Homebrew PCBs

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.com
From: 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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