Convergent Series

learning, using & teaching metal clay, and other aspects of life

Pushing, in more ways than one….

Posted by C Scheftic on 2012/07/18

About a month ago, I wrote a post about some pieces I am calling “Push Pendants” because they are made by pushing some metal clay through a piece of metal mesh. Given that I like making reversible pieces, furthermore, if you read my last post you would have seen a photo of the “other side” of yet another one of these pushed-pieces. The first photo with this post shows its pushed-side, all polished up to a nice shine. (You should be able to tell from the shape which (un-polished) “other” side it matches there….)

They’re fun to make, and I admit the original idea was not mine. They are adapted from a slightly different project I noticed a while ago in Mary Hettmansperger’s delightful book, Mixed Metal Jewelry Workshop. The approach used by “Mary Hetts” is really simple: you make the combo, fire it, then frame it in sheet metal. (Check out her book for all sorts of other useful details!) That strategy minimized one major potential issue: as the clay is fired–both burning off binder and sintering the powder into a solid metal–it shrinks. The wire mesh does not shrink. Warping and cracking can occur in the parts that began as clay! Her process minimizes that as a problem by having you frame the sintered metal with some other solid product (e.g., sheet metal, but you could use wood or fiber or plastic or whatever else you want). First of all, you don’t get very much cracking that way; secondly, you can probably just cover up any you do get.

But I started to wonder: what if you just framed it with more clay from the start? How much of a problem could that be? What are the variables involved? How much more difficult would that make the whole task? Would it still be a good project for a workshop that included both experienced and novice metal clay artisans?

After several months of experimenting (and confirming a few of my suspicions with Hadar Jacobson at the recent PMC Guild conference), it is looking to me as though:

  • With these, it helps if you are someone who is willing to accept what the kiln gives you: they’re not totally unpredictable, but even tiny variations in construction can have very noticeable effects!
  • Giving the piece a bit of curvature, a hint of the direction in which you want it to warp, can be helpful.
  • Really thin surfaces, front or back, do tend to crack.
  • Thicker surfaces have a more complex relationship to the warping and cracking, but there are ways to minimize such problems (and to make it easier on yourself to patch cracks and refire if you find that desirable).
  • The position of the mesh in relation to the frame matters as to whether and how much the piece will crack along the side.
  • The variance in shrinkage rates across the different clays makes a difference in the patterns of shrinkage and warping in these pieces. The pattern of least to worst is predictable; the exact extent seems not to be.

I’ve had people ask me why I bother with these clays if I have such problems with them. Well, the answer is that both the explorations and the results are, overall, delightful. Most of the time, pieces do turn out fine. And some of the so-called problems that do occur are ones I’d never have with silver because it’s just much simpler and more reliable to fire. But I realize that others happen because I try things with these metals that I would never think to try with silver or, if I did think of them, would be unlikely to try because of the price of silver.

In this example, besides simply pushing clay through mesh, I feel like I am pushing the envelope; that is, I feel like I am also extending the current limits of the clay’s performance, going beyond some commonly-perceived boundaries of working with it. I find the process of exploration to be fun, itself, in addition to any reactions I have to the resulting pieces or the subsequent workshops I may teach from what I’ve learned.

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