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Coloring copper


#1

i was reading my copy of van neumann’s “design and creation of
jewelry” & decided to try his recipe for achieving a brown color on
copper

“one part copper sulphate (i bought “Blue Vitriol” listed as copper
sulfate) and two parts water” i used hot tap water, as i would using
liver of sulfur,and found-no change at all on my copper wire- i even
left it in over night, though of course it didn’t stay hot any
suggestions?

Joanne Davis-Woods
enthusiastic newbie


#2

I would suggest that you try some cold bluing compound for
gunsmithing. It is a mixture of Nitric and selenious acid with copper
sulphate solution. Used by model engineers on copper to get a
brown-black so just keep an eye on it as it works pretty quickly.

Nick Royall


#3

Did you per chance notice if the end of the wire colored? That would
have been clean fresh metal from the cut. Is your wire coated? Sand
or scrape an area and see if it colors. RMS has Baldwin’s Patina it
is designed to produce and old penny brown on copper.

Bill

Bill, Deborah, Michele & Sharon


#4

Haven’t looked for a brown on copper (yet) but I read that you must
clean the copper well and apply the solution you tried with a
scrubby pad to work up a bit of a tooth. As I say. haven’t looked for
the effect yet.

Barbara


#5

A funky old and very cheap method I was taught at the Appalachian
Center for Crafts is:

Take some cheap peanut oil and rub on the piece you wish to be brown.
Then wipe it all off as best you can with a paper towel. Really work
at wiping it off too!. Then place it in an oven at 200 degrees F.
That is the warm setting on most ovens. (household cooking type).
When you think about it, it is the oils in our skin that causes the
pennies to turn brown. I also found by doing successive coatings it
gave different browns. Time in the oven is dependent on how long you
can stand to wait. The longer the browner as well.

Aggie, The old lady in FL with medical proof that I’m a PIA


#6
Take some cheap peanut oil and rub on the piece you wish to be
brown. ... When you think about it, it is the oils in our skin that
causes the pennies to turn brown. I also found by doing successive
coatings it gave different browns. 

Sort of. The oxidation of the pennies isn’t from oil in the skin, but
rather the salts, plus moisture (like perspiration…)

The peanut oil finish is one I first saw experimented with at
Cranbrook in the 70s. Then, we’d spray it on while gently heating
with a big annealing torch. It was, at the time, inspired by
japanese metal finishes. But I digress… What is browning with the
peanut oil is not the metal. It’s the oil itself oxidizing and
solidifying to a sort of varnish-like surface coating. That’s why
successive coats give a darker color. You can think of this a little
bit like what happens with a well cured wok. The steel hasn’t turned
that nice dark color that indicates a well seasoned surface, (which
if you’ve used one, is almost as non-stick as a teflon pan, so long
as there is also a trace of oil there again in cooking.) It’s the
repeatedly oxidized and built up layers of the cooking oil you’re
looking at. In the peanut oil finish, the tricky part is to get it
even. That’s why Agnes learned, and is passing on, the need to rub it
off, which leaves an even thickness thin film. If the oil layer is
thinner and thicker in various places, then the color won’t be even.
Multiple thin layers work better, are more durable, and look better,
than fewer thicker applications.

Peter