Homebrew PCBs

I assume your A.P. is in powder form. Use only enough powder to do 3 or
less boards under 4X6 inches. Pour water into a glass tray such as a
casserole dish to about one inch deep. Add A.P., about 3 tablespoons.
Stir until dissolved. Emmerse board and agitate often. With single sided
boards, copper side down. With double sided boards turn over every
minute. If you heat the solution it will etch faster, less than 10
minutes. Solution can be used until it turns a medium blue. Solution can
be cooled and reheated as necessary to use. It is not necessary to
bottle it or cover it if you come back in a week or so to reuse it. A
heat lamp or hot plate can be used to speed up the etching as described
on the website. I heat mine to almost a boil and I can etch a board with
fresh A.P. in less than 5 minutes.
Rick - http://www.pic101.com/pcb

mumin55555 wrote:

>  hallo!
> i just bhought 2 litre of ammonium persulphate, since im tired of
> the mass ferric chloride makes. my only problem is that i have to
> fill a 3 litre tank with the 2 litre i have. can i mix ammonium
> persulphate with water??? and if so- how much water can i use on
> each litre of ammonium persulphate so it will keep working well?
> one more question- what is the shelf life of ammonium persulphate? i
> read that once you heat it up and cool it down it wont work again.
> is that true? and what is the optimal temperature to use ammonium
> persulphate????
>
> thanks a lot
> mumin
>
>