2/26/13

Making a (Wearable!) Color Test Strip for Enamels using the Cloisonné Technique





Some time ago I took a class in cloisonné enameling and returned quite eager to get started on my first project. So I took the plunge and ordered some fine silver cloisonné wire and a whole spectrum of yummy colors of transparent Japanese leaded enamels. I chose Japanese enamels for the brilliance and variety of colors; I chose transparent enamels as opposed to opaque enamels so that the fine silver backdrop of my piece with its wave texture would be visible through the enamel.  Opaque enamels might be better suited over copper, for example, or where the background of your enameled piece doesn’t need to be visible.

In order to determine exactly how these colors would fire over fine silver – it should be noted that fired enamels bear very little, if any, resemblance to their appearance in powder form -- I made a color test strip. Not wanting to waste a good piece of fine silver on a mere test, I decided to design a slightly more interesting piece that could be worn as a pendant. Accordingly, I first crafted a textured rectangle of fine silver with a hanging hole.



Before going any further with my description, I'd like to say a few words about safety precautions with enamels in general but with leaded enamels in particular.  Think about the effect on your lungs of inhaling powdered glass!  Every step I took during the creation of this color test strip was made while wearing an N95 3M particulate mask to avoid inhaling the enamel dust. I also mixed, washed and applied these enamels outdoors on my deck. When I was finished working, I packed up all my supplies and thoroughly washed down the table on which I was working (there's nothing quite like wetting enamel to keep the particles from becoming airborne), washed my hands, stripped off my clothes and threw them into the washing machine, and took a shower. I didn't want to allow a single grain of enamel to cling to me anywhere. Always work sensibly with enamels. Even non-lead-bearing enamels are harmful if inhaled.

Once I had the pendant fired, burnished and tumbled, I brushed the front of the pendant with enamel adhesive and then used a sifter to uniformly apply a layer of clear flux (enamel) over the entire piece. When it was dry, I fired the pendant at 1500 degrees Fahrenheit for exactly two minutes in a pre-heated kiln and then quickly removed it to cool. Then I did exactly the same thing to the reverse side of the piece to counter-enamel it. The clear flux acts as a barrier between the fine silver and the colored enamel to enable the colors to remain true. Sometimes enamel colors, when applied directly to fine silver, have a tendency to change. This is especially true with pinks and reds which will sometimes turn orange when applied to fine silver.

I then applied my cloisonné wire to the pendant, adhering it by dipping it first into enamel adhesive. I took care to ensure that I cut the edges of the wire at precise right angles so all parts of the edges would come in contact with the adjoining pieces; you don't want to leave any gaps which might allow the enamel to flow out of its cell or worse, show when you're grinding down your finished piece and suddenly a gap appears. Once dry, I fired the pendant again. Because the flux re-melts during firing, the cloisonne wire actually sinks into the flux and is permanently captured as the piece cools off. Here's how the pendant looked after the cloisonné wire was fired in place:




You can see that the ends of the cloisonné wire extend over the edges of the pendant; this is done deliberately to avoid cutting the ends too short. It's safe to trim this excess wire after the first few coats of enamel have been applied and fired.

Before proceeding, I drew a rough diagram showing the placement of my wire and wrote the code numbers of the enamel colors I planned to use into the cells so I could keep track of which colors I wanted to place where and also have the ability to remember which colors I used on the test strip for future reference.


Since I had already washed the enamels and placed them into coded jars, I was ready to roll. I spooned out small amounts of the colors I had selected and placed them in numerical sequence into a plastic paint tray, adding a few drops of distilled water to each color to prepare them for wet-packing into the cells.


Then the fun began as I carefully filled the cells with their assigned colors. It's not necessary to put down the entire first layer; so I applied just the first few and fired them in place. Again, 1500 degrees F for two minutes. I used a tripod because now, with the reverse side of the pendant counter-enameled, the piece needed to be suspended so that the back wouldn't melt against the firing surface (a square of mica placed on my kiln furniture to protect it from the melting enamel). All subsequent firings after the counter-enameling were done on a tripod.


The applied but unfired enamel almost has the appearance of powdered sugar when it's dry enough to fire.

I continued to apply the enamel to each cell and fired the pendant. I also again counter-enameled the back, this time adding a solid color to the entire reverse side before firing again.

Here, you can see the first full layer of color after firing. It's necessary to continue applying and firing layers of enamel until they reach or slightly exceed the height of the cloisonne wire -- any excess can be ground down later, but ultimately the piece should feel smooth and level to the touch once the piece is finished.
 



Repeated firings were done as more and more layers of color were built up on the piece.

Here's another photo showing how I achieved shading of colors in some of the cells -- I applied enamel selectively. These areas turned darker when they were fired.



 
After the final layer of enamel had been fired, I finished the test strip by burnishing the surface under running water with an alundum stone and polishing it with successively finer grits (120, 200, 400 and 800) of diamond pad grinding sticks. I carefully removed any remaining glass powder residue with a glass brush and finally fired the pendant one more time to fire-polish it and return it to a nice shiny gloss finish.

Once finished, I mounted the pendant on a silver chain and now wear this piece whenever I'm working with my Japanese enamels as a reminder of how each color looks once fired.  And instead of having a pile of random wasted color test pieces, I have a lovely cloisonné enamel pendant I can wear any time!

written by Beverly Miller Gallerani of Mango Tango Designs

2 comments:

kim said...

great post beverly, nice to have such detail when you are teaching about enameling!

Anthonia Onwordi said...

Beautiful pendant and a great idea for testing on silver.

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