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Subject: Re: [Homebrew_PCBs] Re: Ferric Chloride - muck at bottom of tank question

From: "Stefan Trethan" <stefan_trethan@...>
Date: 2006-05-07

On Sun, 07 May 2006 18:07:13 +0200, fenrir_co <fenrir@...>
wrote:

> Be careful with the H2O2, while FeCL3 doesn't cause burns quickly,
>
> peroxide at that strength will. Always mix outdoors and add slowly,
>
> this creates large amounts of foaming and heat.
>


Sounds like a rather wild procedure ;-)
Any gas that is released when adding H2O2 is probably something you would
rather wish to keep in the etchant (like oxygen), so if you get bubbles
that is not always a good thing. At least that's how it is with CuCl,
there you do not want to add so much to cause bubbles to form and heating,
because it is only a waste of chemicals.

I'm not quite sure if i had the choice between nursing FeCl on to last
forever, and starting with clean, fresh CuCl with no FeCl at all, if i
would choose to use any FeCl. I don't quite see the advantage, i mean, is
it actually regenerated or is this only CuCl with some used up FeCl
swimming around in it and making things dirty and blocking the view?

ST