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

> In my Kepro datasheet, it says I can shock the solution by adding some

spent

> Sodium Persulfate so I don't have to wait for it to stabilize.
>
> I had some used solution which was 3 months old that I used to shock the
> bath. I know the shelf life for etching is 3 weeks, but can it still be

used

> to add in adjusting the pH?
>
> I went ahead and etched, but it took forever. I was successful at 12/12,

but

> the etching seem to take 15 - 20 minutes. When I had my techs making proto
> boards, it seemed we could etch in 3-5 minutes with hand agitation. The
> solution was at 105-110 deg F. The board was quite small, and as I use

huge

> ground planes and leave
> dead copper on the board to reduce waste, It seems it should have etched
> close to the 3 minute time frame rather than 20 minutes.
>
> I'm doing tray etching with manual agitation.
>
> Thanks
> Ron
>
>