My peripatetic practice leads me down many wandering roads, but it keeps ringing true for my practice, both as a potter and teacher. I decided long ago to embrace my meandering mind instead of beating myself up about staying on task. This became clear when a parent said to me, "I want that for my child," when she enrolled her daughter in one of my first art classes in 2012. She said, "I want my child to learn how to feel their way through this world." That really stuck with me. As I am forever the student eager to learn more as I endeavour to teach what I know.
You can learn so much from social media these days. Instagram is great for inspiration! YouTube will teach you how to do almost anything. But the problem with the internet is that beginners can be inspired to jump right into advanced techniques without fully understanding the process. Which is why studying ceramics with a qualified instructor is a very good idea.
So, like Aristotle, (yes, I am so full of myself that I compare my teaching practice with that of the great philosopher) I want to take you on a meandering thought process. The theory is that the journey is as enjoyable as the knowledge gained.
Some of you know me from when I was teaching ceramics at the Art Centre and Theatre (ACT) in Maple Ridge. There we fired the electric kilns to cone 6. Some of you know me from when I was the technician at Port Moody Art Centre, where we also fired our electric kilns to cone 6. Most recently I have been teaching ceramic arts at Bonsor where we fire our Skutt to cone 05. Now I am with the potters guild at the Shadbolt Centre for the Arts in Burnaby where we are firing a gas kiln to cone 10. If you don’t know what the difference is between these firing methods then you are in the right place. Not that I will go into the technical differences, (there are lots of YouTube videos for that) but I mean that you are a beginner. Most of my students are beginners. This blog is primarily for them.
Recently, I have had students in Burnaby a little confused about the difference between pottery at Bonsor vs. pottery at Shadbolt. To this I would say it is a completely different approach to ceramics. However, the most important thing to be aware of, is that we fire our kilns to a different cone.
To the point
Most pottery classes use electric kilns. Most electric kilns are made by the manufacturing company named Skutt.
A “cone” is the ceramic measurement for a firing. It is temperature combined with length of time to reach a particular melting point.
IT IS VERY IMPORTANT THAT YOUR CLAY AND YOUR GLAZES MEET THE SAME MELTING POINT.
Cone 10 is high fire. You can easily look up the technical differences by smarter potters than I. For our purposes, This is a great choice for durability. Usually potters making bakeware will fire their work to cone 10.
Cone 5/6 is most common. It is a good mid range for functional ware and sculpture. It is quite durable. Most potters do their dish ware at cone 6.
Cone 05/06 is low fire. This is best for decorative work. But you typically get brighter colours.
That being said, many potters that I have worked with embrace the philosophy that rules are made to be broken.
I have found that, as you can do beautiful decorative work at cone 10, you can make perfectly functional work at cone 05.
The pros and cons of each cone.
Low fire is a little cheaper to run the kiln. It does not require as much electricity to reach the desired temperature. Bright colourants often burn out at higher temperatures. So you can usually get brighter colours at low fires. However, it does still reach about 1900 degrees. So this makes it food safe, (depending on what you put on the surface) dishwasher, oven and microwave safe. However it is not ideal. Some problems you may have to address are things like chipping, crazing and retaining heat.
Medium fire is the best of both worlds.
High fire costs more to run your electric kiln because it takes more power for longer periods of time. This temperature clay is preferred for more severe firings like Raku, pit, wood and gas firing so it can take the thermal shock.