Homebrew PCBs

As a chemist in industry, I am constantly amazed on how many of the 
homebrew pcb'ers use hazardous chemicals without the proper respect 
and protective equipment.

If there is any question about the hazards of a chemical, google the 
MSDS (Material Safety Data Sheet in the US) for the proper handling 
procecures. These procedures are based on industry wide experience in 
reducing injuries.

Eye protection is basic.

Be Safe,

Myc

Hi,

Glad you rang in on this topic...

What is the proper way to dispose of used ferric chloride?  Is there 
a way to rejuvinate it?  Someone mentioned adding sulfuric acid, but 
everyone is imprecise about ratios.  Is there a simple way to 
determine how much life is left in the etching solution?  Is there 
an inexpensive way to precipitate the copper out of the solution and 
end up with just ferric chloride?

I'm hesitant to use some of the other recipes.  I've used ferric 
chloride for many years and my main concern was not breathing the 
chlorine gas that gets released.  Now, that I'm more environmentally 
aware, I want to know how to dispose of it properly.  An old bottle 
I had from Radio Shack said to put it down the toilet.  I'm sure 
that's not a good thing to do these days...

Regards,
Dennis

--- In Homebrew_PCBs@yahoogroups.com, "mycroft2152" 
<mycroft2152@...> wrote:
>
> As a chemist in industry, I am constantly amazed on how many of 
the 
> homebrew pcb'ers use hazardous chemicals without the proper 
respect 
> and protective equipment.

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

From: "dl5012" <dl5012@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, February 07, 2006 8:17 PM
Subject: [Homebrew_PCBs] Re: Dangerous Chemicals


> Hi,
>
> Glad you rang in on this topic...
>
> What is the proper way to dispose of used ferric chloride?  Is there
> a way to rejuvinate it?  Someone mentioned adding sulfuric acid, but
> everyone is imprecise about ratios.  Is there a simple way to
> determine how much life is left in the etching solution?  Is there
> an inexpensive way to precipitate the copper out of the solution and
> end up with just ferric chloride?

Adding H2O2 and a little HCl should convert any cuprous chloride in the 
solution to cupric chloride, which is an etchant in its own right. Any 
ferrous chloride would get converted back to the ferric form. I've tried it 
and it seems to work.

>
> I'm hesitant to use some of the other recipes.  I've used ferric
> chloride for many years and my main concern was not breathing the
> chlorine gas that gets released.  Now, that I'm more environmentally
> aware, I want to know how to dispose of it properly.  An old bottle
> I had from Radio Shack said to put it down the toilet.  I'm sure
> that's not a good thing to do these days...

I just pour it down the bog!

Leon 

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--- In Homebrew_PCBs@yahoogroups.com, "Leon Heller" <leon.heller@...>
wrote:
>
> ----- Original Message ----- 
> From: "dl5012" <dl5012@...>
> To: <Homebrew_PCBs@yahoogroups.com>
> Sent: Tuesday, February 07, 2006 8:17 PM
> Subject: [Homebrew_PCBs] Re: Dangerous Chemicals
> 
> 
> > Hi,
> >
> > Glad you rang in on this topic...
> >
> > What is the proper way to dispose of used ferric chloride?  Is there
> > a way to rejuvinate it?  Someone mentioned adding sulfuric acid, but
> > everyone is imprecise about ratios.  Is there a simple way to
> > determine how much life is left in the etching solution?  Is there
> > an inexpensive way to precipitate the copper out of the solution and
> > end up with just ferric chloride?
> 
> Adding H2O2 and a little HCl should convert any cuprous chloride in the 
> solution to cupric chloride, which is an etchant in its own right. Any 
> ferrous chloride would get converted back to the ferric form. I've
tried it 
> and it seems to work.

Me, too.  You can find HCl, as Muratic Acid, in most hardware 
stores.

> > I'm hesitant to use some of the other recipes.  I've used ferric
> > chloride for many years and my main concern was not breathing the
> > chlorine gas that gets released.  Now, that I'm more environmentally
> > aware, I want to know how to dispose of it properly.  An old bottle
> > I had from Radio Shack said to put it down the toilet.  I'm sure
> > that's not a good thing to do these days...
> 
> I just pour it down the bog!

The Ferric Chloride isn't that bad of a problem.  The problem is
that used solution contains soluable Copper compounds, and these
are lethal to most biological organisms.

> Leon 

Dave

--- In Homebrew_PCBs@yahoogroups.com, "dl5012" <dl5012@...> wrote:
>
> Hi,
> 
> Glad you rang in on this topic...
> 
> What is the proper way to dispose of used ferric chloride?  Is there 
> a way to rejuvinate it?  Someone mentioned adding sulfuric acid, but 
> everyone is imprecise about ratios.  

No, not Sulfuric Acid; use Hydrochloric Acid instead.  As for how
much, the appropriate amount is some.  

> Is there a simple way to 
> determine how much life is left in the etching solution?  

When it starts taking too long to etch, there's not enough life
left.

> Is there 
> an inexpensive way to precipitate the copper out of the solution and 
> end up with just ferric chloride?

I once tried electroplating out the Copper (Carbon cathode, Iron
anode).  It sort of kind of worked (I ended up with Copper crystals 
on the cathode.), but I don't remember if the resulting solution 
was any good for etching or not (or, whether I even tried it).  My
intent was to remove the Copper and replace it with something less
biologically nasty than Copper.  Maybe if we have an electro-chemist 
in the house, he can advise on such a procedure (Beware of 
outgassing Chlorine gas if you try such a procedure!).

> I'm hesitant to use some of the other recipes.  I've used ferric 
> chloride for many years and my main concern was not breathing the 
> chlorine gas that gets released.  Now, that I'm more environmentally 
> aware, I want to know how to dispose of it properly.  An old bottle 
> I had from Radio Shack said to put it down the toilet.  I'm sure 
> that's not a good thing to do these days...

Actually, Ferric Chloride isn't that bad (It's been used as a 
nutritional supplement in it's food grade form.).  Unfortunately, 
used solution has a lot of Copper Chloride in it, which is deadly 
to most biological organisms.

> Regards,
> Dennis

Dave

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

From: "Dave" <wa4qal@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, February 07, 2006 8:46 PM
Subject: [Homebrew_PCBs] Re: Dangerous Chemicals


> --- In Homebrew_PCBs@yahoogroups.com, "Leon Heller" <leon.heller@...>
> wrote:
>>
>> ----- Original Message ----- 
>> From: "dl5012" <dl5012@...>
>> To: <Homebrew_PCBs@yahoogroups.com>
>> Sent: Tuesday, February 07, 2006 8:17 PM
>> Subject: [Homebrew_PCBs] Re: Dangerous Chemicals
>>
>>
>> > Hi,
>> >
>> > Glad you rang in on this topic...
>> >
>> > What is the proper way to dispose of used ferric chloride?  Is there
>> > a way to rejuvinate it?  Someone mentioned adding sulfuric acid, but
>> > everyone is imprecise about ratios.  Is there a simple way to
>> > determine how much life is left in the etching solution?  Is there
>> > an inexpensive way to precipitate the copper out of the solution and
>> > end up with just ferric chloride?
>>
>> Adding H2O2 and a little HCl should convert any cuprous chloride in the
>> solution to cupric chloride, which is an etchant in its own right. Any
>> ferrous chloride would get converted back to the ferric form. I've
> tried it
>> and it seems to work.
>
> Me, too.  You can find HCl, as Muratic Acid, in most hardware
> stores.
>
>> > I'm hesitant to use some of the other recipes.  I've used ferric
>> > chloride for many years and my main concern was not breathing the
>> > chlorine gas that gets released.  Now, that I'm more environmentally
>> > aware, I want to know how to dispose of it properly.  An old bottle
>> > I had from Radio Shack said to put it down the toilet.  I'm sure
>> > that's not a good thing to do these days...
>>
>> I just pour it down the bog!
>
> The Ferric Chloride isn't that bad of a problem.  The problem is
> that used solution contains soluable Copper compounds, and these
> are lethal to most biological organisms.

The amounts will be undetectable by the time it gets to the sewage plant, 
with the enorrmous dilution that will have taken place. I used to deal with 
the water company where I worked a long time ago, and they used to check our 
effluent regularly - I didn't know when they would be coming, though. They 
used to be most concerned about chlorinated solvents (which we used a lot) 
killing their bugs.

Leon

> The amounts will be undetectable by the time it gets to the sewage
> plant, with the enorrmous dilution that will have taken place.

Some hazmat agencies here in the US seem to recommend diluting small 
quantities (gallon or less) of spent Ferric Chloride with water and 
pouring it down the drain. Frankly, I'm more worried about my pipes 
than the environment in such cases. Oddly, I have no such worry when it 
comes to spent Ammonium Persulphate.


--- In Homebrew_PCBs@yahoogroups.com, "Leon Heller" <leon.heller@...> 
wrote:
>

Hi,

I'm on a septic and well system and I can tell you, no significant 
amounts of spent ferric chloride will be going down my drains.

Kill the beneficial bacteria -- clog my drain field -- pay > $10K to 
repair (not to mention the stink that would make).  Or kill the 
biological organisms I care most about...

I'll save it in glass jars and get rid of it during one of the annual 
hazardous waste disposal events.

Regards,
Dennis

--- In Homebrew_PCBs@yahoogroups.com, "derekhawkins" <eldata@...> 
wrote:
>
> > The amounts will be undetectable by the time it gets to the sewage
> > plant, with the enorrmous dilution that will have taken place.
> 
> Some hazmat agencies here in the US seem to recommend diluting small 
> quantities (gallon or less) of spent Ferric Chloride with water and 
> pouring it down the drain. Frankly, I'm more worried about my pipes 
> than the environment in such cases. Oddly, I have no such worry when 
it 

> comes to spent Ammonium Persulphate.
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Leon Heller" <leon.heller@> 
> wrote:
> >
>

--- In Homebrew_PCBs@yahoogroups.com, "dl5012" <dl5012@...> wrote:
(snip)
> What is the proper way to dispose of used ferric chloride?
(snip)

Go to the grocery store and but a box of washing soda (sodium
carbonate) for a dollar or two.  When you have exausted the ferric
chloride, or just wish to dispose of some, just slowly neutralize it
(in an oversized container) with washing soda.  I say, "slowly",
because the reaction will produce a lot of foam.  When there is no
more visible reaction, the ferric chloride will have almost totally
been converted to insoluble iron and copper carbonate, that will
settle to the bottom as a mud.  After that happens, you can pour the
liquid (salt water) down the drain, and put the mud in the garbage. 
In effect, you have recreated some iron and copper ore.

Other carbonate based chemicals can also be used (sodium bicarbonate,
calcium carbonate or lime, even portland cement).  But sodium
carbonate is very cheap; the liquid residue is just salt and any extra
washing soda, and sodium carbonate also serves as a developer for many
kinds of positive resist, so it is handy to have some around.

John Popelish wrote:

> --- In Homebrew_PCBs@yahoogroups.com, "dl5012" <dl5012@...> wrote:
> (snip)
> 
>>What is the proper way to dispose of used ferric chloride?
> 
> 
> Other carbonate based chemicals can also be used (sodium bicarbonate,
> calcium carbonate or lime, even portland cement).  But sodium
> carbonate is very cheap; the liquid residue is just salt and any extra
> washing soda, and sodium carbonate also serves as a developer for many
> kinds of positive resist, so it is handy to have some around.
> 

I experimented with difference neutralizing chemicals for copper 
chloride etchants (containing > 150g/L of ionized copper!!!). Safest, 
cheapest and easiest was neutralizing with lime. See my page:

http://members.optusnet.com.au/~eseychell/PCB/etching_CuCl/index.html#Disposal

Leon Heller wrote:
> ----- Original Message ----- 
> From: "dl5012" <dl5012@...>
> To: <Homebrew_PCBs@yahoogroups.com>
> Sent: Tuesday, February 07, 2006 8:17 PM
> Subject: [Homebrew_PCBs] Re: Dangerous Chemicals
> 
>>Hi,
>>
>>Glad you rang in on this topic...
>>
>>What is the proper way to dispose of used ferric chloride?  Is there
>>a way to rejuvinate it?  Someone mentioned adding sulfuric acid, but
>>everyone is imprecise about ratios.  Is there a simple way to
>>determine how much life is left in the etching solution?  Is there
>>an inexpensive way to precipitate the copper out of the solution and
>>end up with just ferric chloride?
> 
> Adding H2O2 and a little HCl should convert any cuprous chloride in the 
> solution to cupric chloride, which is an etchant in its own right. Any 
> ferrous chloride would get converted back to the ferric form. I've tried it 
> and it seems to work.
> 
>>I'm hesitant to use some of the other recipes.  I've used ferric
>>chloride for many years and my main concern was not breathing the
>>chlorine gas that gets released.  Now, that I'm more environmentally
>>aware, I want to know how to dispose of it properly.  An old bottle
>>I had from Radio Shack said to put it down the toilet.  I'm sure
>>that's not a good thing to do these days...
> 
> I just pour it down the bog!

Copper-saturated ferric chloride is the most excellent weed killer. Just
one spray will make a black dead spot on the lawn, so aim carefully.

Pouring it down the dunny or drain should be an excellent way of
killing any tree roots getting into the pipes.