>Here is a link to a web article where the etching process does indeed use
>household vinegar (with drugstore-strength hydrogen peroxide and table salt.)
I've used this to remove nickel plating from a brass substrate. The
brass was very shiny underneath and I wondered if it was being removed as
well, but I never cared enough to test it on the copper on a pcb.
For anyone who cares, this is what I did:
Start with about two ounces of white vinegar
Dissolve about two tablespoons of non-iodized table salt in the
vinegar
Add about two ounces of plain drugstore peroxide
Stir with part to be etched until the desired material has been
removed.
In reality, it was: slop vinegar into a paper cup to about 1/3 full,
pour two piles of salt in hand and dump in, stir, slop in peroxide to
about 2/3 full, stir with plated part. It went faster than I anticipated.
It might be slow for a pcb, but it has advantages for those who
don't want HCl around the house - the kids can only get into so much
trouble with a bottle of vinegar.
-Gary