Homebrew PCBs

On Thu, 23 Feb 2006 03:13:57 +0100, wbblair3 <wbblair3@...> wrote:

> (and it's
>
> _opaque_ which brings up the question of whether or not a premixed
>
> solution of CuCl etchant in storage should be kept in an opaque
>
> container or at least in a dark area to prevent decomposition of the
>
> H202).

The H2O2 mixed with acid and metal traces will decompose anyway, which is  
why you mustn't have a tightly closing lid or the bottle can explode. Back  
in the days before i had a permanent etching tank i had a bottle with a  
tiny hole made in the cap. I glued a smaller cap on top of it, with  
another hole, and filled the space between with open cell foam rubber.  
This way it won't leak fast even when tipped over.

> of, I looked up PET at Wikipedia and found this:
>
>
> http://en.wikipedia.org/wiki/Polyethylene_terephthalate
>
>
> Stefan also stated that this was the type of plastic used in the
>
> chemical manufacturer's original HCl containers, so the thick-walled
>
> variety must be OK to use for CuCl etchant.  My 259ml water bottles
>
> and 2 liter soda bottles are PET and are marked PETE (#1), but are not
>
> thick-walled.


PET is _NOT_ originally used, PE is, HDPE from the feel of it.
PET will be ok, but form salts on the outside and become cloudy quicker.

ST