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Letter 790
How to antique copper?
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What can I apply to bright copper to rapidly produce the
weathered green appearance? Thanks for any suggestions.
Alan Ziskind, M.D.
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Try Getting it powder coated with a patina or other
weathered look finish. It may save you a lot of money and
hassle.
Jim Cummings
powder coating - Buffalo, New York
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The patina that you wish to apply to copper is a form of Copper
carbonate that usually forms over a long period of time on items left
outdoors. However to speed things up, the metal finisher has mixtures
that can do almost the same thing. I would recommend that you seek
out a lamp restoration shop that does metal finishing and plating.
Any chemicals should be used carefully, and with full protective gear
as is appropriate. One suggested formula is:
Copper Nitrate 4 ozs.
Ammonium Chloride 4 ozs.
Calcium Chloride 4 ozs.
Water 1 Gallon
Parts may be immersed, and the solution allowed to dry on. Repeat.
Another bath used many years ago was a solution of Copper Carbonate
and ammonia. However, due to the fumes from the ammonia, I would not
suggest that you try this.
 
Ed Budman
- Pennsylvania
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Don't know if I can be of any help, but I need help. My
wife has given me the task of finishing copper panels in a
cabinet over our fireplace. The copper is like a new penny.
She would like it to be old penny. Without waiting six
months for it to do it on its own, what can I do? Each of
the ten panels had a design punched in it, like a basket of
flowers, rose bud, act. Save me...!!!
Sam P. Wehunt
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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
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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.
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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
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December 20, 2006
We have just built a bar counter top with copper. I'm want to give
it an acid washed, spotted look. Like something was spilled on it or
like it was rained on. Do you have any ideas on what to use on it?
Gary Zuk
engineering - West Bloomfield, Michigan
February 4, 2007
IT is very simple indeed
wet a cloth with HARPIC ' the toilet cleaner'
wipe the copper
wait for one day
gently wash under running water to wash off the remaining
harpic
do not scrub or rub as that will remove the patina formation
powder
after drying spray with clear lacquer to fix the patina
formation
I have been doing this often to give my copper sculptures a patina
coating
Soumyajit Choudhury
- Indian presently in Dubai
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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
July 22, 2008
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,
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Ted Mooney, P.E.
finishing.com
Brick, New Jersey
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July 30, 2008
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
Hobbyist - Navan, Meath, Ireland
July 30, 2008
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
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September 11, 2008
I'd like to know if there is any easier way than using the
recommended liver of sulfur and heat to antique copper jewelry beads
to give them the dark brown finish. I am trying to antique beads to
use in my jewelry designs and many beads are a brilliant finish
instead on a burnished or aged finish.
Any help would be very greatly appreciated.
Thanks,
Penelope Consales
artist, jewelry maker - Tucson, Arizona
September 18, 2008
Hi, Penelope. If you are buying finished beads they may already be
lacquered, and the lacquer must be removed with acetone or lacquer
thinner. I'm not seeing what's hard about using liver of sulfur: it's
dirt cheap, it's readily available, and it's designed to do exactly
what you're trying to do.
But if you want a "green" approach, put the jewelry in a plastic
baggie with cruahed hard boiled eggs overnight. Good luck.
Regards,
 Ted Mooney, P.E. finishing.com Brick, New Jersey
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