If you put some iron or steel in the CuCl it gets a copper coating.
I dunno what happens here, i expect it is some form of electroless plating.
But i think in your case something different is happening, since the CuCl
copper coat on iron is thin and mostly smooth.
If you want to get the aluminum black you can anodize it and use black
color with that. Seems quite easy to set up at home, although i didn't
find enough need so far.
ST
On Fri, 07 Apr 2006 15:55:54 +0200, lcdpublishing
<
lcdpublishing@...> wrote:
> 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