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Sealer for heat colored copper

Jewelry Discussion
#1

Roseann,

I work in copper and have used heat coloring for years. I have not,
however found a satifactory sealer that retains the brilliant
color. I have tried waxes, a wide variety of lacquers and clear
sealants. It seemed as if every sealant reacted with the copper and
changed or dulled the color. The sealants that reacted the least
with the copper were water-based polyurethanes, if I remember
correctly. The difficulties I had with sealants have discouraged me
from using them on my work, especially if I want to retain the
brilliant fushia and blue.

Dianne

#2

Diane,

I have been doing an Iris sculpture using a fold-forming technique.
I use heat coloring to get the colors on the blossom. Are there any
special tricks that you would suggest that would let me get more
blues on to the piece? I get small spots of blue color but have not
been able to get a more even coloring. I have experimented with soft,
bushy flames and sharp, hot flames. No real control has developed
yet. I also realize that experience has a great deal to do with this
trick. Any comments would be gratefully appreciated.

Bill Churlik
@Bill_Churlik
www.earthspeakarts.com

#3

I had the same experience of nothing working that retained the colors
I wanted. Then I took a workshop with Ed Gray
http://www.edgraystudio.com

Ed taught us to apply diluted Harris silver soldering flux all over
the piece before drawing the color with a torch. That seemed to make
the color “stick” so it could withstand a varnish or lacquer. This
was years ago and unfortunately I don’t remember about cleaning off
the piece afterwards. Seems as if the pickle would take off all the
color but I just don’t remember for sure. I do remember that his
process works. Perhaps an email to Ed would reveal the final steps.
He’s a very kind man and a wonderful artist.

Catherine Jo Morgan http://www.cjmorgan.com
online artist journal, Hand Forged Vessels:
http://radio.weblogs.com/0120691/ energyart@cjmorgan.com

#4

The colors on a heat patinaed surface are produced by a varying
thin film oxide layer. The film thicknesses are about a wave length
of light or only a few atoms thick. On some materials that have
stable oxides like chromium rich stainless steel surfaces the color
effect is quite hard and very durable unprotected. On other
materials like copper and sterling silver the material is subject
to reaction with atmospheric contaminants and oxygen. They are very
susceptible to trace sulfur compounds, ammonia type compounds ,
moist carbon dioxide and also the oxide layers can change with time
and exposure. These are the stuff on the natural patina on old
bronzes. But acid rain ruins these. The original heat oxide
colors are also soft compared to the chromium oxide on stainless
steel Result easy to wipe or polish off. Protecting them for a long
period is an exercise in futility. Covering them with lacquer
swamps the film effects into mud because the lacquer film is so
thick. Waxes can be applied thinner but the film effect will change
an the colored layers can still be polished off. I have posted a
bunch of stuff on the film interference layer colors. some of it is
complex to understand - the soap bubble stuff brings it more into
reality. look maybe learn- don’t feel bad if it is hard to grasp you
are not alone.

http://acept.la.asu.edu/PiN/rdg/interfere/interfere.shtml

http://hyperphysics.phy-astr.gsu.edu/hbase/vision/specol.html#c1

http://online.cctt.org/physicslab/content/PhyAPB/lessonnotes/twosourceinterference/thinfilminterference.asp

http://www.exploratorium.edu/ronh/bubbles/bubble_colors.html

#5

I have coated heat colored copper with Krylon Crystal Clear Acrylic
Coating # 1303 years ago and they are still fine.

Joel Schwalb
@Joel_Schwalb
www.schwalbstudio.com

#6

Bill, Donna & Diane,

I put my items on a hot plate and warm them very very slowly. I will
sometimes turn them over and around so that it heats evenly. It take
a lot more time to go through the colors an a lot more patient’s
this way. Start out with the hot plate on a low temp setting and see
how that goes. While the item is hot, I use pure bees wax in stick
form and wipe it onto the item. Don’t allow it to get too thick,
then the color dulls. I spread out the wax using a pure sable paint
brush. Do not use any other kind as the plastic kind will melt and
adhere. I was shown this technique by a bronze artist.

I hope this helps
Janet Alexander
http;//www.ornettes.com
(newbie to this forum)

#7 
I have recently seen copper objects with head patinas powder
coated clear that look pretty good. The color was knocked down a
little but not as bad as other coatings I have seen.

Another local artists uses Incralac spray on heat colored shibuichi
with good effects and pretty long wear.

Bill