--- In
Homebrew_PCBs@yahoogroups.com, Russell Shaw <rjshaw@...> wrote:
>
> On 23/03/12 02:07, sheldon_mp_cooper wrote:
> > --- In Homebrew_PCBs@yahoogroups.com, Russell Shaw<rjshaw@> wrote:
> >>
>
> >> The deep olive colour is when to add HCl and use as a long-term etchant.
> >
> > But, at that point, highly dangerous chlorine gas WILL be generated from the
> > reaction, as was warned about in the other link I referred to where the gent
> > said he'd used the same etchant for four years.
>
> Adding a cup of HCl to a litre of spent or unspent ferric chloride will cause absolutely no outgassing whatsoever.
Well, I guess you must be speaking from experience and I haven't done this myself, but this gent who has says it will:
http://www.qsl.net/iz7ath/web/02_brew/14_howto/02_clor/index.htmExcerpt:
"It's necessary to regenerate it;
1)At first it's necessary to raise the acidity, adding hydrochloridic acid HCl (you'll find at shop as muriatic acid, mixed with water.....ask mum); make this work in a open place (DANGEROUS GAS) addig HCl until the muddiness in the tank disappears (or you can also use a litmus paper)."