I have been using this very dark colored claybody for most all of my work. I have been firing at cone 10, but only at a glaze reduction, not body reduction, and getting great results--though not always constant. Anyhow, I have always loved the deep chocolate color I get, but when I fire it with a body reduction it bloats.
This is the recipe that I have been using:
Red-Brown Stoneware Throwing Body Cone 10 Shrinkage 9.8%, plasticity 11, glaze rating 11.1
Jordan clay* 30.0 Redart clay 27.0 Kentucky ball clay #4 18.0 Feldspar (Buckingham) 5.0 Silica Sand 15.0 Fire clay (calcined)* 5.0
I have been substituting *Fire clay (calcined) with AP Green and *Jordan clay with Goldart.
I believe that the AP Green is fine, but is the Goldart the wrong choice for a cone 10 body reduction firing? What can I use instead? Cedar Heights fire clay? EPK?
Maybe the Goldart isn't the problem after all? This recipe has an awful lot of Redart in it, could this cause the bloating? What do you think about adding manganese to a cone 10 claybody for color? Is this something I should avoid if possible (due to health reasons)? What alternatives do I have?
What I need is a DARK claybody (I don't always use glazes) that can withstand a cone 10 body reduction. Can you help me change this recipe so that I can get my desired results? Maybe you have a recipe that I might be able to try. *NOTE: I want to throw and sculpt with this body.
Thanks in advance for any help that you may have to offer,
Muuurgh