Homebrew PCBs

Never thought of adding acid to it to extend it’s life. When I got towards the end of the etching process I’ve seen ferric chloride start to solidify.


When I worked in an electronics plant we used ammonium persulfate for etching boards. And photo resist I believe Kodak brand.  We would put the negative on the board and expose under a sunlamp for 5 minutes. I forget what the developer was , xylene maybe ?  I have spray photo resist here they made it in both positive and negative types developer is different for each ,believe it was made by gc electronics.





From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
Sent: Sunday, January 03, 2016 3:01 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] My toner transfer experance








On 01/01/16 12:57, MIKE DURKIN Patriot121@... [Homebrew_PCBs] wrote:
>
> works for me ...
>
> What kind of acid ?
>
> I only have Ferric Chloride .... if had it for over 25years. One bottle iv never
> opened.


If you use it and use bubble agitation, keep it stored for next time, and top up
with a bit of HCl hydrochloric or muriatic acid next time it's used. It'll
convert to copper chloride etchant and last many dozens of uses, like years
worth. I have mine diluted 1:1 with water which works well. Keep the container
covered when not in use, to prevent HCl vapour from making things rust.