I grew up in Western Pennsylvania (coal country), and I can remember an orange-tinged stream close to my grandmother’s house. The cause was Acid Mine Drainage, which contaminates waterways near coal mines with iron, creating biological dead zones. So I was particularly interested in an article in the February 2014 issue of Ceramics Monthly. In this article, which I am excerpting from today, Skip Sensbach explains how one organization is turning this environmental hazard into a usable resource while cleaning up waterways.- Jennifer Harnetty, editor.
I have been using commercial glazes lately, because I have been working out of my home studio since I bought myself a kiln last year. This has been working okay so far, and some of these commercial glazes will remain in my repertoire, but I really want to start making my own so I can tweak them to be exactly what I want. But starting from scratch and figuring out what you need in your pantry can be pretty daunting. Not anymore thanks to Deanna Ranlett’s article in the November/December 2013 issue of Pottery Making Illustrated. Today, I am sharing an excerpt from that article, along with a pretty handy materials chart showing how commonly certain glaze materials are used at various firing temperatures. – Jennifer Harnetty, editor.
Today, Robin Hopper explains how you can achieve many different types of surface decorations and patterns in a short period of time using only a simple slip trailer. Plus he shares a basic engobe recipe.
Ahhh plasticity! It’s the property of clay that got us hooked on clay in the first place. Caused by just the right mixture of water and particle size, plasticity is what transforms dry cracky clay (like in the image to the left) into a workable material. Plasticity separates clay from dirt. In today’s post, an excerpt from the second edition of Understanding Ceramic Raw Materials: Ceramic Glaze Materials and Clay Making Ingredients (the second, expanded edition of which is available as a free download now!), we learn all about this magical characteristic.
There are probably as many kinds of clay as there are riverbanks, creekbeds, roadcuts, abandoned coal mines and backyard gullies, but most of the clays that many of us use on a regular basis are commercially mined.
There is growing recognition of the need to align our studio practice with an awareness of environmental sustainability. Individuals and groups are already engaging with green issues in studio ceramics and are devising, enacting, and posting solutions. The National Council on Education for the Ceramic Arts (NCECA) Green Task Force has been working for the past two years towards oversight of practical stewardship at the annual conference and to assist in the overall exchange of ideas and information that minimize the global impact of our field.
Ceramics Monthly and the National Council on Education for the Ceramic Arts’ Green Task Force present the winner of the NCECA Green Task Force Student Writing Competition. Student members of NCECA were invited to submit entries focused on sustainable practice in the ceramic arts. Brian Kluge, a graduate student at the University of Nevada, Lincoln, received a cash prize for his entry, as well as publication of his winning entry here. Thanks to all the students who entered, and thanks to the NCECA Green Task Force for providing Brian a few bucks to buy some (local) studio supplies.
Feldspars are minerals of varying composition commonly used by potters. Feldspars form a glassy, white surface when fired high enough. They have a very long range, they begin melting at cone 4 and continue fusing beyond cone 10. They also tend to stiffen a glaze due to their high alumina content. In ceramics there are two basic categories of feldspars: potash feldspars, in which the primary melting oxide is potassium, and soda feldspars in which the primary melter oxide is sodium. Soda and potash have the highest thermal expansion and contraction rate of all the ceramic melter oxides, they promote color brilliance and luster at most firing temperatures, and they encourage specific color results.
Feldspars are important ingredients in clay bodies and glazes. In both applications, their primary function is to supply ﬂuxes to the formulations, but they also provide additional alumina (Al2O3) and silica (SiO2). Feldspars are naturally occurring minerals and are generally classiﬁed as either potash (potassium) or soda (sodium) feldspars based upon the predominant alkali metal element (the ﬂux) that is present. The minerals commonly referred to as lithium feldspars are not true feldspars, but they are aluminosilicates like feldspars and contain the ﬂuxing element lithium, and are used for the same purposes as the feldspars.
Rosette Gault, an expert on paper clay, explains some basics of paper clay preparation and takes you through the process with some step-by-step photographs. Plus she gives some health and safety tips for working with paper clay.