The H2O2 dissipates into thin air in storage, literally. The HCl stays
of course, but is used up as copper is etched and CuCl is formed (the
chlorine is taken from the HCl). That's why you want to add no more
H2O2 than what is necessary to etch the board and regenerate all the
CuCl, the rest is wasted.
Think of it the following way, the more CuCl you have the more copper
you can etch without needing to regenerate. At first you need to
regenerate all the time during etching, but eventually you can do a
few boards before it needs another go.
ST
On Sun, Feb 7, 2010 at 7:40 PM, Brian Lalor <blalor@...> wrote:
> It doesn't? Crap. I thought this was a gateway to CuCl. What makes
> it lose effectiveness?