How is metal clay different than sheet metal? Since the people who buy my jewelry (probably) don’t care much, I’ve never really given much of a written explanation. However, metal clay is such a unique material, and so much fun to work with, that I’ve finally decided to document some key differences between metal clay and sheet metal, which is one of the more common materials used in handmade jewelry.
Probably the most obvious difference is that you can “make” metal clay pieces at home (with the right equipment), while sheet metal is a supply you buy ready-made. I guess that isn’t really much of a distinction, since we all have to buy our metal or metal clay from somewhere. I sell the metal clay powders that I mix myself at Cinter Metal Clay on Etsy.
What I mean is that with sheet metal, you start with an object and apply various tools (saws, hammers, etc.) to reshape it. With metal clay, you start with a blob and shape, reshape and manipulate it quite easily in its wet state. Somehow it feels like sheet metal is a form you whittle down into something, while clay is something you build up from nothing.
Sheet metal is sold in certain gauges, or thicknesses. The bigger the number, the higher the gauge and the thicker the metal is (ie. 16 gauge is thicker than 24 gauge). Hammers, rolling mills, and other mechanical processes can change the thickness of sheet metal. Metal workers anneal (heat) metal to make it easier to transform, but the more you work it, the harder it gets. If a piece gets too brittle from overworking, it can break. In handmade jewelry, 18-24 gauge are the most common for stamped metal jewelry pieces.
Metal clay is rolled out, while wet, to the desired thickness. Regular old playing cards were the tool of choice when metal clay first debuted, so often instructions will specify rolling the clay to a specified number of cards, ie. 7 cards thick. So, here a larger number means a thicker piece. 10 cards stack up higher than 7, for example. I’d estimate my typical metal clay pieces are about 5 times as thick as sheet metal jewelry, but they are lightweight due to metal clay’s unique properties (more on that below).
Sheet metal can be textured beautifully with any number of methods, so long as there is enough force (and/or the metal is annealed enough).
Metal clay is much easier to texture, as you probably guessed. Rubber stamps, cookie cutters, leaves – pretty much any interesting texture can be transferred to metal clay. For some mediums, it is better to make a mold of the texture, and then shape or texture the clay with that mold.
My favorite thing about metal clay is the texture – not really even the textures created with stamps or other surfaces. I love the texture of the clay itself. I like my clay to be a little dry around the edges when I’m working with it. That creates all kinds of little organic cracks and crevices that are impossible to create with sheet metal.
Many people do amazing things with metal clay – so amazing, you can’t tell that they used clay. I am not one of them. I love the clay because it looks like clay, and it is metal. That combination just makes me happy! I don’t really try to make pieces that look like they could have been fabricated from sheet metal. I use sheet metal when I want that look.
So, how is metal clay different than sheet metal?
Metal clay pieces are fragile until fired in a kiln. The heat sinters the metal together. This means the little particles of metal in the clay get hot enough around the edges to melt just slightly and stick together. This is why metal clay pieces shrink in the kiln – the spaces between the metal particles get smaller.
If the heat is too high, the piece can melt and all you’ll have is a blob. If the heat is too low, the metal won’t sinter enough, and it will crumble.
Sintering takes a little practice. You have to get to know your kiln and your materials. My firing instructions walk you through the basics, but expect to do a little fine tuning for your environment. But, once you’ve done that, metal clay opens up a whole world of quiet (no hammers!) easy and satisfying metal creation opportunities.