On Wed, 03 May 2006 20:48:38 +0200, Steve <
alienrelics@...> wrote:
> and I think the
>
> oxidized copper comes out of solution and sinks.
It doesn't, for me. copper coming out i mean.
Something like that what you said is happening, yes. I'm not good at
chemistry but the oxygen in the H2O2 or air combines with the hydrogen
from HCl and leaves Cl to make CuCl2 from Cu2Cl2 (or something like that,
the green stuff from the brown stuff anyway).
Because you could also regenerate CuCl with chlorine gas (if you are keen
on fatal accidents). So my thinking is the HCl and H2O2 is really only
delivering chlorine atoms.
The growth of CuCl is very slow, if you only do a couple of boards every
now and then almost not noticeable.
You could try to reduce growth by electroplating the copper out, i tried
that a while ago with carbon electrodes and a wire to plate onto. It
works, but it is difficult to avoid chlorine bubbles forming on the
electrode (which is what is happening because you take the copper away
from CuCl i assume). The chlorine should not build a gas, it should grab
hold of some copper from the brown stuff to form two green stuff, but
that's not always happening apparently. maybe something like the apparatus
used by fishkeepers to dissolve CO2 into water would help. basically a
tube filled with marbles through which water is pumped, downwards. On the
bottom a very small stream of CO2 bubbles is introduced. As they rise
against the current and bump into the marbles the gas is dissolved. One
should be able to set this up with a electrode at the bottom fairly
easily, but since the growth is really so slow i never bothered to even
try.
ST