Homebrew PCBs

johnman_001 wrote:
>>More of interest is if the ferric cloride is a danger to wastewater 
>>cleaning facilities.
>>It's just not ok to make them trouble if you can avoid it.
> 
> 
> 
> The first time I actually saw Ferric Chloride used in an industrial 
> application was in a wastewater treatment system!  I asked what it 
> was used for and they told me that it was used to precipitate out 
> other chemicals (if I remember correctly).  I was also supprised that 
> the ferric chloride was stored/used in a very large open topped poly 
> tank.


   Look up cow manure, they use it by the 5 gallon bucket to leach out 
metals for treating waste.  But you're also not pouring unused Ferric 
Chloride down the drain either.  They're using it to lock up worse 
items, you're adding it and worse items to the water.



> 
> Closer to topic....
> 
> I too am wanting to try regenerating some of my used ferric chloride 
> using the iron nail - Power supply method.
> 
> Is there any way to know when to stop the plating process or is this 
> simply trial and error at this point????
> 


   First few times I got dark gunk when I wiped the terminal then I was 
getting an even brown.  I believe the even brown was iron oxide, it was 
the same color as a recording tape or floppy disk.  That should mean 
most of the copper was gone, but I haven't etched another board yet to 
see how it goes.  Just do it, nails are cheap and about the worst you 
will do is waste an extra nail or two plating just iron onto the cathode.

Alan