Homebrew PCBs

JanRwl@... wrote:

> In a message dated 11/13/2003 1:48:21 PM Central Standard Time, 
> alan@... writes:
> Still, recharge the stuff instead of throwing it away.  It should be 
> cheaper to use nails and plate the copper back out than to buy new etchant.
> Alan!  Describe for us (again?) how an ignernt non-chemist can DO that???  
> Thanks!
> 

   I have one running right now.  Take a small power supply, (mine is a 
+ and - 5V test supply I made for ICs, using around an amp at the 10 
volts for this for my 10 oz or so of etchant) and two of the aligator 
test clip leads and two nails.  Hook one nail up to + with one lead, and 
the other nail to -.  Stick them both in the used etchant and the + nail 
will be eaten away and give up iron and the - nail collects the copper. 
  Note the copper will be like an old penny brown, not the bright shiny 
copper of a real electroplating process, and it also will have some of 
the iron mixed in.  It's extremely easy and much cheaper than new 
etchant.  Since you're replacing the iron by the new nail being eaten 
away, the original iron that was in the FeCl stays in the jar.  You 
should have already noticed it though as the brown sludge that developed 
as the iron was being replaced by the etched copper.  Can't easily get 
that same iron back in though since it's spread all over and hard to 
electrify.

   Note to get bright common nails or similar, you want just the iron or 
steel not zinc plating etc.  Also leave the nails partially out, so your 
test clips aren't in there.

Alan