Homebrew PCBs

On Sun, 25 Mar 2007 13:30:24 +0200, sam_jfs <Samuel_joao@...>  
wrote:

> I use Muriatic acid and H2O2 ( medical grade 3% too ) with good
> results. The only problem is, after some days i can�t really etch with
> it, i must throw it away and make a new one, i don�t know why, i don�t
> understand chemistry ...


The reason is that the H2O2 is not stable in the etchant, it dissipates  
into the air.
You can rejuvenate the etchant with fresh H2O2, but the problem with the  
3% stuff is you would add too much water.
If you can get 25 or 30% H2O2 you can use the same etchant forever.

ST