Homebrew PCBs

Hi guys,

I use Ferric Chloride for my etchant, I know there is "neater" stuff 
out there, but this works okay for me - plus I have a couple more 
bags of the stuff to use up.

I have a couple questions regarding useage of it...

1) I don't know why I started doing this, but, before etching a 
board, I stir up all the muck at the bottom of the tank. Then I drop 
in my bubble rock and etch my boards.  Is the mucky stuff at the 
bottom the Ferric Chloride crystals or is it just useless muck?  If 
I don't have to stir it up before use - that would save me a bit of 
messy work.

2) I have lost count of how many boards I have etched with the batch 
I am using right now.  If I were to guess, I would have to say 
probably in the area of 20-25 8" x 10" boards.  Most of those board 
were single sided and all copper removed except for the traces and 
pads.  It currently takes about 20~25 minutes to etch a board with 
the chemicals at around 68 degrees F.  To be honest, I have no idea 
how long it took when I first mixed up the batch :-)  So, I am just 
trying to get a feel for the "Status" of this batch as to whether 
it's time to dump it or keep using it?

3) I know that for some chemical etchants, you use heaters to speed 
up the process.  I recall someone telling me not to use a heater 
with Ferric Chloride so I never did.  However, I did buy a fish tank 
heater, but never used it.  I don't mind waiting 20 minutes to etch 
a board if it is safer than doing it faster with the heater.  If a 
heater is okay to use with this stuff, at what temperature should I 
shoot for? (SAFELY!)

Thanks guys!

Chris

----- Original Message ----- 

From: "lcdpublishing" <lcdpublishing@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Saturday, May 06, 2006 10:10 PM
Subject: [Homebrew_PCBs] Ferric Chloride - muck at bottom of tank question


> Hi guys,
>
> I use Ferric Chloride for my etchant, I know there is "neater" stuff
> out there, but this works okay for me - plus I have a couple more
> bags of the stuff to use up.
>
> I have a couple questions regarding useage of it...
>
> 1) I don't know why I started doing this, but, before etching a
> board, I stir up all the muck at the bottom of the tank. Then I drop
> in my bubble rock and etch my boards.  Is the mucky stuff at the
> bottom the Ferric Chloride crystals or is it just useless muck?  If
> I don't have to stir it up before use - that would save me a bit of
> messy work.
>
> 2) I have lost count of how many boards I have etched with the batch
> I am using right now.  If I were to guess, I would have to say
> probably in the area of 20-25 8" x 10" boards.  Most of those board
> were single sided and all copper removed except for the traces and
> pads.  It currently takes about 20~25 minutes to etch a board with
> the chemicals at around 68 degrees F.  To be honest, I have no idea
> how long it took when I first mixed up the batch :-)  So, I am just
> trying to get a feel for the "Status" of this batch as to whether
> it's time to dump it or keep using it?
>
> 3) I know that for some chemical etchants, you use heaters to speed
> up the process.  I recall someone telling me not to use a heater
> with Ferric Chloride so I never did.  However, I did buy a fish tank
> heater, but never used it.  I don't mind waiting 20 minutes to etch
> a board if it is safer than doing it faster with the heater.  If a
> heater is okay to use with this stuff, at what temperature should I
> shoot for? (SAFELY!)

Try adding some HCl, that should get rid of the sludge. Adding H2O2 will 
also help, with the HCl it will convert cuprous chloride into cupric 
chloride. Doing that should allow you to use the solution indefinitely, if 
you wish. Heating to about 50C will speed things up a lot. I always heat my 
FeCl3 etchant by putting the etchant container inside a larger one 
containing hot water.

Leon

Leon

On Sat, 06 May 2006 23:27:07 +0200, Leon Heller  
<leon.heller@...> wrote:

>
>
> Try adding some HCl, that should get rid of the sludge. Adding H2O2 will
>
> also help, with the HCl it will convert cuprous chloride into cupric
>
> chloride. Doing that should allow you to use the solution indefinitely,  
> if
>
> you wish. Heating to about 50C will speed things up a lot. I always heat  
> my
>
> FeCl3 etchant by putting the etchant container inside a larger one
>
> containing hot water.
>
>
> Leon


Do not heat any etchant containing HCl. HCl boils at very low temperature  
and large amounts of corrosive gas are released even below that.

ST

On Sat, 06 May 2006 23:10:56 +0200, lcdpublishing  
<lcdpublishing@...> wrote:

>
> 3) I know that for some chemical etchants, you use heaters to speed
>
> up the process.  I recall someone telling me not to use a heater
>
> with Ferric Chloride so I never did.  However, I did buy a fish tank
>
> heater, but never used it.  I don't mind waiting 20 minutes to etch
>
> a board if it is safer than doing it faster with the heater.  If a
>
> heater is okay to use with this stuff, at what temperature should I
>
> shoot for? (SAFELY!)
>
>
> Thanks guys!
>
>
> Chris


FeCl is best at about 45C to 50C i think.

ST

----- Original Message ----- 

From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Saturday, May 06, 2006 10:30 PM
Subject: Re: [Homebrew_PCBs] Ferric Chloride - muck at bottom of tank 
question


> On Sat, 06 May 2006 23:27:07 +0200, Leon Heller
> <leon.heller@...> wrote:
> Mime-Version: 1.0
> Content-Transfer-Encoding: 8bit
> Content-Type: text/plain; charset=iso-8859-15
>
>>
>>
>> Try adding some HCl, that should get rid of the sludge. Adding H2O2 will
>>
>> also help, with the HCl it will convert cuprous chloride into cupric
>>
>> chloride. Doing that should allow you to use the solution indefinitely,
>> if
>>
>> you wish. Heating to about 50C will speed things up a lot. I always heat
>> my
>>
>> FeCl3 etchant by putting the etchant container inside a larger one
>>
>> containing hot water.
>>
>>
>> Leon
>
>
> Do not heat any etchant containing HCl. HCl boils at very low temperature
> and large amounts of corrosive gas are released even below that.

If a small amount is added, there won't be any fumes when it is heated. I've 
never noticed any when I've done this.

Leon 

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On Sat, 06 May 2006 23:40:00 +0200, Leon Heller  
<leon.heller@...> wrote:

>
>
> If a small amount is added, there won't be any fumes when it is heated.  
> I've
>
> never noticed any when I've done this.
>
>
> Leon


I know the boiling point of dilute solutions is high, even above that of  
water.
But i have heated CuCl to about 50C once, and smelled a huge quantity of  
fumes from that tiny glass, much more than from the 2 liter tank (no smell  
noticeable). So i know the heating caused much more fumes to be released  
than normal. 38% HCl boils at 48C, i think even when not boiling higher  
temperature means much more fumes, like a steaming cup of tea.

ST

----- Original Message ----- 

From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Saturday, May 06, 2006 10:57 PM
Subject: Re: [Homebrew_PCBs] Ferric Chloride - muck at bottom of tank 
question


> On Sat, 06 May 2006 23:40:00 +0200, Leon Heller
> <leon.heller@...> wrote:
>
>>
>>
>> If a small amount is added, there won't be any fumes when it is heated.
>> I've
>>
>> never noticed any when I've done this.
>>
>>
>> Leon
>
>
> I know the boiling point of dilute solutions is high, even above that of
> water.
> But i have heated CuCl to about 50C once, and smelled a huge quantity of
> fumes from that tiny glass, much more than from the 2 liter tank (no smell
> noticeable). So i know the heating caused much more fumes to be released
> than normal. 38% HCl boils at 48C, i think even when not boiling higher
> temperature means much more fumes, like a steaming cup of tea.

There won't be any free HCl, it will all have reacted with the sludge. 
That's why I don't get any fumes.

Leon 

---
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Hmm, boiling - gasses - more chemicals - guy afraid of acids.  I think 
I will be just happy waiting the 20 minutes or so :-)

Thanks guys, I think I will stick with what I got till I get a bit 
more experience under my belt. What can I say, I used to drive race 
cars, I have worked around industrial machinery all my life, I play 
with guns, but I am afraid of gasses and acids. Just too spooky.

Chris

On Sun, 07 May 2006 00:04:47 +0200, Leon Heller  
<leon.heller@...> wrote:

> There won't be any free HCl, it will all have reacted with the sludge.
>
> That's why I don't get any fumes.
>
>
> Leon


Yes, probably! There is always some free HCl in CuCl.

ST

>Try adding some HCl, that should get rid of the sludge. Adding H2O2 will 
>also help, with the HCl it will convert cuprous chloride into cupric 
>chloride.

How much is a little?

Regards,

Terry

----- Original Message ----- 

From: "Blue" <jo001k1132@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Sunday, May 07, 2006 1:43 AM
Subject: Re: [Homebrew_PCBs] Ferric Chloride - muck at bottom of tank 
question


> >Try adding some HCl, that should get rid of the sludge. Adding H2O2 will
>>also help, with the HCl it will convert cuprous chloride into cupric
>>chloride.
>
> How much is a little?

Depends on how much is in the tank. Just add a little at a time until the 
sludge disappears.

Leon 

---
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> --- In Homebrew_PCBs@yahoogroups.com, "Leon Heller" leon.heller@>
> wrote:
> Try adding some HCl, that should get rid of the sludge. Adding H2O2 
> will 
> also help, with the HCl it will convert cuprous chloride into cupric 
> chloride. Doing that should allow you to use the solution 
> indefinitely, if 
> you wish. Heating to about 50C will speed things up a lot. I always 
> heat my 
> FeCl3 etchant by putting the etchant container inside a larger one 
> containing hot water.
> 
> Leon
> 

You can get 40 volume H2O2 (peroxide, hair bleach) at Sally Beauty 
Supply without needing a license or whatnot to purchase it. I've been 
using it to regenerate FeCl3 for about three years now. I haven't had 
to add any acid for a long time. I use a whole 32 oz bottle per 2 
gallons of etchant. It seems to etch faster than the original etchant.

Be careful with the H2O2, while FeCL3 doesn't cause burns quickly, 
peroxide at that strength will. Always mix outdoors and add slowly, 
this creates large amounts of foaming and heat.

On Sun, 07 May 2006 18:07:13 +0200, fenrir_co <fenrir@...>  
wrote:

> Be careful with the H2O2, while FeCL3 doesn't cause burns quickly,
>
> peroxide at that strength will. Always mix outdoors and add slowly,
>
> this creates large amounts of foaming and heat.
>


Sounds like a rather wild procedure ;-)
Any gas that is released when adding H2O2 is probably something you would  
rather wish to keep in the etchant (like oxygen), so if you get bubbles  
that is not always a good thing. At least that's how it is with CuCl,  
there you do not want to add so much to cause bubbles to form and heating,  
because it is only a waste of chemicals.

I'm not quite sure if i had the choice between nursing FeCl on to last  
forever, and starting with clean, fresh CuCl with no FeCl at all, if i  
would choose to use any FeCl. I don't quite see the advantage, i mean, is  
it actually regenerated or is this only CuCl with some used up FeCl  
swimming around in it and making things dirty and blocking the view?

ST

----- Original Message ----- 

From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Sunday, May 07, 2006 5:26 PM
Subject: Re: [Homebrew_PCBs] Re: Ferric Chloride - muck at bottom of tank 
question


> On Sun, 07 May 2006 18:07:13 +0200, fenrir_co <fenrir@...>
> wrote:
>
>> Be careful with the H2O2, while FeCL3 doesn't cause burns quickly,
>>
>> peroxide at that strength will. Always mix outdoors and add slowly,
>>
>> this creates large amounts of foaming and heat.
>>
>
>
> Sounds like a rather wild procedure ;-)
> Any gas that is released when adding H2O2 is probably something you would
> rather wish to keep in the etchant (like oxygen), so if you get bubbles
> that is not always a good thing. At least that's how it is with CuCl,
> there you do not want to add so much to cause bubbles to form and heating,
> because it is only a waste of chemicals.
>
> I'm not quite sure if i had the choice between nursing FeCl on to last
> forever, and starting with clean, fresh CuCl with no FeCl at all, if i
> would choose to use any FeCl. I don't quite see the advantage, i mean, is
> it actually regenerated or is this only CuCl with some used up FeCl
> swimming around in it and making things dirty and blocking the view?

The ferric chloride gets regenerated, of course. The solution is rather 
dark, though.

Leon


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On May 7, 2006, at 12:07 PM, fenrir_co wrote:

> You can get 40 volume H2O2 (peroxide, hair bleach) at Sally Beauty
> Supply without needing a license or whatnot to purchase it.


!!  Hold it, 40 % H2O2 ?    Cool !   I've been looking for that as a  
green herbicide !

Handle with gloves, and face mask, on a windless day.... but burns  
back weeds without leaving residue in the soil.

> BillC wrote:
>
> !!  Hold it, 40 % H2O2 ?    Cool !   I've been looking for that as a  
> green herbicide !
> 
> Handle with gloves, and face mask, on a windless day.... but burns  
> back weeds without leaving residue in the soil.
>

H2O2 isn't the only one that is good for weeding.

A bit of C2H2 mixed with a bit of O2 does a ripper job too.

--- In Homebrew_PCBs@yahoogroups.com, William Carr <Jkirk3279@...> 
wrote:
>
> 
> On May 7, 2006, at 12:07 PM, fenrir_co wrote:
> 
> > You can get 40 volume H2O2 (peroxide, hair bleach) at Sally Beauty
> > Supply without needing a license or whatnot to purchase it.
> 
> 

'Volume' doesn't mean percent. I'm not sure of the exact conversion, 
but I believe the strength is only about 15/20%. They have 60 volume 
as well, but only in cream, not in pure liquid.

--- In Homebrew_PCBs@yahoogroups.com, "fenrir_co" <fenrir@...> wrote:
>
<snip> 
> 
> 'Volume' doesn't mean percent. I'm not sure of the exact conversion, 
> but I believe the strength is only about 15/20%. They have 60 volume 
> as well, but only in cream, not in pure liquid.
>

From what I've found, the 40 Volume stuff is about 12%, 30 Volume is 
about 9%, and 20 Volume about 6%.


Regards, Bob

Hello William,

  Monday, May 8, 2006, 1:18:45 AM, you wrote:


> !!  Hold it, 40 % H2O2 ?    Cool !   I've been looking for that as a
> green herbicide !



  40% Vol H2O2 is in fact 12% H2O2!

-- 
 Best regards,
 Zoran A. Scepanovic
 zastos@...

*********
If a program is useless, it will have to be documented. 
*********

Please be advised what was said may be absolutely wrong, and hereby this disclaimer follows.  I reserve the right to be wrong and admit it in front of the entire world.



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

--- fenrir_co <fenrir@...> wrote:

> --- In Homebrew_PCBs@yahoogroups.com, William Carr
> <Jkirk3279@...> 
> wrote:
> >
> > 
> > On May 7, 2006, at 12:07 PM, fenrir_co wrote:
> > 
> > > You can get 40 volume H2O2 (peroxide, hair
> bleach) at Sally Beauty
> > > Supply without needing a license or whatnot to
> purchase it.
> > 
> > 
> 
> 'Volume' doesn't mean percent. I'm not sure of the
> exact conversion, 
> but I believe the strength is only about 15/20%.
> They have 60 volume 
> as well, but only in cream, not in pure liquid.
> 

A bottle I looked at said 20 vol/6% on the label, so
it looks like the scale factor is 0.3% per volume. So
40 volumes would be 12%. I saw somewhere what this
volume business is all about but I can't quite recall
it now. I think it had to do with the weight of the
solution.

- YD.


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----- Original Message ----- 
From: "YD" <yd_br@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, May 08, 2006 11:44 AM
Subject: Re: [Homebrew_PCBs] Re: Ferric Chloride - muck at bottom of tank 
question


>
>
> --- fenrir_co <fenrir@...> wrote:
>
>> --- In Homebrew_PCBs@yahoogroups.com, William Carr
>> <Jkirk3279@...>
>> wrote:
>> >
>> >
>> > On May 7, 2006, at 12:07 PM, fenrir_co wrote:
>> >
>> > > You can get 40 volume H2O2 (peroxide, hair
>> bleach) at Sally Beauty
>> > > Supply without needing a license or whatnot to
>> purchase it.
>> >
>> >
>>
>> 'Volume' doesn't mean percent. I'm not sure of the
>> exact conversion,
>> but I believe the strength is only about 15/20%.
>> They have 60 volume
>> as well, but only in cream, not in pure liquid.
>>
>
> A bottle I looked at said 20 vol/6% on the label, so
> it looks like the scale factor is 0.3% per volume. So
> 40 volumes would be 12%. I saw somewhere what this
> volume business is all about but I can't quite recall
> it now. I think it had to do with the weight of the
> solution.

It's the amount of oxygen it can release - 20 vol means it can produce 20 
times its volume of O2. One ml of H2O2 will produce 20 ml of O2.

Leon 

---
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--- Leon Heller <leon.heller@...> wrote:

<adjusted for bandwidth saving time>

> 
> It's the amount of oxygen it can release - 20 vol
> means it can produce 20 
> times its volume of O2. One ml of H2O2 will produce
> 20 ml of O2.
> 
> Leon 

Thanks, nice to know.

- YD.


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