Maintaining copper shine

I have a commercial building that is faced with copper. I am using muriatic acid ⇦this on eBay or Amazon [affil links] to remove the oxidation discoloration and do not know what to use to seal it so that it keeps its natural shine. Do I need to use special chemicals as a primer? Will a polyurethane work?

Dr. Colin Gage
- Merritt, BC, Canada

If you de-oxidize the copper with Muriatic Acid, once you rinse it and it dries, it will probably lose its original polish look you desire. The only way I have found to maintain brass or copper in the Toronto area is to hand polish using products such as Brasso ⇦this on eBay or Amazon [affil links] . Solvent clean (alcohol)perfectly, allow to dry and spray apply a two part clear urethane. This will give you about 3 years if done properly. Regular maintenance is required. It is a long term project. The best is to let the copper age to it's nature patina green.

Wayne McKee
- Mississauga, Ontario, Canada

May 15, 2011

Which is the alcohol used to clean copper for shining purpose?
Is it isopropyl alcohol, acetone ⇦this on eBay or Amazon [affil links] Warning! highly Flammable! or methanol [affil links]?
please clear this confusion.

regards

Nirmal Jeswani
wire manufacturer - Mumbai, Maharashtra, India

Hi, Nirmal.

I think you are misunderstanding something. Isopropyl alcohol is used for many purposes, one of them being to minimize haze and salt stains because, unlike water, it will have no salt dissolved in it to dry on the surface. Acetone is useful as a solvent for removing certain types of organic contaminants. But you will not be able to brighten copper products with any of these.

To chemically brighten copper you need an oxidizing acid such as sulfuric acid with hydrogen peroxide added. You could try the search term "copper britedip" or "copper bright dip". Good luck.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
May 16, 2011

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