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Subject: Re: [Homebrew_PCBs] Shelf life of HCl/H2O2

From: Wayne Topa <linuxone@...>
Date: 2009-01-05

DJ Delorie wrote:
> "Stefan Trethan" <stefan_trethan@...> 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.
>
>

Thanks Stefan and DJ. That is what I remember (now), that I read a few
years ago. I
believe that it was you fellows that got me interested in the first
place to try this.


Stefan, was it you who kept your CuCl in a double capped bottle with
small holes in each
"plastic?" cap to slow down the evaporation of the H2O2? And do you air
bubble the
solution?

DJ, do you keep yours CuCl in a rubbermaid kitchen container, with a
lid on it? If so, do
you air bubble the solution?

Thanks for your replys.

Wayne