Here's a web page about using the acid/peroxide etchant. About half way down the page is a calculator for the mix. Input your % acid and % peroxide and it tells you how much water you have to add.
http://www.dr-lex.be/hardware/tonertransfer.html --- In Homebrew_PCBs@yahoogroups.com, DaveC <davec2468@...> wrote:
>
> >31% HCL, also known as Muriatic Acid. A standard strength I buy at
> >just about any hardware/building supply store. Also available at
> >pool supply stores.
>
> I'm using the same effective ratio. My muriatic is 15% and h2o2 is 3%
> and my ratio is 1:1.This is the same as you're using: 31% hcl and 3%
> h2o2 at a ratio of 1:2.
>
> I'm still not sure why my etching takes so long.
>
> > > >I've also tried 1 part HCL and 2 parts 12% H2O2 but the reaction was
> >> >too fast and hot to control easily.
>
> I'm confused: you use LESS hcl and the reaction was faster? I thought
> the acid is what increased (using more) or decreased (using less) the
> speed of the reaction, no?
>
> Thanks,
> Dave
>
> -=-=-=-
>
> >--- In Homebrew_PCBs@yahoogroups.com, DaveC <davec2468@> wrote:
> >>
> >> What strength hcl are you using? The ratio is easily understood, but
> >> it all depends on the strengths. (I see you use 3 percent h2o2.)
> >>
> >> Thanks
> >> Dave
> >>
> >> -=-=-=-
> >>
> >> >I use this technique all the time. I can do a 4X6 inch board in
> >> >about 2 minutes. I use 1 Part HCL and 2 Parts 3% H2O2. I make just
> >> >enough etchant to cover the board about 1/8 to 1/4 inch and lightly
> >> >brush the surface with a foam Paint brush. I etch at room
> >> >temperature. Works very well for me.
> >> >
> > > >I've also tried 1 part HCL and 2 parts 12% H2O2 but the reaction was
> >> >too fast and hot to control easily.
> > > >
> >> >
> >> >
> >> >--- In Homebrew_PCBs@yahoogroups.com, "tda7000" <Tda7000@> wrote:
> >> >>
> >> >> I see some people get very fast etch times with a sponge and
> >> >>ferric chloride...
> >> >>
> >> >> But has anyone tried that method with the HCl and H2O2 solution,
> >> >>or the cupric chloride?
> >> >>
> > > > > Or anything else for that matter?
>