Homebrew_PCBs

Hi guys,

Went out to etch a board this morning only to find my tank empty -
luckily I store it inside a bucket so all was well. The Ferric
Chloride siphoned out through the air hose inlet which passes through
a hole in the side of the tank. Aside from it completely disolving
the brass fitting which connects to my compressor, nothing else bad
happened.

Just make sure to clamp the hose shut and to store your etching tank
inside another vesel to capture the fluids should the main tank have
problems.

Chris

On Mon, 11 Sep 2006 16:04:59 +0200, lcdpublishing
<lcdpublishing@...> wrote:

> Hi guys,
> Went out to etch a board this morning only to find my tank empty -
> luckily I store it inside a bucket so all was well. The Ferric
> Chloride siphoned out through the air hose inlet which passes through
> a hole in the side of the tank. Aside from it completely disolving
> the brass fitting which connects to my compressor, nothing else bad
> happened.
> Just make sure to clamp the hose shut and to store your etching tank
> inside another vesel to capture the fluids should the main tank have
> problems.
> Chris

Indeed! I had a similar situation, twice ;-)


Does the hose leave the tank below or above the etchant level?


If you have a second container where it sits in, it is annoying, but
imagine what it would be if there was no second container ;-)

For the air hose you could also try a no-return valve like sold for fish
tanks to prevent exactly that problem of water flowing back out.


ST

My hose comes out of the tank above water level, however, I just
coil it up and let it lay in the bucket around the tank. Something
must have got it going to siphon it all out, not sure what or why,
but lesson learned!

I have one of those valves around here somewhere and am going to
have to find it and install it. I would much rather be safe than to
have that kind of mess again.

Apparently, based on the longer etch times, the brass
fitting "consumed" a lot of the strength of the Ferric Chloride as
it melted away into never-never-land :-( I guess I will have to
order up some more powder and make a new batch soon.

Chris



--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@...> wrote:

>
> On Mon, 11 Sep 2006 16:04:59 +0200, lcdpublishing
> <lcdpublishing@...> wrote:
>
> > Hi guys,
> > Went out to etch a board this morning only to find my tank

empty -

> > luckily I store it inside a bucket so all was well. The Ferric
> > Chloride siphoned out through the air hose inlet which passes

through

> > a hole in the side of the tank. Aside from it completely

disolving

> > the brass fitting which connects to my compressor, nothing else

bad

> > happened.
> > Just make sure to clamp the hose shut and to store your etching

tank

> > inside another vesel to capture the fluids should the main tank

have

> > problems.
> > Chris
>
>
> Indeed! I had a similar situation, twice ;-)
>
>
> Does the hose leave the tank below or above the etchant level?
>
>
> If you have a second container where it sits in, it is annoying,

but

> imagine what it would be if there was no second container ;-)
>
> For the air hose you could also try a no-return valve like sold

for fish

> tanks to prevent exactly that problem of water flowing back out.
>
>
> ST
>

On Mon, 11 Sep 2006 18:31:44 +0200, lcdpublishing
<lcdpublishing@...> wrote:

> My hose comes out of the tank above water level, however, I just
> coil it up and let it lay in the bucket around the tank. Something
> must have got it going to siphon it all out, not sure what or why,
> but lesson learned!
> I have one of those valves around here somewhere and am going to
> have to find it and install it. I would much rather be safe than to
> have that kind of mess again.
> Apparently, based on the longer etch times, the brass
> fitting "consumed" a lot of the strength of the Ferric Chloride as
> it melted away into never-never-land :-( I guess I will have to
> order up some more powder and make a new batch soon.
> Chris

hmm, i have the hose above etchant level as well, and thought myself
rather safe due to that. Maybe i should hang the pump up over the tank so
that the hose goes straight up....

If you wanted that siphon to get going without intervention you could
probably never recreate the effect on purpose.
Do you have the tank covered tightly? If so i could imagine changes in
temperature to start it off by pushing etchant up the tube.

ST

2006/9/11, lcdpublishing <lcdpublishing@...>:

>
> ...
>
> Apparently, based on the longer etch times, the brass
> fitting "consumed" a lot of the strength of the Ferric Chloride as
> it melted away into never-never-land :-( I guess I will have to
> order up some more powder and make a new batch soon.
>
> Chris
>
> -
>






>
>

Hi Chris

Before you spend your money go to the supermarket, buy
a bottle of Muriatic Acid (Hidrochloric Acid, HCL,
http://en.wikipedia.org/wiki/Hydrochloric_acid ), plus a bottle
of Hydrogen Peroxide (H2O2,
http://en.wikipedia.org/wiki/Hydrogen_peroxide )

And, carefully melt them with your FeCl. First the HCL and later the H2O2

http://en.wikipedia.org/wiki/Hydrochloric_acid_regeneration

Here is the detailed info, but, it's in spanish :P
http://www.xbot.es/webs/robotika/tutoriales.htm#regenerar

Regards


--
Hector
--
El Pic no pudo Iniciar correctamente.
Inserte el disco de arranque y presione cualquier pin para continuar...


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

On Mon, 11 Sep 2006 19:51:10 +0200, Hector Garcia
<hectorogarcia@...> wrote:

>
> http://en.wikipedia.org/wiki/Hydrochloric_acid_regeneration

This does not seem applicable.

ST

2006/9/11, Stefan Trethan <stefan_trethan@...>:

> On Mon, 11 Sep 2006 19:51:10 +0200, Hector Garcia
> <hectorogarcia@...> wrote:
>
> >
> > http://en.wikipedia.org/wiki/Hydrochloric_acid_regeneration
>
>
> This does not seem applicable.
>

Hi Stefan
:P

I guess you're right.

2 beers and mi bad english makes me see some elephants in pink :-)

Anyway,
Both HCL and H2O2 regenerate FeCl well.
I have a 5 years bottle, still working thanks to this type of regeneration

Regards

P.S. I Apologize for mi english.

--
Hector
--
El Pic no pudo Iniciar correctamente.
Inserte el disco de arranque y presione cualquier pin para continuar...

At 08:04 AM 9/11/2006, lcdpublishing wrote:

>Hi guys,
>
>Went out to etch a board this morning only to find my tank empty -
>luckily I store it inside a bucket so all was well. The Ferric
>Chloride siphoned out through the air hose inlet which passes through
>a hole in the side of the tank. Aside from it completely disolving
>the brass fitting which connects to my compressor, nothing else bad
>happened.

If I may make a suggestion: put a tiny air hole in the hose. Place
the hole at the highest point in the siphon - where the hose goes
over the edge of the bucket.

This hole need not be large - something on the order of a #60 drill
bit is fine. If the hose is plastic, even consider using a hot
needle or a really small soldering iron tip.

The purpose of the hole is to stop a vacuum from forming in the
hose. That stops accidental siphoning action.

My tank is quite large (10 gallon tank filled with 7 gallons) and the
air supply is a vacuum motor blower fed through 1" plastic pipe. I
used a 1/8" hole where the pipe goes over the top of the tank - I
have way more air volume that I need and don't notice the air that is
lost through the hole.

Even though the blower motor is located about 40" below the top of
the liquid, I've NEVER had etchant get down into the blower.

I had initially considered using a 1-way valve but finding a valve
that was low cost, low pressure drop, and impervious to the etchant
seemed impossible at the time. The air hole simply eliminated the
need for the valve.

dwayne

--
Dwayne Reid <dwayner@...>
Trinity Electronics Systems Ltd Edmonton, AB, CANADA
(780) 489-3199 voice (780) 487-6397 fax

Celebrating 22 years of Engineering Innovation (1984 - 2006)
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On Mon, 11 Sep 2006 22:34:53 +0200, Hector Garcia
<hectorogarcia@...> wrote:

>
> Anyway,
> Both HCL and H2O2 regenerate FeCl well.
> I have a 5 years bottle, still working thanks to this type of
> regeneration
> Regards
> P.S. I Apologize for mi english.

I'm still not certain about FeCl regeneration.
Does the FeCl really get regenerated, or does one simply make used-up FeCl
with added CuCl etchant?

Sadly i can not understand the spanish page sufficiently to allow me to
understand that process fully.

ST

On Mon, 11 Sep 2006 22:42:12 +0200, Dwayne Reid <dwayner@...>
wrote:

>
> If I may make a suggestion: put a tiny air hole in the hose. Place
> the hole at the highest point in the siphon - where the hose goes
> over the edge of the bucket.
> This hole need not be large - something on the order of a #60 drill
> bit is fine. If the hose is plastic, even consider using a hot
> needle or a really small soldering iron tip.
> The purpose of the hole is to stop a vacuum from forming in the
> hose. That stops accidental siphoning action.
> My tank is quite large (10 gallon tank filled with 7 gallons) and the
> air supply is a vacuum motor blower fed through 1" plastic pipe. I
> used a 1/8" hole where the pipe goes over the top of the tank - I
> have way more air volume that I need and don't notice the air that is
> lost through the hole.
> Even though the blower motor is located about 40" below the top of
> the liquid, I've NEVER had etchant get down into the blower.
> I had initially considered using a 1-way valve but finding a valve
> that was low cost, low pressure drop, and impervious to the etchant
> seemed impossible at the time. The air hole simply eliminated the
> need for the valve.
> dwayne

That's a good idea!

One could even plug the hole if the escaping air would be a problem,
during etching, with a well-visible plug so it is not forgotten.

The no-return valves for fish tanks are very small (for a 3 or 4mm hose
usually), but made of plastic and rubber parts so basically resistant.


ST

2006/9/11, Stefan Trethan <stefan_trethan@...>:

> I'm still not certain about FeCl regeneration.
> Does the FeCl really get regenerated, or does one simply make used-up FeCl
> with added CuCl etchant?
>
> Sadly i can not understand the spanish page sufficiently to allow me to
> understand that process fully.
>
> ST
>

Hi Again Stefan.
I can't remember the chemistry classes I took at college.
I found the original source in english
http://www.qsl.net/iz7ath/web/02_brew/14_howto/02_clor/index.htm
but, less explicity





--
Hector
--
El Pic no pudo Iniciar correctamente.
Inserte el disco de arranque y presione cualquier pin para continuar...

--- Stefan Trethan <stefan_trethan@...> wrote:

> On Mon, 11 Sep 2006 22:34:53 +0200, Hector Garcia
> <hectorogarcia@...> wrote:
>
> >
> > Anyway,
> > Both HCL and H2O2 regenerate FeCl well.
> > I have a 5 years bottle, still working thanks to
> this type of
> > regeneration
> > Regards
> > P.S. I Apologize for mi english.
>
>
> I'm still not certain about FeCl regeneration.
> Does the FeCl really get regenerated, or does one
> simply make used-up FeCl
> with added CuCl etchant?
>
> Sadly i can not understand the spanish page
> sufficiently to allow me to
> understand that process fully.
>
> ST

You end up with CuCl2, the iron precipitates out as
hydroxide (rust).

- YD.


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--- Hector Garcia <hectorogarcia@...> wrote:
...

> And, carefully melt them with your FeCl. First the HCL and later the H2O2
>
> http://en.wikipedia.org/wiki/Hydrochloric_acid_regeneration
>
> Here is the detailed info, but, it's in spanish :P
> http://www.xbot.es/webs/robotika/tutoriales.htm#regenerar

as previously discussed, that's NOT regeneration, it's creating CuCl etchant on
top of the dirty exhausted FeCl.

if you want to use CuCl then use it 'pure' (clear and not staining) !!



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At 11:17 am (PDT) Tue Sep 12, 2006, Hector Garcia wrote:

>I found the original source in english
>http://www.qsl.net/iz7ath/web/02_brew/14_howto/02_clor/index.htm

Again we have reference to this canard that seems to
claim that Ferric Chloride in aqueous solution isn't acid.

If the pH is around 7 (neutral) there will be so little
Fe3+ ion in solution it will be literally almost drinking
water. (Ferrous Hydroxide flocculation with FeCl is
used to purify water for human consumption.)

At an etching strength, the solution could be as low as pH 2,
which is very acid. It gets that way either by having been
acidulated by the addition of hydrochloric acid (the preferred
course) or by the precipitation of ferrous hydroxide until
equilibrium is found (and a lot of its etching potential is
wasted as brown sludge).

I get the impression that some of our members don't
acidulate their ferric chloride bath... :-(

I also get the impression that some people don't understand
the word "regeneration" - it ought to imply a return to (or very
close to) the original state.

For example, this is what happens in photo-processing labs,
where consistent chemistry is vital for consistent results.
A developer bath is made up from a concentrate and then
topped-up during use with a _different_ concentrate which
attempts to compensate for both the exhaustion of the
original developer and the contaminants introduced by
the film that has been processed. A fixer is regenerated
by the _removal_ of silver or silver salts and the addition
of a top-up concentrate.

Many people here write about "regenerating" FeCl by
methods which make no attempt whatever to remove
the accumulated copper.

This is _not_ regeneration, though if it restores activity
it might be called "reactivation". (I believe ST surmised
that these treatments move the bath towards a
combined FeCl - CuCl chemistry.)

But if you are going to use CuCl etchant, why not go
there directly and forgo the brown sludge?

Similarly, if you are considering using HCl and H2O2 to
reactivate your etchant, why not use them _as_ your
etchant? It's quick, clean and one less chemical to store.


Regards, LenW

--- "Herbert E. Plett" <cachureos@...> wrote:

>
>
> --- Hector Garcia <hectorogarcia@...> wrote:
> ...
> > And, carefully melt them with your FeCl. First the
> HCL and later the H2O2
> >
> >
>

http://en.wikipedia.org/wiki/Hydrochloric_acid_regeneration

> >
> > Here is the detailed info, but, it's in spanish :P
> >
>

http://www.xbot.es/webs/robotika/tutoriales.htm#regenerar

>
> as previously discussed, that's NOT regeneration,
> it's creating CuCl etchant on
> top of the dirty exhausted FeCl.
>
> if you want to use CuCl then use it 'pure' (clear
> and not staining) !!
>

If you can get a sufficient quantity of solid CuCl to
start with it's of course easier. Making it up from
oxygenated HCl and scrap copper is another possibility
but takes quite a bit of time.

I ended up converting from FeCl to CuCl quite without
realizing it. Kept the FeCl in a half-filled two litre
PET bottle (lots of air) and added a dab of HCl after
using it. Since at the time I made less than a board a
month the air had a lot of time to react. After a
while I noticed it worked fine without shaking up the
brown stuff on the bottom.

After a prolonged pause the sludge had all but
solidified so I decanted it, washed the bottle and put
it back in. Another couple of cycles made it quite
clear. The bottle can't be completely cleaned as the
rust gets into the pores in the plastic, but hey, it's
discardable.

I did wonder about the change in color, the lore at
the time was that it was a sign of exhaustion but
still it seemed to work even better than when new.

That's about when I started researching on PCB etching
and after a while I realized what was going on.

I'm taking better care of it now, and with about one
board a week it's going fine.

- YD.


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After reading all your posts, I can realize my mistake. Days ago,
(¿yesterday?) I draw on a paper the supposed chemical reaction, (on mi
limited Chemical acknowledgment) all the results where confusing to me: as a
result of reaction, never had FeCl3 pure, instead there always was CuCl (or
CuCl2) + FeCl3. I checked the formulas again, i went back to the periodic
table and neither heat, Hydrogen or evaporation gave me the answer.

As you say, perhaps a I don't "regenerate" FeCl, perhaps i only "reactivate"
FeCl and also, i don't get FeCl3, i think i have
a mix of FeCl2, CuCl and even water (since commercial hydrochloric acid come
diluted in water).

Now a question raises up my mind: are there some difference between using
FeCl versus CuCl?

YD said in his post "... still it seemed to work even better than when
new...", is that argument giving me an answer?

In the other side, at the first time i made this mix, before to put the HCL
on the FeCl, y made a test mixing HCL and H2O2, i got faster etching
results, but, I still have a kind of romantic feel to that old exhausted
brown liquid and its blue-or-something colored bottle :-) . Maybe some day,
I'll finally say goodbye to it.

Regards
--
Hector
--
El Pic no pudo Iniciar correctamente.
Inserte el disco de arranque y presione cualquier pin para continuar...


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

On Thu, 14 Sep 2006 17:57:04 +0200, Hector Garcia
<hectorogarcia@...> wrote:

>
> Now a question raises up my mind: are there some difference between using
> FeCl versus CuCl?

Yes, differences in etching time and agressiveness, but it all depends on
the parameters you run both etchants at (concentration, temperature,
agitation,...).
They are similar in the results they produce. You should however not heat
CuCl (much) because the HCl will fume/boil at low temperatures (50C
boiling or so and lotsa fumes even below).

> YD said in his post "... still it seemed to work even better than when
> new...", is that argument giving me an answer?

Probably the answer it gives is the "new" CuCl was stronger than the FeCl.

> In the other side, at the first time i made this mix, before to put the
> HCL
> on the FeCl, y made a test mixing HCL and H2O2, i got faster etching
> results,

Etching times are greatly depending on concentrations, esp. H2O2
concentration. I have timed a very small board at 11 or 12 seconds etching
time years ago when i startet with CuCl and did not understand it well. I
used WAY too much H2O2. It should not bubble at all or you produce large
amounts of chlorine gas (bad for all living things, and process engineers,
as they like to joke).

> but, I still have a kind of romantic feel to that old exhausted
> brown liquid and its blue-or-something colored bottle :-) . Maybe some
> day,
> I'll finally say goodbye to it.

I have no longing for the "stain in a bottle" to return.
I like the clear CuCl so i can see when a board is finished, i place a
flourescent light (like for car repair) behind the tank.

The FeCl is probably not hurting, but if it isn't doing any good why
bother? I mean you could also add food coloring to your etchant - but what
for?

ST