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

I have a commercial etching tank, composed of formed acrylic plastic
and two fish tank pumps.

It's designed for sodium persulphate etchant.

I can get a pool shock persulphate etchant for about 10 dollars for 1
KG, and you need about 1 KG for a single run (no idea how many boards
that is, but it's about 1-2 gallons of etchant).

The normal HCl/H2O2 etchant that I use would no doubt eat the pumps to
pieces.

So a question would be: Can I use high concentration H2O2 (say from a
beauty supply store, no idea how much that might be, but presumably
less than the 1.25 dollars/quart that I can get H2O2 for...)? Just by
itself, I suspect that it might not work, would activating that
etchant with a little chloride ions (perhaps salt?) work?

Has anyone looked for a substitute for Sodium persulphate (potassium
persulphate will also work, but equally expensive, I think)?

Is there an etchant that will work for this kind of situation?

Harvey