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

Does anyone use sodium persulfate as etchant?
I'm makeing my first pcb using toner transfer from kodak-paper. But the
etchant doesn't work very well.
I use about 0,8 dl etchant for 4 dl of water@ca 50° in a plastic bowl
that and moved stirred it pretty much the first hour... The pcb is
about 4x3 cm big.
Now it has been in the etchant all night and only about 1/8 of the
board has etched.
Maybe the kodak-paper left something on the surface? I did iron it
about 60 seconds on both sides. To long?

/P.O.