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

----- Original Message -----
From: "electrophilip" <electrophil@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Sunday, December 11, 2005 11:56 AM
Subject: [Homebrew_PCBs] Etching (time,strength,machine)


> Hello, is there a way of working out the strength of ammonium
> persulphate, I have been using about 5 tablespoons per litre of water,
> I have the temperature as hot as the hot water cylinder will supply
> and it takes about 15 minutes to etch. Are there any plans around for
> a small spray etching setup or could someone point me in the right
> direction for what sort of pump to use.

When I used ammonium persulphate many years ago I used to add a little salt,
that speeded it up a lot. Only problem is that chlorine gas is released,
which is rather toxic.

Leon

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