What's In A Mug - Making a Stoneware Mug
Updated: Mar 23, 2020
Like every piece of handmade pottery, there are a lot of steps from a lump of clay to a finished piece. Perhaps contrary to expectation, making the form itself is the least of it… Keep reading to learn more about what goes into your mug, besides coffee!
These mugs are thrown on a potters' wheel then slowly dried over a few days, as drying too fast can cause the mug to crack. These dried pieces are called greenware. Once enough greenware is made to fill my kiln (which is quite a lot), the pieces are fired for the first time.
This first firing is called a bisque firing and the purpose of this is to heat the pieces to a high enough temperature that a chemical change in the clay takes place and virtually all the moisture is evaporated. This firing usually takes about 12-14 hours, depending on the kiln load. The piece becomes much harder and is now ready to glaze and decorate.
The bottom of each piece is coated with wax to stop glaze from sticking to it – otherwise, every piece would stick to the kiln shelf when fired the second time. I use additional wax to expose more of the clay body for a more earthy feel.
The pieces are then dipped in different glazes or combinations of glaze, dried over 24-48 hours then loaded back into the kiln for the second and last firing called the glaze firing. The kiln temperature in this firing is much higher and brings the clay to its final, matured state. This is where the final “look” is produced and depends on several variables, not just temperature. A glaze firing can take anywhere from 12-16 hours, depending on those variables.
This is just a quick overview of the process – there are many more small steps in between and the thoroughness and time taken for each step determines whether opening the kiln after a glaze firing is like tearing open the best present ever or… not.
I’m always happy to answer questions or talk about something special you’d like made. Email me at whittalc@telus.net anytime or check out the latest at Studio 83 Clay Works on Facebook and Instagram.