Coating Al and Cu simultaneously
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Aug30-06, 02:58 PM
Bob, here's the blackening solution info I promised earlier:
Ultra-Blak 420 (for copper/brass), from Electrochemical Products, Inc.
Edit: Just tried it out on a test piece. Made a uniform, black coating in about 30 seconds (maybe less) over a 2 inch square plate. Feels pretty stable (does not flake or chip off easily; doesn't scratch with a fingernail), but I have no idea if it's any good for corrosion resistance.
Doubt that sort of thing would be available in my part of the world though.
edit: And what would NaOH do to copper if i didn't take the heatsink apart?