Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

----- Original Message -----
From: "mumin55555" <mumin55555@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, April 12, 2004 12:57 PM
Subject: [Homebrew_PCBs] help!!! my ammonium persulphate doesent
work!!!!!!!!!!


> i tried for the first time to use ammonium persulphate instead of
> ferric chloride. i built a nice etcing tank with a heater at about
> 50 degree celcius and an air pump. i used about 1kg of ammonium
> persulphate with 2 litre of water (at the first place i used much
> less ammonium persulphate, but when i saw nothing is happening i put

Many years ago when I used ammonium persulpahate I added a small amount of
salt (NaCl) to speed it up. Lots of nasty chlorine was given off, but it was
very fast. Mercuric chloride was used commercially instead of salt- I think
it acted as a catalyst - but it's very toxic and difficult to get hold of.

Leon