Electric kiln firing is one of the most common firing methods because electric pottery kilns are readily available and simple to install, but that doesn’t mean that they yield common results. Electric kilns can be incredible tools in the pottery studio. In this collection of articles, you will see how creative potters and ceramic artists are using electric kilns to create exquisite ceramic art.
Not only can electric kilns produce great results, but they also offer control and dependability. And electric kilns keep be- coming more versatile, economical and easy to use with advances in controllers, energy efficiency, materials, and safety. Here, you’ll learn ways to improve your electric firing results and be ready to take advantage of the incredible potential offered by electric kiln firing.
Here is an excerpt from Techniques and Tips for Electric Kilns: Inspiration, Instruction and Glaze Recipes for Electric Kiln Firing:
Electric Kiln Firing Success
by Jonathan Kaplan
Color and texture in cone 6 glazes are the result of three variables: First, selecting proper glazes; second, learning how to layer and combine different glazes by pouring, dipping and spraying; and third, using a controlled cooling cycle to further enhance the color and texture. This slow cooling not only creates a visual dialog in thick and thin areas of glaze application, but also helps with the crystallization of certain materials, which adds depth and interest to the glaze.
I spray or dip glazes over each other. My experience is that no single glaze can provide a visually interesting surface in an electric kiln, although there may certainly be exceptions. My layering technique allows the many differing glaze materials to combine and melt in unique ways, providing a visually interesting surface with depth. All of this is caused by the interactions of multiple materials applied over each other. Applying glazes over textures in the clay allows the melted glaze to pool. A thicker concentration of glaze materials in these areas yields different areas of color.
When mixing and testing glazes for future use on your pottery, it is useful to try different methods of combining glazes. For example, if you mix up a few small test batches of different glazes, try dipping one glaze over the other on the top rim of your test tile. Then reverse the order. For instance, if you dip glaze A over glaze B, then do another tile with glaze B dipped over glaze A.
Most glazes have a range of several pyrometric cones. I fire my cone 6 glazes to cone 7 using a programmable controller with the following heating and cooling cycle:
1st segment – 50°F/hour to 220°F
2nd segment – 250°F/hour to 2167°F
3rd segment – 150°F/hour to 1500°F
I have found that this provides a better melt and allows a good mingling of the many layers of glaze. It’s necessary to experiment and test your glazes to determine their range. Kiln wash or stilts under your ware is a necessity!
It is fine to program a “hold” into the end of the second segment if you have a single zone kiln and wish to try to even out the firing from top to bottom. With the introduction of multiple zone controls on many of the new kilns, a soak at the end is not really necessary. If you don’t have a computer-controlled kiln, use the infinite switches to “fire down” the kiln. With the addition of a pyrometer and a decent thermocouple, you can achieve a reasonable controlled cooling cycle.
It’s important to keep accurate records so when you get results that are pleasing, you can repeat them. In an electric kiln, repeatable results are easier to achieve than in a fuel-burning kiln, especially if your electric kiln is equipped with a programmable controller. There is no substitute for experimenting. It takes time and persistence to achieve the surfaces that are pleasing to you. No one glaze or method will work. It is a combination of glazes and applications, followed by the proper firing with a controlled cooling cycle.
Remember to always test new glazes before committing them to your finished work!
Techniques and Tips for Electric Kilns: Inspiration, Instruction and Glaze Recipes for Electric Kiln Firing also includes the following:
With an initial impetus in the energy crisis of the 1970s, Schatz began exploring options for translating her high-fire reduction glazes into cone 6 oxidation glazes for electric kiln firing. While the exact results were not possible, she learned a lot about glazes, and passes those recipes on to you.
Electric Kiln Firing Success
by Jonathan Kaplan
Jonathan Kaplan explains how layering and combining cone 6 glazes and using a controlled cooling cycle can create some exciting surfaces in a electric firing.
Potter Harry Spring shares his cone 6 wood-ash glaze recipes and explains how has come to appreciate the convenience of electronically controlled kilns.
Ten Basics of Firing Electric Kilns
From the Pottery Making Illustrated Instructor’s File Archives
source from http://ceramicartsdaily.org