Homebrew_PCBs

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:

>
> On Tue, 03 Jan 2006 15:48:13 +0100, Bruno St-Laurent <bsl88k@n...>
> wrote:
>
> > Hi guys I'm new using the homebrew mix of HCL 30% and H2O2 3%, and
> >
> > would like to know what is the best temperature for good etch

time??? ,

> >
> > right now when i do a fresh mix, the etch time is really fast

around 5

> >
> > minutes , but if a week later i want to reuse that mix now clear

green

> >
> > color my etch time goes up to more than 30 minutes!!!!!!
> >
> >
> > Thanks
> >
> >
> > Bruno
>
> It is problematic to heat this etchant because HCL will boil at

like 50C

> or something, and already below this temperature the amount of

produced

> fumes will increase greatly. So there probably isn't much to heat

above

> room temperature before things get nasty.
>
> Use a bubbler.
>
> You do know that you need fresh H2O2 each time, as long as your Cu

levels

> are still low?
>
> ST
>

I do use a bubbler !!!, ok, then i need to get concentrated H2O2!! is
it easily available ???