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Subject: Re: [Homebrew_PCBs] Re: Etchiing with CuCl2 + O2 ?

From: Adam Seychell <a_seychell@...>
Date: 2005-02-12

Phil wrote:

>
>
> My CuCl is about 1.2 SG and is still pretty slow. no amount of
> bubbling regens it. H2O2 make all the difference but its still
> taking abourd 40 minutes to etch a board. The literature I've seen
> seems to say 1.17 is the target SG. I guess I should dump some more
> copper in.
>

If bubbles don't regenerate then your out of acid because ;

2CuCl + O + 2HCl -> 2CuCl2 + H20

note HCl is needed for regeneration.

If you see signs of bright blue copper hydroxide then your defiantly out
of acid. Put a drop on a piece of glass and it should turn from the dark
opaque green to bright green in under an hour due to air exposure. If
not change color then no acid.