[sdiy] PCB etching and safety

[Ken Stone]

The copper can easilly be reclaimed from the expended FeCl. Drop old nails
or similar iron into the mix. The result will be ferrous chloride, and a
whole lot of copper "crystals" at the bottom of the gunk. 

Ken

>    I solve the problem by not doing any home etching...and 30 years ago,
when I
>did do it, well, I just poured it down the drain...since then I have learned
>different...the biggest problem with dumping FeCl down the drain isn't the
>FeCl...but the CuCl you get after you use it.  Copper is very toxic to the
little
>bugs that digest the sewage.  A friend of mine used to run a PC board
>shop...although he used Hydrogen Peroxide-Sulfuric Acid to etch boards, he
had the
>same problem...removing the Copper from the waste etchant.  In theory, FeCl
would
>need to be hauled away by a toxic waste disposal company...
>
>    I am also not sure how using FeCl would conflict with our local zoning
>laws...I do know that I am violating local zoning laws by just having a
Lathe and
>Milling machine in my garage (according to the local Zoning Law Nazis that
makes
>me a manufacturer in a residential zone).  Although, tracing FeCl back to its
>source in a residential area would be tough.
>
>Ian Fritz wrote:
>
>> Jim --
>>
>> So ... what *do* you do with it?
>>
>> I've heard of mixing it into some concrete, but I think it could still
>> leach out over time.
>>
>>    Ian
>>
>> At 11:24 PM 1/7/2003, patchell wrote:
>> > >
>> > > Don't pour the spent Ferric Chl down the drain, it will melt your pipes.
>> >
>> >     Good advice from an environmental standpoint, it is not at all good for
>> >your septic tank (if you have one), and the people at the sewage treatment
>> >plant will get upset if they knew you did that.
>> >
>> >     As far as melting your pipes?...actually I have a funny story about
>> >that.  One of the places I worked for about 20 years ago would DIY PC boards
>> >for prototypes, and they used FeCl.  They would pour the stuff down the
>> >bathroom sink.  The drain pipe (trap) was Chrome Plated Brass pipe.  One day
>> >I noticed that the trap was dripping...I poked at the drip and my finger
went
>> >right through the pipe...the only thing that was left was the chrome...I
>> >don't know how it was holding its shape.
>> >
>> >     If you have ABS sewer pipe like I do, FeCl will not touch that at all,
>> >still, don't pour it down the drain in any case, it just ain't good for what
>> >is down stream.
>
>--
> -Jim
>------------------------------------------------
>* Visit:http://www.silcom.com/~patchell/
>*-----------------------------------------------
>*I'm sure glad Merry Christmas comes just once a year
>* -Yogi Yorgensen
>------------------------------------------------
>
>
>
_______________________________________________________________________
Ken Stone   sasami at hotkey.net.au  
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>