Homebrew PCBs

On Sun, 28 Jul 2013 23:12:45 +0100, you wrote:

>Here's a slightly odd question... well, it is Sunday night :)
>
>I was thinking about mixing up a cupric chloride etch bath. Thing is,
>while I have a ton of concrete cleaner (hydrochloric acid) and raw
>copper (in the form of old copper wire), I don't have any hydrogen peroxide.
>
>Now as I understand it, the H2O2 is used as a source of free oxygen to
>accelerate the reaction between the HCl and Cu. Out of curiosity, would
>it be possible to start a cupric chloride etching bath by bubbling air
>through the HCl while adding copper (possibly heating the HCl to
>accelerate the reaction)?

This is often considered the best writeup on the subject.
He mentions starting with HCl, Cu, and H2O2, but I've never
found a copy where he completed that section
 He does cover starting with HCl, Cu and air.

href="http://techref.massmind.org/techref/pcb/etch/CuCl2.htm"

Keith Bowers WB4LSJ- Thomasville, NC