL their plating and etching 
> baths using vertical board holders closely spaced in large tanks. 
> 
> No slanted walls, No bubbles. But here IS good recirculation of the 
> etchant. (They do acid etching, AIRC)
> 
> If it works for them; why doesn't it work for us?
> 

   How many tens of thousands of dollars did they pay for their equipment?  How 
much does it cost per month to maintain?

   Do you build a giant conveyor oven to cook a 50 cent snack?  That is what the 
big food making companies use, why are you so silly and still using an old 
fashion oven?  What makes sense on a commercial scale is almost never the right 
answer on an individual one.  Even when it is it's not because 'that's what they 
do' but because it's the right thing to do even on a small scale.

> 
> Nothing special about it. Again boards/panels held vertically, with 

   LOL, says you, maybe.  How many years did it take them to evolve it into what 
you see?  How much money did it take to evolve it into something good enough to 
fool you into thinking it's simple?  Not that it's impossible to do, but you 
don't appear to have asked yourself any questions about time, effort, and 
development cost.  Is it really easy, or does it just look easy to you because 
you have no idea of how difficult or easy it is?  Of course it seems easy, 
seeing a whole made unit.  But actually you have no real idea if it's easy or 
not from that.

   See it all the time in RC helis.  Unbelievable how many people throw away a 
grand or two because it looks easy, without first stopping to think that maybe 
it's not as easy as someone with years of practice makes it look..

   Slanted walls, bubbles?  Those are something especially hard or unusual?  You 
are worried about some trivial things I think..  Just try building that rotating 
tube yourself for educational purposes and see how easy it is.

   Fact is that a slanted plate bubble tank, brought up to roughly as effective, 
and being several times easier to build, would be a far better, higher end 
result technology item than a spray system.  You're just not recognizing a 
potentially superior system when you're reading about it.  Actively pumped can 
always be faster, but if the speed margin isn't 4x or better the complexity will 
never pay off for a home user.  Even that likely wouldn't be enough, do most 
people care if the board etches in 10 minutes or 2 minutes, long as it's not a 
half hour?

Alan

In a message dated 4/16/2005 2:43:25 P.M. Eastern Daylight Time,  
stefan_trethan@... writes:

I see no  way getting big bubbles that are not in streaks, one would need a   
mighty pump to have holes so closely spaced with large  diameter.

ST




What about slowly rotating the pipe with the holes in  it? Sort of like a 
player piano. Drill the holes so as it rotates it covers  every bit with bubbles?
 
Ray Russell
NMRA-40609
General Contractor
Norfolk &  Western Railroad
Pocahontas Division
Circa 1958
Visit The "NEW"  Pocahontas Website at:_ Click here: N  & W Pocahontas  
Division_ (http://members.aol.com/rruss45826/public_html/index.html) 
http://members.aol.com/rruss45826/public_html/index.html

OR_ Click here:  Pocahontas Home_ 
(http://milliron.home.sprynet.com/Pocahontas/Pocahontas1.htm)  
For the old website!  
http://milliron.home.sprynet.com/Pocahontas/Pocahontas1.htm


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

On Sun, 17 Apr 2005 00:19:35 EDT, <rruss45826@...> wrote:

>
> What about slowly rotating the pipe with the holes in  it? Sort of like a
> player piano. Drill the holes so as it rotates it covers  every bit with  
> bubbles?


That might actually help, but it seems complicated to me. one would need  
to drive that pipe a foot down in very agressive etchant.
I do not think it is an easy solution, moving the board or hose linear  
could even be easier.


Thanks for the idea anyway.

ST

Stefan Trethan wrote:
> On Sat, 16 Apr 2005 14:27:42 -0400, Alan King <alan@...> wrote:
> 

> 
> I've found such fish bubblers on ebay, despite warnings they fall apart in  
> cucl a small one i tested didn't.
> The ones on ebay are 30cm long green ones and are only 2eur each. will get  
> 'em.
> 
> I see no way getting big bubbles that are not in streaks, one would need a  
> mighty pump to have holes so closely spaced with large diameter.
> 

   Yep I'd say small to medium at most.  I was thinking about picking up one of 
the tubes, but then it hit me duh I have a drilling machine and .010" drills, 
probably better to take something like an IC tube and make my own tests.  I 
could easily put in 1000 discrete holes at patterned locations.  Likely need 
more at the edges since they'll be spreading into areas with no bubbles.

   Actually the IC tube for .3" DIPs may be a good thing.  Turned upside down it 
has a groove between the two humps for the DIP leads.  May lose the bottom 
1/4"-1/2" but that'd be ok by me for an all in one solution..

   Might still need to have the tube lower to give it time to form a good stream 
of bubbles, I may do a few tests soon.  Just ran back into my aerator pump so I 
have the testing materials at hand.

Alan

On Sun, 17 Apr 2005 18:09:20 -0400, Alan King <alan@...> wrote:

>
>    Yep I'd say small to medium at most.  I was thinking about picking up  
> one of
> the tubes, but then it hit me duh I have a drilling machine and .010"  
> drills,
> probably better to take something like an IC tube and make my own  
> tests.  I
> could easily put in 1000 discrete holes at patterned locations.  Likely  
> need
> more at the edges since they'll be spreading into areas with no bubbles.
>   Actually the IC tube for .3" DIPs may be a good thing.  Turned upside  
> down it
> has a groove between the two humps for the DIP leads.  May lose the  
> bottom
> 1/4"-1/2" but that'd be ok by me for an all in one solution..
>   Might still need to have the tube lower to give it time to form a good  
> stream
> of bubbles, I may do a few tests soon.  Just ran back into my aerator  
> pump so I
> have the testing materials at hand.
> Alan


ok, thanks, let me know the findings. the IC tube is a good idea.
Now if i only had a x/y table or a cnc to get those holes in with some  
accuracy...

ST

Hello Stefan,

  Monday, April 18, 2005, 12:15:25 AM, you wrote:



ST> ok, thanks, let me know the findings. the IC tube is a good idea.
ST> Now if i only had a x/y table or a cnc to get those holes in with some
ST> accuracy...

ST> ST


  Let me put my �0.02 onto this

  There  is a possibility to find the flexible aerator for fish tanks.
  I  do  use  one in my etching tank. it makes very small bubbles, and
  has the led rod inside for keeping it at the bottom of the tank. The
  only  thing  that  you  should  do  is  to  take it appart, use some
  lacquer/paint  to chemically insulate the led rod, assemble and glue
  it  together and you are on. It does not preoduce any streaks on the
  pcb during etching.

  Will put some pictures of this setup somwhere during next week.

-- 
 Sincerely,
����``````````````````````````````````````````````````````����
ZAS ElMed                        | mailto:zasto@...
                                 | http://www.zas-elmed.co.yu
                                 | Tel/Fax: +381 11 344-0748
                                 | 
 Zoran A. Scepanovic             |     Mob: +381 63 609-993
���,����������������������������������������,�������������,���

*********
Oops.  My brain just hit a bad sector.
*********


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

On Mon, 18 Apr 2005 09:19:59 +0200, Zoran A. Scepanovic <zasto@...>  
wrote:

>
>   Let me put my �0.02 onto this
>  There  is a possibility to find the flexible aerator for fish tanks.
>   I  do  use  one in my etching tank. it makes very small bubbles, and
>   has the led rod inside for keeping it at the bottom of the tank. The
>   only  thing  that  you  should  do  is  to  take it appart, use some
>   lacquer/paint  to chemically insulate the led rod, assemble and glue
>   it  together and you are on. It does not preoduce any streaks on the
>   pcb during etching.
>  Will put some pictures of this setup somwhere during next week.


I have seen the flexible hose and i know a german supplier of etching  
tanks uses it.
However i did not know how many holes are in there so dared not buy it.
I would most appreciate a picture of the hose in action.


ST