This is the one i bought:
<http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=230309376059>
I wish it had a scale just for specific gravity, down to 1.0. I don't
really care about the antifreeze scales.

1.2 to 1.4 is pretty much the range you need, and 1.0 to 1.2 is
interesting while you grow the bath. Luckily car battery acid operates
in the same range which gives us easy access to cheap hydrometers.

You MUST read these two documents from the links sections, these are
the ones where the link still work:

<http://members.optusnet.com.au/~eseychell/PCB/etching_CuCl/index.html#analysis_\
SG>
By our very own Adam Seychell, probably the best document about
homebrew CuCl you can find.

<http://www.xertech.net/Tech/CuCl_ech.html> Also quite interesting.

Which should also answer your question about stating quantities.

ST



On Tue, Jan 6, 2009 at 12:51 PM, Markus Zingg
<homebrew-pcb@...> wrote:
> Stefan,
>
> Thanks for your information. Still some more questions :-)
>
> - Can you give a ratio to at least start? I mean how much HCL and H2O2
> should I use for the first "run"?
> - Do you have a link to the refractometer? Cause at that cost, I
> probably also would apreciate to avoid the mess involved with a hygrometer.
> - what refraction coefficient or fluid density ranges would be good for
> etching?
>
> Since I'm only makeing prototypes, I don't mind if cucl is not that
> fast. The Fe3Cl I used so far is also not that fast after a couple of
> boards. I'm more after a solution which etches evenly and where I don't
> have waste to dispose thereafter (or as few as possible).
>
> Markus
>