Torch coloring copper

I’m working with coloring copper with my torch and am getting great
blues, purples and greens as well as golds. When I try to stabilize
the colors using artist spray lacquer like is used on charcoal
drawings or using wax I loose all but the gold shades. Any
suggestions for keeping the wonderful blues etc?

Thanks

Torch colors are interference colors caused by light refracting
through transparent layers of copper oxide. By placing a coating over
it you change the refraction path and the color. So you can never
truly capture/preserve those beautiful colors with any coating.

James Binnion
James Binnion Metal Arts

the oxide colours are there because of the way light passes through
or is reflected from a particular surface. When you laquer your
coating you are changing the way light is behaving with your
material and losing that particular colour you wish to keep. Other
than trial and error with these torch colourings and then laquer I
can suggest you patinate by using chemicals as the effects will
normally be more enduring.

A couple of things to try are ammonia (.880 ammonia) and cold bluing
compounds designed for gunsmiths. These contain nitric and selenious
acids as well as other stuff and this will give an interesting
patination to your copper. Different brands vary in their composition
so try a couple of different ones.

Nick Royall

The difference is that you are creating thin film interference
colors not pigment. You are covering up this angstrom thin color
generating oxide with what amounts to a great thickness of semi
clear paint. Your interference film is simply blanketed in fog.

Bill
Reactive Metals Studio, Inc

There is a local artist here that creates beautiful heat colored
copper panels. They are sealed, so I asked at the time how they
managed to keep the colors (I can’t remember if there was any
magenta, but she definiately had lots of beautiful blues). They use
powder coating. It’s like a low fire enamel - 400 degrees for about
10 minutes. I haven’t tried it yet, but I did purchase a powder
coating paint gun. You get can a small home version through
eastwood.com or Sears craftsman used to have one, I got mine on
ebay. You can use a conventional electric oven or toaster oven to
heat with. Eastwood has instruction videos you can watch for free on
how to use their system. There’s something about the powder coating
that allows for the refraction of the colors that other coatings
don’t. I’ve tried all kinds of coatings and nothing else has worked,
just as Bill at Reactive Metals has stated. Once I get around to
trying the system out, I’ll post my results for everyone.

Ellen Starr

That’s odd. I did a beautiful bluish green torch coloring on a
bracelet I made out of copper, and I lacquered it using Minwax metal
lacquer (in the black can). I had no problems with the color
disappearing. I wonder why I didn’t but others seem to?

-m

That's odd. I did a beautiful bluish green torch coloring on a
bracelet I made out of copper, and I lacquered it using Minwax
metal lacquer (in the black can). I had no problems with the color
disappearing. I wonder why I didn't but others seem to? 

Sometimes they just get less intense It varies with the color and
the coating. But I guarantee the wax changed the color to some
degree.

James Binnion
James Binnion Metal Arts