Copper powder inclusion

[Terry Gallentine]

I am interested in using copper powder in my work and I was wondering if anyone out there could help me with a couple of questions. I have already tried mixing the copper powder with the glass flux that I normally use with ceramic stains but I find that it is not stable and results only in a light turquoise color being produced. The second thing that I tried was to paint the copper powder on the glass and then sift powdered frit over it. The result was the copper was stable but turned black. What I am trying to achieve is a bright copper powder inclusion. I know that there is a book out there by Boyce Lundstrum that covers some copper inclusion techniques but I don't know if it addresses powder inclusion (especially with the results being a bright copper). Does anybody out there have any experience with this or have any suggestions for me where to look for more information?

[Kevin Midgley]

http://www.boycelundstrom.com
Materials for experimentation and exploration.

[Andre Zunino]

Copper is going to react in different ways depending on your firing schedule and I would guess potentially what glass it is fired on (i.e. are you getting a reaction because the glass you are sifting the copper powder onto contains sulfur?). When we use copper inclusions, colors can range from copper to reds to dark blue. Copper that is exposed to the atmosphere in the kiln the longest seems to have the most reaction, turning a deep blue color, while the copper that is exposed the least, usually in the center of the glass piece seems to stay more coppery colored.

[Terry Gallentine]

I am using system 96 for my base glass and powdered frits. The glass flux that I use is a lead based flux.

[Andre Zunino]

Sorry, most of my experience is with Bullseye glass. With Bullseye if a glass color containing copper come Ito contact with another glass color containing sulphur, you can sometimes get a reaction which can in some cases be very dark. I would assume the same reaction could also happen with System 96. According to the Bullseye chart lead and copper do not react, so your flux may not be the issue.

I know that when I am firing copper, if I have a long bubble squeeze in the 1150-1225 range for say an hour or so, that it will tend to darken my copper more than if I choose a shorter time. Again this seems to be related as to how long the copper stays exposed to the air during firing.

I know that Lundstrums book talks about using boric acid in a water solution and painting it over the copper to keep it bright and shiny, but in his examples he is using copper sheet, so I don't know how practical that would be over copper powder.

[Stephen Richard]

You could try copper coloured mica powder. It does not change colour

[Terry Gallentine]

I will try a boric acid overcoat on the copper powder to see how it works. I am also trying out a couple of mica powders to see if they give me the metallic look that I am after. I have run into several sources for the mica powders (paints, cosmetics and fusing) and I was wondering if they are all basically the same thing?

[Lynn Perry]

Terry, you might want to take at look at this excellent posting:

http://www.warmglass.com/phpBB/viewtopi ... ca#p345408

[Clarkie]

When I was doing beads I found that I had to use white powder with copper in order to have it work. And it did! Good luck.