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I am seeking a method to chemically treat new copper counter tops. I would like to see them in a nice brown bronze patina color can you help. if you could give me a formula to treat the surface it would be greatly appreciated. someone else recommended Liver of Sulfur but i cant' find it anywhere to purchase it. thank you so much

james acevedo
- Freeport NY

Hi, James; hi, Sam. Liver of sulphur is available as a dilute, ready to use liquid, or as a crystal-like solid to be diluted in water, by clicking the banners on the right. Formulas for various color patinas can be found in "The Colouring, Bronzing and Patination of Metals". Good luck.

Ted Mooney, P.E.  finishing.com Brick, New Jersey

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A beautiful rich deep brown can be achieved on copper by using first the liver (correct name:Potassium Polysulphide) which is available from most chemical suppliers. It comes in the form of solid dry stones which are easily dissolved in water. One small stone, about the size of your smallest fingernail will be enough to mix a solution of 600 ml. Put this in a spray bottle and apply to the copper while consistently heating with a gas torch. Then gently rub down the surface with a wet scourer until you have an even light brown colour. Then reheat the surface, this time applying a weak ferric nitrate, this will richen, redden and darken the brown that you achieved with the liver, when you are happy with the colour, coat the surface with either a wax (floor wax is sufficient) or clearcoat.

Mal Louis Wood
sculpture foundry - Australia

July 21, 2008

Hi all,
I have been soaking my antique brass fenders & copper coal bucket (together) in vinegar to bring them up looking like new and using 0000 wire wool to remove any tough bits. However the result has been disastrous !!

I put both copper & brass fenders into a vinegar bath together and the brass has come out copper looking ??? which I can't seem to be able to remove using wire wool or 'peak' cleaner. The copper coal box has a blue/green crystallized coating just above the part that wasn't under the vinegar which again I can't seem to be able to remove.

Any advice great appreciated and needed !!!

Pat Rogers
Hobbyist - Navan, Meath, Ireland

Hi, Pat. Unfortunately you can't put mixed metals in a solution like that. What resulted is the same idea that your high school chemistry taught you in coating an iron nail with copper by putting it in copper sulphate. Fortunately the coating is very thin. You'll have to polish the copper off of the brass, probably with a stronger polish and perhaps a little buffing wheel for your electric drill.

You also can't leave parts sticking partway out of solution like that. You need to put them all the way in or not put them in. Good luck.

Regards,

Ted Mooney, P.E.  finishing.com Brick, New Jersey

Thank you Ted
Any suggesting on what a stronger polish might be or should I use a more coarse wire wool?

Rgs Pat

Pat Rogers
- Navan Ireland

Automotive rubbing compound or cutting compound, which is designed to remove the outermost layer of dull paint, is what I'd try on a buffing wheel for removing this copper plating. I would not use courser steel wool because you may scratch your items.

Of course, another approach, if you want to live dangerously, is to put your copper colored brass fenders back in vinegar, this time with some galvanized roofing nails, and see if the copper will deplate from your fender and deposit on the nails, leaving you with brass once again. It is tricky and I wouldn't guarantee success, but it may be possible.

Regards,

Ted Mooney, P.E. 
finishing.com
Brick, New Jersey