Yea, from what I read, you just let the let the pump bubble/aerate
the solution for a while, and then it changes back to the
green color.... and it seems to work :)
If this were to become popular, it would put those Ferric Chloride
distributors out of business.
Someone on the list mentioned earlier that they were hospitalized
for copper poisoning. I am slightly concerned about the toxicity
of the stuff. From the MSDS, it doesn't sound very toxic, but
the fact that the guy was sick enough to be put in the hospital
concerns me..
~Rolan
--- In Homebrew_PCBs@yahoogroups.com, Adam Seychell <adam_seychell@y...> wrote:
>
>
> Ned Konz wrote:
> > On Monday 03 March 2003 12:06 am, rolanyang <rolan@h...>
> > wrote:
>
> >>The neat thing about using CuCl2 is that the byproduct
> >>of the etching process generates more CuCl2. And because of
> >>this, the etchant solution can be used over and over.
> >
> >
> > No, the etching reaction (a reduction reaction) generates CuCl .
> >
> > Cu + CuCl2 => 2 CuCl
> >
> > People do regenerate the etchant using oxidizers (like chlorine gas or
> > hydrogen peroxide).
> >
> > 2 CuCl + H202 + 2 HCl => 2 CuCl2 + 2 H2O
> >
> > 2CuCl + Cl2 => 2 CuCl2
> >
>
> Ordinary old air can regenerate the solution too. The cuprous
> chloride complex is quickly oxidized to the cupric state (Cu++)
> with dissolved oxygen. Air is widely available and doesn't cost
> anything. I don't know why more hobbyists are using this etchant.