Thursday, October 6, 2011

William Carey 250th Art Exhibit Piece - Breath of Heaven - PMC

This evening was the opening reception for the William Carey 250th Art Exhibit. I had intended to make more than one piece but I just did not have the time. I did finish a silver piece that represents a flower called “Breath of Heaven” that was discovered by William Carey. This was finished a few weeks ago for the exhibit, and since this was something of an experiment for me, I decided to write about this project.

For those of you who are interested in precious metal clay (PMC) you can create fine silver objects with it but there are some problems with this material compared to sterling silver. Fine silver is .999 pure silver which is a beautiful white metal but it is softer than sterling silver which is an alloy. Precious metal clay suspends pure silver in a ceramic binder so you can mold it like clay and then the binder is burned off in a kiln. The tradeoff is that undercuts are not easy to make since the clay may slump as it is fired and bails may be too soft to support the weight of a heavier piece. PMC also shrinks when fired but sterling does not. Sterling also is easier to damage when exposed to high temperatures but it can be cold hardened. It would be great to use both together but I was not sure if this would work.

I wanted to make a larger piece with a good deal of undercuts. I decided to use sterling wire to create the bails and supports for some of the pieces. I hoped that the PMC would not shrink so much that design would distort on the sterling frame.

The real flower is a good bit smaller than this; after playing with several designs, I thought an enlarged version would be a more successful design than a cluster of the small flowers since very tiny details might be too busy in a reflective metal. I knew I wanted to use the leaves in the design.

The individual leaves and petals were created separately and then joined to a base. Sterling silver wire was used to support the stamens and the long leaves and precious metal clay (PMC) was used to build the shapes. After all the parts had dried, they were joined with more PMC. I then used very fine metal files to add details and veining and sanded the surfaces lightly with very fine sandpaper. Finally, I used PMC slip to make sure that the supports were solid and then the piece was fired.

Although you cannot really tell in the photos, the flower is a near mirror finish while the outsides of the leaves on the front of the piece have a brushed finish. The piece was tumbled after firing and then a very small fine metal file was used to give a deep directional brush effect on the leaves. The piece was then tumbled a second time for about ten minutes to add a slight sheen to the brushed surfaces. Final finishing was completed with jeweler’s papers and a polishing cloth.

I am considering using this as a prototype since the back of the piece is not completely flat. I was too uncertain to hollow the back since the unfired piece was very fragile and I did not want to damage the supports. I might use this one to create a mold and then I could create a lighter piece if the details are still intact. This one contains a full ounce of fine silver and some minimal sterling.

Overall, I really like the final product. Right now, it is hung from four sterling chains with a lobster clasp. I may come up with something better after the show is over.  On my to do list: I need to come up with a  set hallmark design and I need to learn how to photograph my work (but these aren't bad for an IPhone).

Breath of Heaven detail view


View of the entire necklace, Breath of Heaven
 The ugly back of the piece - looks like a crab doesn't it?

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