Homebrew PCBs

>   Thanks for the info.  From what you said, I read that Ammonium
> Chloride is useful as a flux, but will eat up non copper metals, is that
> correct?  I know it is very water soluble, so washing after forming the
> circuit pattern on the substrate, but before soldering any components on
> should get rid of the corrosion issue.

One of my friends tried that, but found that he was unable to clean it, plus
he also had ionic contaminants that migrated into the laminate. It might be
worth trying a few things, but the cleaning will be critical. As far as
ionic contamination and resulting problems, I'm not sure what to say.
Ron