The Process of Making Mugs

Let me tell you a bit about the process of making mugs for a special order.

Background: The person wanted the names of her grandchildren on a mug for each child. Being left handed myself, I'm a little OCD about wanting to see the name or image when I hold my coffee mug. So when this wonderful lady asked for names on her new cups, I discovered that nearly half of the mugs would be left handed, and some would be in red glaze, while others would be in green glaze. It turned out that I needed a spreadsheet to keep the order on track.

Here’s how I made those mugs.

First I threw/turned the mugs on the wheel, and let them stiffen up for a few days under plastic. They have to be the right stiffness in order for me to hold the mugs without deforming them.
Pulling Handles

Then I pulled the handles from lumps of clay and attached them to the mugs, right handed and left handed.

I also added the extra embellishments, and marked out an area for the names.

In that area for the names I painted the raw clay with some white slip. Slip is like watered down clay, with coloring.
Then I let the mugs set up a bit to allow the moisture to equalize throughout the mug.


The next day, I painted on more white slip, to strengthen the white color.

Then I painted on the names with underglaze. It took a couple of coats to hopefully make the colors strong enough to stand out.


Next, I let the mugs sit under plastic again for a few more days to let the moisture equalize, then I take off the plastic and let the mugs dry thoroughly. The drying can take a week or it can take several weeks, depending on the weather.

Then I bisque fired them in the kiln. That means they cook to a temperature of 1945 degrees Fahrenheit.
They cook for about 9 hours, and then cool down. In about 24 hours, I can open the kiln safely. When the mugs are bisqued, they come out of the kiln with a density similar to bones.

Next, I glazed the mugs.

First I painted the name area with a clear glaze, although it doesn't appear clear until it is fired.

Then I painted the name area with a liquid wax. That was done because glaze does not stick on waxed areas. This meant that I could glaze the entire mug with the colored glaze, and dab off the colored glaze from the name area..

a finished mugUsually I use my own recipes for making glazes, and make 5 gallon buckets of the stuff at a time. The mugs were then dipped into to the bucket of glaze.

Then I dipped the mug rims into the bucket of beige glaze. And put the mugs back into the kiln.

The mugs stay in the kiln at least 24 hours. It takes about 10 - 11 hours to fire to 2235º F . This temperature vitrifies (makes glass like) the clay I use, making it safe for microwave and dishwasher use. (Different clay bodies have to be fired to different temperatures.)

Then it has to cool down slowly. If cooled too quickly, the mugs could break.

It takes about another 13 - 15 hours to get the temperature down to where I can safely remove the mugs from the kiln.

And that's the process of making mugs :)