I seem to remember needing to bubble air through it and/or prime it with copper wire ..... before using it to etch boards ....
you didn't just mix and go for it?
To:
Homebrew_PCBs@yahoogroups.comFrom:
davec2468@...Date: Sun, 27 Nov 2011 08:29:57 -0800
Subject: [Homebrew_PCBs] Re: Sponge etching with HCl and H2O2?
>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?
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