3. Now place your scrap metals on the panel’s
surface; the end result is that stains and pitting
will appear on your panel. Arrange the scraps to
create interesting patterns and shapes (though
you won’t know exactly how it turns out until it’s
done). Copper scraps make dark stains, and other
metals create other colors. The longer the metals
are in contact with your panel, the more pitting
occurs. Sprinkle coarse salt over the surface,
and then pour enough vinegar on the surface to
dampen the salt and the panel (Figure 14.3).
CAUTION: Don’t use a spray bottle to apply
the vinegar—it’s nasty if you breathe it in.
I recommend doing this outside to avoid any
fumes in your studio as the panel bakes.
4. Without moving the scraps, wrap up the panel
and scraps in the plastic sheet, or close the plastic
bag loosely (don’t seal it—you want it to dry out),
and let it cook in the sun for several days. The
longer it bakes, the deeper the pits will be. From
now on, wear gloves to handle the panel to avoid
fingerprints on your image later on (Figure 14.4).
5. After the metal panel and scraps are completely
dry, unwrap the package and carefully lift off the
scrap metal. If the panel has not aged enough,
sprinkle on more vinegar and rewrap the scraps
for another day (the salt won’t have evaporated,
so you don’t need any more). Once you like the
effect, it’s time to clean the panel (Figure 14.5).