Rick Fisk wrote:
> I believe the exposed sheet metal in the Bugeye cave was
> originally painted with brown colored primer.
Yep! Actually, rather than a "primer", I believe that "brown" color was
a zinc chromate wash that part of the primer. Far better than simple
primer, the zinc chromate dissolves in rain or high humidity to provide
a passive layer on the metal surface to prevent rust. When the humidity
drops, the zinc chromate "blanket" goes away. Eventually, the zinc
chromate is depleted and the cancer begins to appear. This is also why
when scratched, the original paint revealed a "brown" primer
underneath. HOWEVER, this is what I have been told by someone a lot
smarter than me. (I was too dumb to enroll in P-Chem. and I have sent a
lot of money to that Nigerian banker!)
Buster Evans
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