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Subject: Re: [Homebrew_PCBs] Oxygen tablets for CuCl regeneration

From: Adam Seychell <a_seychell@...>
Date: 2009-07-06

Ken Stuempges wrote:
>
>
>
> Howdy
>
> I have this "hare-brained" idea on another method to regenerate Cuperic
> Chloride etchant. I plan on getting some "Oxygen Tablets" (used in fish
> tanks, live bait tanks, etc), and placing one of the tablets in a closed
> container of water to generate oxygen.
> The container will be connected via a tube to my bubbler, rather than my
> air pump. As a result, pure oxygen will be bubbled, rather than air. I'm
> guessing that it should be as fast a regenerator as Hydrogen Peroxide .
> . . and not any more expensive when compared to 30 or 40 volume Hydrogen
> Peroxide - plus the etchant will not be diluted.
> Any comments ? Has anyone tried this? I'll post my results
>
> Ken
>

I don't see why it wouldn't work. A bit expensive though for what you
might possibly gain in relation to regeneration speed compared to room
temperature air bubbling.

Are you having trouble with air regeneration ?
Is the acid high enough ?

The solution doesn't have to be bright green in order to etch. Its
difficult to specify, but etch speed only slows down when its "really
dark brown". If you take a tank sample in a test tube, dilute ~10:1 with
water and if you don't see any visible signs of white precipitate then
the copper(I) chloride is below limits and should etch ok.

Adam