In this post, I decided to cover three topics in one project: (1) Using molds intended for polymer clay with metal clay (2) decorating the back of a pendant and (3) patinaing Five Star bronze.
Polymer clay molds tend to be larger than metal clay molds. That makes them impractical for many purposes. However, there are two steps you can take to make polymer clay molds more artist friendly. The first is to use copper or bronze clay. Copper and bronze are much less costly than silver. This brings down the project’s cost. Secondly, there is the issue of weight. This can be addressed by making your project partially hollow.
I say ‘partially’ because a completely hollow piece of metal clay often needs internal support while firing. That is another topic, to be discussed later. However, small hollow spaces within a pendant or earrings can save considerable weight and generally do not need support.
For this project, I chose Penni Jo’s mold of a sea turtle (http://www.bluewhalearts.com/best-flexiable-mold-by-penni-jo-sea-turble-bezels-cabs.html).
I chose the smaller turtle. Even with some hollowing out, the larger turtle might be too heavy to wear (although it would make a really nice paper weight!).
The first step is molding the body. Because the head is undercut, it is necessary to work the clay into the mold using one’s fingers. It might take several tries to get it right. The shell is molded separately. However, by forcing a laying of clay 1 mm thick into the shell mold, and then trimming the excess, one can produce a very light shell. The shell can be decorated as one wishes (more on that later).
I used Five Star bronze clay. Five Star bronze clay has a really nice property — if you place two wet pieces of clay together and let them dry, they tend to bond. I placed the shell in the turtle’s back, with the intention of making sure they dried to the same shape (clay can distort slightly in the drying process, so two pieces that fit perfectly as wet clay might not fit as greenware). However, by the time the pieces dried, they had bonded as tightly as they would have if I had joined them with slip.
Because the shell was so thin, I did not want to put much pressure on it. One option would have been to decorate it after it dried. However, I chose another route. While it was still wet, I punched many small holes in the shell, using the needle tool. That gave it the look of an almond shell, and I liked that look.
The unfinished greenware looked like this:
When pendants are offered for sale, customers often turn them over and look at the back. One way to deal with this is to decorate the back. I chose to texture a thin (0.5 mm) sheet of clay, cut it in the approximate shape of the turtle, and, after it dried attach it. There are a number of ‘bobbles’ in the wet clay (the pieces are not precisely the same shape, there are some gaps in the clay). All of these are fixable in the greenware stage.
I attached the back and sanded the greenware. I attached an embeddable bail. I had originally planned on attaching it to the tail, but was not able to get a solid bond — presumably because the tail gave less material to bond to. Five Star bronze requires two stage firing, one short firing open shelf and a longer hotter firing in charcoal. Before the greenware went into the kiln, it looked like this:
This is what it looked like after being fired and given a long ride in the tumbler.
I decided to patina the piece. Since there were so many small curves, I decided to use liver of sulfur — a dip will allow the patina to enter all the small crevices. This is where I learned that Five Star bronze does not take liver of sulfur particularly well. The piece only slightly darkened. However, it acquired a faint purple tinge that, unfortunately, did not show up in the photo. You’ll have to imagine it ;-). I decided that I liked the purple tinge and did not change the patina. The coin in the photo below is for scale.
Finally, the back of the piece looks like this. I deliberately gave it a primitive look in the greenware finishing — the more I worked with the texture, the more it looked like a Polynesian petroglyph, and I thought that was an appropriate motif for a sea turtle.
So there you have it. I will continue to explore Five Star clays and how they can be used. I hope you will too.