[sdiy] Etching PCBs with non-toxic chemicals

[Elliot Williams]

On Sun, 6 Mar 2011 23:59:22 +0100
Csaba Zvekan <czvekan at gmail.com> wrote:

> So , I basically add little pieces (sraps) of aluminum and let it sit there for a few days ? Do I still have a piece of metal in there after days? Or is it completely dissolved ?
> And could the liquid afterwards theoretically dumped in my septic tank ? Or is it gonna cause other problems further down in the septic system ? Like killing all the fermentation ? 

Or you could just not dispose of it.  

The copper in solution will recharge on exposure to oxygen (or addition of peroxide).  As long as the acid levels are high enough, and the copper in solution looks green rather than brown, it makes a good etchant.  

http://members.optusnet.com.au/~eseychell/PCB/etching_CuCl/index.html
and
http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc