Homebrew PCBs

>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?