Homebrew PCBs

The solution does get darker as more copper is dissolved, but slightly
green doesn't mean there is anywhere near enough copper to etch a
board.

If you want to measure this, you can get a hydrometer. The ones sold
for car battery acid checks will usually do. A refractometer should
work as well.

Or you can just keep on etching and not worry about it, one day it
will be strong enough to make a board without adding any H2O2.

If this feature is very important to you just throw some scrap copper
in and etch it away, that'll rapidly increase the density.

ST

On Mon, Jan 5, 2009 at 5:25 PM, Wayne Topa <linuxone@...> wrote:

> Ah Ha, the rejuvination process, adding H2O2 before each etching
> session, until it becomes
> CuCl.  Is that the stage where the solution changes color?
>
> Thanks guys for refreshing my ageing memory.
>
> Wayne
>
>