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

----- Original Message -----
From: "Howard" <hj.payne@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, June 04, 2008 3:53 PM
Subject: [Homebrew_PCBs] HELP: Ammonium persulfate


> Hi all
> X-Antispam: NO; Spamcatcher 5.0.12. Score 2
>
> Now i have been out of making Projects and PCB'S for some yrs now
> and have just got back into doing it, god what have i missed ?.
>
> I need to make about 3 ltrs of this to use in my PA104 etch tank.
> Now my dad used to use this stuff ages ago (15yrs), but sadley
> he's no longer with us!. I think as i can remember he used to put
> a bit of salt in his mix, to give it a bit of a kick!!.
>
> Anyway what i am wanting to know is, how meny grams of Ammonium
> persulfate do i mix to 3 ltrs of water, to etch Fotoboard 2 pcb ?
>
> Also is caustic soda ok to use as a developer for Fotoboard 2 ?
> and to make 1 ltr how meny grams to mix with water ?.

I used ammonium persulphate may years ago, but I've forgotten the
concentration. I used to add some salt to speed it up. I think that mercuric
chloride was recommended as a catalyst, but it's very toxic.

12 g /litre of NaOH is what I use for developing Fotoboard 2 (it's about two
teaspoons).

Leon
--
Leon Heller
Amateur radio call-sign G1HSM
Yaesu FT-817ND transceiver
Suzuki SV1000S motorcycle
leon355@...
http://www.geocities.com/leon_heller