>From: "Phil" <phil1960us@...>
>Reply-To: Homebrew_PCBs@yahoogroups.com
>To: Homebrew_PCBs@yahoogroups.com
>Subject: [Homebrew_PCBs] Re: Regenerating etchant??
>Date: Mon, 15 Nov 2004 03:01:27 -0000
>
>
>
>--- In Homebrew_PCBs@yahoogroups.com, Adam Seychell <a_seychell@y...>
>wrote:
> > Thats not the full story, the regeneration reaction consumes both
>oxygen
> > (from air) and free hydrochloric acid. Overall it is;
> >
> > CuCl + O + 2HCl -> CuCl2 + H20
>
>This doesn't balance. where does the other Cl go?
>
>But the reaosn for my post is a question about this process. I can
>bubble for 48+ hrs and get slow etching ( about 1 hr) but if I add 50
>mL of 35% H2O2 (2.5 L of etchant) it takes about 1/3 the time. Acid
>level look right and SG is getting towards 1.17. I think there must
>be some other reaction taking place - any one able to shed light on this?
Are you heating it? CuCl2 needs to be warm to work properly.
Leon