Subject: Re: Copper Patina Recipies

From: [email-masked] (Cynthia5)
Date: 21 Jul 1996 10:07:11 -0400

Copper is very easy esy to patina unless you want to get into the red
colors.  They are the most difficlut.  There are several good books on the
market.  Try Ronald Young's books--one is Methods For Modern Sculptors. 
Also, "The coloring and Patination of Bronze" is great tho a very
expensive book...and highly toxic in terms of chemicals needed to get the
patinas.  
Some safety precautions regarding patination:  do it in a well ventilated
area.  Always wear latex gloves, a respirator with metal fume filters and
safety glasses.  When you're done, take off the shirt or jacket you're
wearing and if you've got kids, don't let them touch your clothes.  Some
of the stuff is highly toxic.
For a starting patina you might try this.  Its inexpensive and safe.  Get
a 5 gallon buck (or container that will hold the piece you want to color. 
Lay a brick or two in the bottom of it.  Pour is a cup or half cup of
household ammonia.  Set your piece on the brick/s and seal the container. 
Leve it for a few days and check the color.  You should get rich
blues--turquoise to Prussian blue.  When the color is what you want,
remove it from the container.  Wear gloves.  You don't want to get oil
>from  your hands on the piece or knock the patina off the surface of the
metal.  Its (the patina) very fugitive at this point.  You'll need to seal
the metal.  A spray can of matte finish for charcoal drawing works well. 
It doesn't diffuse the patina as much as wax or laquer.  
Keep in mind that patinas are very unpredictable.  What you get one time,
you may never get again.  And when you seal the work, you'll lose some of
the intensity of the color.

Cynthia  (Cynthia5 @ AOL)

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From: [email-masked] (James Owen)
Date: Mon, 22 Jul 1996 01:51:02 GMT

Patina for Copper
=============
ratios by parts refer to weight .
---------------------------------------------------------------------------------------------
Green:
Sodium chloride			37  parts
Ammonia water			75 parts
Ammonium chloride		37 parts
strong wine vinegar		5000 parts

Mix and dissolve. apply to object to be treated with camel hair pencil
repeat until the desired shade is reached.

---------------------------------------------------------------------------------------------

Yellow green:

Oxalic acid			5 parts
Ammonium chloride		10 parts
Acetic acid 30% solution		500 parts

---------	or  --------	

Potassium oxalate, acid		4 parts
Ammonium chloride		16-17 parts
vinegar containing 6 % acetic acid	1000 parts

use these as the first formula
---------------------------------------------------------------------------------------------
Bluish green:

use the green formula ( the first one) then use:

Ammonium chloride 		40 parts
Ammonium carbonate		120 parts
water				1000 parts

---------------------------------------------------------------------------------------------

Greenish Brown:

Potassium sulpheret		5 parts
water 				1000 parts

Mix and dissolve. With this coat object to be treated, let dry, then
cover
 with 10 parts a mixture of a saturated solution of ammonia water and
acetic acid
and 5 parts of ammonium chloride thinned with 1000 parts of water.
Let dry again then brush off well. repeat if necessary.

---------------------------------------------------------------------------------------------

Another blue green:

corrosive sublimate		25 parts
potassium nitrate 			86 parts 
borax				56 parts
zinc oxide			113 parts
copper acetate			220-225 parts

mix and heat together on the surface of the object to be treated.

---------------------------------------------------------------------------------------------

Brown:

Potassium oxalate, acid		3 parts
Ammonium Chloride		15 parts
water, distilled			280 parts

Mix and dissolve, apply and let dry. repeat (this is a slow process
but makes an elegent finish)

---------------------------------------------------------------------------------------------

Another green:

Take tartaric acid, dilute half and half with boiling water, coat
object and allow to dry. the next day rub
the applied layer off with oakum, (The coating must be done in DRY
weather to work)
Take hydrochloric acid and dilute it half and half with boiling water
(pour acid into water not vice versa! as it is dangerous) In this
dissolve as much zinc as you can. Allow to settle. Then dilute in half
again with boiling water. Coat the copper with this a few times.

---------------------------------------------------------------------------------------------

Black:

Coat with tallow , light with a torch, wipe reliefs and let dry.

---------------------------------------------------------------------------------------------

Blue-Black:

Use a dilute solution of chloride of antimony in water and add a
little free hydrochloric acid.
apply with a soft brush and allow to dry- then rub with a flannel.

--- or ---

Use a solution of chloride of palladium after cleaning the dirt and
grease off with a hot solution of carbonate of soda

---------------------------------------------------------------------------------------------
Red:

Heat to red-hot,(this makes the copper become cupric oxide on the
surface and cuprous oxide underneath.) after cooling remove the black
cupric oxide with a polishing plate to leave the red cuprous oxide.

You can create a marbled surface by sprinkling borax or some  other
chemical having a similar action on the metal during the heating of
the metal. this prevents oxidation and retains the original metallic
color. you can then use another coloring process.

---------------------------------------------------------------------------------------------
James Owen <[email-masked]>

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From: [email-masked] (James Kirkpatrick)
Date: 23 Jul 96 09:33:14 MDT

In article <[email-masked]>, [email-masked] (jim) writes:
|>I am working with copper and am in need of some recipies to patinate
|>my pieces.
|>
|>I would also apreciate any help in locating vendors of said patinas.

There is an extensive discussion of patinas in the FAQ.  For example, see
http://plains.uwyo.edu/~metal

Jim

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From: [email-masked] (T Wish)
Date: 25 Jul 96 05:31:08 -0700

Kits for Patina are available through arts and crafts stores, perhaps 
through Home Depot and larger hardware Stores, and through the 
Pottery Barn.

Also try the Metals Handbook, Vol. 5 Cleaning and Finishing,(from 
ASM) for recipies.

Tom