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

Hi guys,

Perhaps one of you chemistry guys knows what happened here. While
etching a board, I got to thinking about how the Ferric Chloride
stains some metals (and wood, and other things) black. Always one to
try things, I dipped an aluminum bar in the stuff for a few seconds.

When I pulled it out, it had what appears to be rust scale on it like
crazy! I assume this to be bits of Copper and not rust, but I was
wondering if someone could explain what happened there? I don't think
it was electrolysis - no electricty going through the mess.

Yet, somehow, the copper seemed to attract to the aluminum - it didn't
stick though. A rinse in water removed it quickly. The aluminum did
turn gray in color and not black like i had hoped - so it was a failed
experiment. But, it sure was interesting and raised a few questions!

Chris