I would like to switch to cucl for a while cause having a solution that
lasts virtually for ever seems to be very beneficial. Besides, I'm just
before building a new etching tank and thought that this would be a good
moment for a switch of the etchant too. Since english is not my native
language, I always felt a bit unsure if I understood things correctly if
you guys were talking about cucl in the past, and there were always some
open ends. In particular the following things are not yet clear to me:
So, one would i.e. need to build 3l HCL/H2O2 and put in half a pound of
copper into it? Correct?
How many HCL and H2O2 to get to a 3l solution to start with? I mean
what's the ratio of HCL to H2O2?
Any restrictions regarding the kind of copper? I do have copper left
over that I use for the anodes in my through plating station. Would that do?
Then, Stefan wrote " If you want to measure this, you can get a
hydrometer. The ones sold for car battery acid checks will usually do. A
refractometer should work as well."
A hydrometer - when useing google - seems to be a device to measure
humidity? Correct? What is a "refractometer", which of the two would be
easier to get and where, and how would one measure what? Regarding the
"air stone bubbler", I think I remember that one uses this to regenerate
the solution. If so, does one have to do this every once in a while, or
only during etching, or just before?
I'm sorry if these are dumb questions, but since working with chemistry
might be dangerous I want to be very sure I understand things correcly
bevore I start to experiment.
TIA
Markus
DJ Delorie schrieb:
>
>
> "Stefan Trethan" <stefan_trethan@...
> <mailto:stefan_trethan%40gmx.at>> writes:
> > If this feature is very important to you just throw some scrap copper
> > in and etch it away, that'll rapidly increase the density.
>
> This is what I ended up doing - I wasn't using the HCl/H2O2 solution
> often enough and had to keep evaporating off water to fit in more
> H2O2, so one day I just dumped about half a pound of copper into the
> bucket and let it dissolve over a couple of days. ∗Then∗ I dumped in
> some H2O2 to "charge" it (it turned from brown to green) and it's been
> stable since then.
>
> At this point, my solution is so dark green that you can't see the pcb
> when you're etching it. Etching takes about 5-6 minutes, plenty fast
> enough for me.
>
> I calculated the ratio at about 1 lb copper to 3 l solution.
>
>