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Copper surface protection: benzotriazole vs. dichromate

Q. I am making copper garden accessories. I am doing this on a small scale now in my garage, but expanding my sales gradually. I want to protect the new copper look for a few weeks after I make the items. I don't want permanent protection (sprayed with something like Incralac ⇦this on eBay or Amazon [affil links] ), just some extra corrosion inhibition.

I understand I could use benzotriazole ⇦this on eBay or Amazon [affil links] or sodium dichromate to protect the surface for some period longer than bare metal so I am not continually cleaning the surfaces. Can you compare the protective effects of these 2 treatments.

Thanks,

John R.
- Sandusky, Ohio

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A. The protective value of benzotriazole is that it probably won't land you in jail like dichromate :-)

Seriously, it is one thing to spray paint your own hobbywork in your garage, but something else to sell something that you processed with hexavalent chromium in your garage. Don't even think about it. Or if you insist on thinking about it, start with EPA CFR433.

I think dichromate will give more real protection, but that the finish will be very dull, whereas benzotriazole will retain the bright reflective look of the copper.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey