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metal coatings and patination was: re: new ceramic arts magazine

updated thu 21 feb 02

 

Roger Korn on tue 19 feb 02


I'm wondering how patination products would work on bright copper raku pieces?
Anybody tried this yet?

Roger

Snail Scott wrote:

> At 03:01 PM 2/18/02 EST, Marie wrote:
> >hifired@EARTHLINK.NET writes:
> >> there was an interesting ad for metal coatings and
> >> patinas. I want to try that
> >
> >I also want to find out more about this, I went to the website that is
> >listed, but didn't see any info on the metal stuff...
>
> That 'metal stuff' was in an ad from Sculpt Nouveau,
> a bronze casting services and supply outfit. Ron Young
> is affiliated with them, or owns it, or something.
>
> I don't know this product specifically, but it appears
> to be one of a type of product used to simulate bronze
> patinas on non-bronze surfaces. Typically, it's a two-
> part process, starting with a coating of copper-bearing
> paint, then following with chemicals which affect the
> copper in the paint layer in a manner similar to the
> way bronze-patina chemicals affect the copper content
> of the bronze.
>
> -Snail
>
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--
Roger Korn
McKay Creek Ceramics
In AZ: PO Box 463
4215 Culpepper Ranch Rd
Rimrock, AZ 86335
928-567-5699 <-
In OR: PO Box 436
31330 NW Pacific Ave.
North Plains, OR 97133
503-647-5464

Snail Scott on wed 20 feb 02


At 10:05 AM 2/19/02 -0700, Roger wrote:
>I'm wondering how patination products would work on bright copper raku
pieces?
>Anybody tried this yet?



Never tried it but...

Even copper raku glazes are still mostly glass. I doubt whether
anything applied to their surfaces would stick, unless it were
a very matte glaze, and even then, there's probably not enough
free copper to create a chemical patina.

A quick lecture on bronze patina...there are basically two types.

Cold patinas: These rely on the reactivity of the copper in the
bronze. Most alloys for art are about 95% copper. Alloys with
lower percentages are noticeably less receptive to patina,
though a _little_ heat can help with that.

Hot patinas: These rely on heating the surface of the object.
Reactivity of the surface is less relevant, as the effects
are mainly produced by fusing the patina chemicals onto the
surface with heat. With hot patinas, the temperature and the
application process are the governing factors. A very shiny
surface tends to allow the patina to flake off. The temperatures
used are typically in the range of a clothes-iron, where a drop
of water will sizzle away instantly, but not 'jump'.

These 'artificial' patinas advertised by Sculpt Nouveau and
others are not a product I've worked with, though I've seen
them. Some are merely paint. Others lay down a coating of
copper which is sufficient to allow a cold patina to take
effect.

I spoke with the folks at Sculpt Nouveau, and they say that
their product is a polymer-bound copper coating which is
receptive to cold-patina chemicals. It can also be burnished
to a remarkably convincing simulation of actual metal. (It
cannot be used for hot patina work.) It comes in several
colors.

Though my instinct is to say, "If you want it to look like
bronze, then make it out of bronze", I recognize that casting
is not the most accessible process on earth, and a product
like this one does seem to fill a need to make things 'look
like bronze'.

I never thought I was a 'materials purist' but perhaps my
years in the foundry trade has made me oversensitive to
'fake bronze' in all its forms. Certainly I've met many
people who were unaware that 'cold-cast' bronze is in
fact plastic, and who thought that 'bronze' baby shoes
were actually metal, not electroplated, or who thought that
bronze sculpture is electroplated, too. (They ask, "But
what's underneath the metal?") Or maybe I'm just jealous
that the metalworking and patina skills I've acquired over
the years can be so easily made unnecessary. (Kind of like
the throwers who despise jiggerers?) I hope not.

There's a strong modernist streak in the art world even now,
which gives less credibility to work which appears to deny
its actual materials (unless done with ironic intent). These
'artifical bronze' products will almost certainly be scorned
in some circles because of this, and embraced by those who
don't buy that argument. Still, everyone should give
occasional thought to "What is the nature of my materials,
and why do I choose them?"

Maybe I'll order some of the stuff myself.

-Snail