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Blue patina on copper


#1

Does anyone know a blue patina on copper that doesn’t rub off? I’ll
be your best friend.

Richard Bynum.


#2

Patinas always rub off. Unless of course you seal them with clear
paint. that still does not preclude their tendency to continue to
change over time. Here is one possible solution. I am not familiar
with the chemicals or dangers in their use.Please research well and
use all required safety measures.

Sodium thiosulfate 8-12oz/gal
Lead acetate 4 oz/gal
Water
temperature 200F
Immersion 30-60sec.


#3

Hello Richard,

For making copper and brass blue use this:

6 parts Selenious acid, H2SeO3
12 parts Copper sulphate
2 parts HNO3
1000 parts water.

Degrease your object, and further on I don’t know the trick anymore.
I think it was, to sprinkle the solution over the object which should
be still wet of water. Try this first, If this does not work out dip
the object under the solution. And if that does not give the effect,
heat up your solution. The chemical solution is good I am shore. but
experiment with the application.

Martin Niemeijer


#4

Dear Richard

   Does anyone know a blue patina on copper that doesn't rub off? 
I'll be your best friend. 

As others have stated, all patinas will eventually wear off. Patinas
are just a layer - be it thick or thin - on the surface of the object
and thus subject to wear. It can be protected for an example with
laquer or wax, and this will postphone the wear or - if repeated -
avert it.

I have with success used the following formula (taken from Richard
Hughes and Michael Rowe’s: The Colouring, Bronzing and Patination of
Metals", ISBN0-500-01501-5:

Ammonium Carbonate 300g Acetic acid (10 per cent) 35 ml Water 1
liter

Add Ammonium Carbonate to the water, let dissolve and stirr in the
acid very gradually. Heat the solution to 30 - 40 degr. C. Apply the
solution to the piece gently and with a soft brush, then immediately
scratch brush it. Work on it for a short time and then apply more of
the solution. Remove “pools” of solution with a soft brush or by
blotting with soft material. Allow it to dry in air and wax finish
it. This has worked for me and is by far the simplest of the many
recipees in the book. Let’s hear, if it works for you.

I hope, I’ve gained a good friend here :wink:

Kind regards from autumnly Denmark, where wh have not yet had a night of
frost.

Niels L�vschal, Jyllinge, Denmark
@L_F8vschal
phone (+45) 46 78 89 94


#5

Blue patinas on copper are usually achieved with ammonia fumes,
vinegar fumes, or other such processes. Heating will produce colors
along the brown/orange/red/purple range. The blue may be a reaction
to some other chemical present during your heating process (perhaps
some leftover flux). I have used various fluxes to achieve
different color combinations, but not a consistent blue. For blues,
Tim McCreight has a section in his book which reviews some of the
techniques. You can purchase a patina-producing product from Rio or
other suppliers which will give you a green/blue tint (verdigris),
or experiment on your own along these lines. I have found that
ammonia will give more of a true blue. The metal should be clean.
For a stable finish I usually use my ever-present carnuba floor wax.
Some pieces don’t want the smooth finish produced by wax, so I
leave them natural.

regards,
Donna Blow