Thursday, January 3, 2013

Shadow and Light

In Chinese philosophy the concept of Yin-Yang, often called "yin and yang" - literally meaning "shadow and light" - is used to describe how seemingly opposite or contrary forces are interconnected and interdependent in the natural world; and how they give rise to each other as they inter-relate to one another. The concept lies at the origins of many branches of classical Chinese science and philosophy, as well as being a primary guideline of traditional Chinese medicine. Which is why a local veterinarian looking for something special to gift some lab mates, all learning the art of acupuncture for animals, asked me if it was possible to make some earrings with the yin yang symbol on them. She suggested the yin yang symbol, but I thought I might be able to find a Kanji symbol (Chinese character or calligraphy) that might work just as well - I had "balance" or "healing" in mind.  

Kanji characters are elegant on so many levels - individual characters often convey abstract meanings all by themselves and when combined can be used to communicate complex meanings. And they're all lovely to look at. However, I couldn't find what I was looking for, if I was to proceed as I had intended; so I went back to her original idea of using the yin yang symbol.

What I decided to do when she initially approached me with the commission was to make the earrings out of fine silver metal clay. There are a multitude of different metal clays out on the market now (including but not limited to copper, bronze, sterling, & gold), but what I use is the very first kind that came out called PMC (Precious Metal Clay), created by Mitsubishi in 1990. When PMC comes out of the kiln it is 99.9% silver .. not sterling (which is 92.5% silver).

Mitsubishi makes three kinds of silver clay: PMC original, PMC+ and PMC3. They each have varying degrees of microscopic silver particles, binder and water in them which affects how long you can work with them before they begin to dry out, how much they shrink in the kiln, and how strong the resulting piece is out of the kiln. PMC+ and PMC3 have less water and binder and both create a stronger end product. This makes them good for things like rings, clasps or entire bracelets, which all get a lot of abuse. I usually make earrings and pendants out of PMC original, which shrinks more, though I used PMC+ for the earrings because I didn't need a lot of shrinkage. In fact, I was hoping for very little, and PMC+ shrinks only about 10% to 12%. 

The thing that held me up the most in completing the commission was finding an appropriate image I could use to make an impression in the clay. I have a drawer full of rubber stamps of all kinds, as well as a few antique metal molds and a few molds I've made myself. Though, alas, there's not a single yin yang symbol among 'em.

Here are some of the impressions I was able to get out of the few Yin Yang stamps I found online. I returned several stamps that were unusable due to their size or design. Some websites only show the resulting stamped image and not the actual stamp .. the stamp itself must make a clear, just deep enough, impression. Not all rubber stamps work well for this process.

These impressions were all made in silver polymer clay, not metal clay, just to give you an idea of what the images look like. All of the top three, surrounding the quarter, were just too big (OK for a pendant, but too large for earrings - even with PMC original's 30% shrinkage). And - for one reason or another - I just wasn't happy with the resulting images from any of them.

The smaller stamped examples along the bottom came from a lovely little wax seal rather than a rubber stamp like the other three (a serendipitous discovery after a LOT of searching and several rubber stamp failures!!). It was the right size, the design is nice and even, and the stamp impressed well .. relatively well, anyway. I did have some issues getting the image to stamp evenly in metal clay, but was able to work most of the trouble spots out while the disks were still in their clay form.
Dried PMC earring prior to cleaning

After cutting and sufficiently drying, the little pieces must be cleaned up .. I use a small emery board to clean up areas like the little ridge along the left bottom of the dried piece shown. I then use a series of successively finer micro sand papers (beginning with 400 grit and working up to 8000 grit) to smooth out other minor issues and to create a shiny finish. I also had to use the point of a small, round file to deepen and define the two small impressed circles in each of the ten earrings (the commission was for five pair). I did that first so that successive sanding would eliminate any rough edges around the circles.

Once out of the kiln, I tossed everything (the earrings and two shelves worth of additional pieces) into the tumbler. This work hardens them just a bit and cleans off the fine silver "glitter" surface created by the kiln. I then patinated them with liver of sulfer (sometimes called antiquing). I discovered a longer lasting and more stable gel version of liver of sulfer several years ago and love it! A couple drops in a dish of warm water, then drop your clean pieces in. Unfortunately, deeply impressed segments often don't darken - no matter how long you leave them in there. When that happens, I take a very tiny brush, dip it in Black Max (another, quicker, way to antique) and just briefly touch the spots that need to be darkened. The letters in the pendant tags, the little circles in the yin yang design, even the line delineating the left side from the right, all needed a bit of help. Patinating a piece like this, especially one with a deeply impressed design, helps to make the design as a whole "pop". 

After the Black Max dries, I take a small piece of "000" steel wool and clean off the surface of the pieces. This will bring out the shine on the surface portions and leave the blackened segments so that the design shows.

Ten little earrings with wax seal and original pre-kiln size

After all that, all that's left is to add the leverback earring portions and  package them .. print off some earring cards and pop them into a box for delivery. 

All five polymer clay examples, plus the finished product!

There was a lot more frustration in impressing, cutting and finishing them than I thought there would be. I ended up having to use the large, open, round end of a cake decorating point to cut them out after I impressed them .. it was the only thing I could find that was the right size. If I didn't press evenly when I pressed the wax seal into the clay, I'd get one side thinner or fatter than the other. And there was no way to determine if I got it right, except to cut out the design. I rolled up the clay and started over more than once. And PMC+ dries out relatively quickly, so there's not a lot of time to mess around. An additional concern was the little ring at the top that allows the silver yin yang symbol to attach to an earring. I've soldered things like this onto kiln-fired pieces before, but I was concerned about doing it perfectly .. ten times. So I used a little fine silver embeddable jump ring, which is a ring with a small tab on it that inserts into the clay (it looks like a tiny little tennis racket .. the entire thing is only about 7mm long). The cut out clay pieces had to be thick enough to accept the insert, and just inserting the tab turned into yet another learning experience (and resulted in as many clay re-rolls and starting over as the impressing and cutting portions did). If I didn't insert exactly into the center of the cut disk, the tab would create a small bulge through the front or back. Not so bad out of the back, but a bulge like that ruins the look of the design on the front. You can see a slight bulge on the dried clay below, which hasn't yet been cleaned.

I was understandably thrilled once they were all completed, packaged, and ready to be delivered .. YAY!!