Functional Stoneware by Peggy Ahlgren
The Process
The process of making a pot involves many steps. Each piece is
probably handled 30 times from the moment it starts as a lump of clay until
the pot is sold and wrapped in a bag for you to take home.
When I took classes in Boulder, Colorado in the late
60's, I learned many of the basics never taught in a university. I
learned how to formulate a clay body, make glazes, build kilns, buy supplies, set up a customer base and price and sell pots.
Later when I moved to
Indianapolis and started a
| small shop, one of the first things I did was go to each refractory in town and buy a 100 pound bag |
25 pound bag of
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I used to make clay twice a year. Since I use about 6 tons of clay in a year, you can imagine how many 100 pound bags of materials were lifted, mixed dry with other ingredients in a cattle trough, run through a batch clay mixer in the garage, wheeled into the shop, run through another clay mixer and packed in boxes to be used for the following six months. It was one of those Wonder Woman things.
After being Wonder Woman for years, I turned the job of making clay over to the Paoli Clay Company in Paoli, Wisconsin. They deliver the clay in nice tidy 25-pound plastic bags and stack it in a corner of the shop.
Every January I make a long list of items and quantities that I think I will need for the year. Each day that I work during the winter I pick a project. One day I may attempt to make 150 soap dispensers, another day 50 garlic keepers. Being a production potter means that I repeat making similar objects. I love to throw so this works just fine for me.
Once I decide on a given item, I check my notes and see how much clay I need. A soap dispenser takes 9 centimeters of the clay extruded from the clay mixer. Each pie plate in a group of 100 may need from 1-1/2 to 6 pounds of clay. There may be 8 or 9 different weights involved in the series and the end product may result in 10 to 12 different sizes of pie plates. Pieces using the same weight of clay may vary in width or height.
The clay mixer wedges the clay
and extrudes tubes of
clay. The clay is
then cut into the right length for the
desired piece
and patted into balls
ready to be thrown.
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Each piece is created using a series of coordinated hand movements. First the clay is "centered" on the wheel head, then "opened" to create a base or floor in the pot. Next the walls are |
As the pieces start to dry they enter a stage called "leather hard." At this point some shapes are turned upside down, re-centered on the wheel and "trimmed." This process is similar to working on the lathe. Excess clay is removed to form a "foot" on the piece or smooth an uneven surface. Other pots may have handles attached to them at this stage. The pots are then signed and set aside to dry. Often thin plastic is draped over the pots to help them dry slowly and evenly.
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In the first firing, the bisque firing, the kiln will reach a temperature of about 1600 degrees Fahrenheit. Upon completion, they will be similar to a red clay flower pot in that they can still absorb moisture easily. Plates, mugs, and bowls will be sorted into groups that are about the same size, then labeled, stored and ready to be part of a future set of dishes.
In the bisque firing the pots can be stacked
and can touch. Once fired the dry grey
pots
change into a soft pink. They are still fragile
and will break
easily, but much
stronger
than in the greenware stage.
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The pots are dipped twice into large
buckets of glaze. Each time the glaze covers about 80% of the pot.
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These pots have been dipped twice into a basic coating of white glaze. They are waiting for the designs to be brushed onto each piece. |
These pots now have the designs painted on their surfaces with iron oxides. When fired they will become the "dark blue" glaze. |
The mint green pots will become the "teal" color. The wax "resist designs" will burn out to create the design. The reddish-brown pieces will become Carlton Ball's Brown-Black. |
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The next step in the
process involves "stacking" or "loading" the kiln again, but this time
for the glaze firing. All of the shelves are again removed.
Then
begins the process of building them back up. Each shelf height varies depending on what pieces are going in on that level. In the glaze firing the position of each pot is critical. Pots can't touch each other and each glaze has a different temperature range, so some pots must be placed in the hotter bottom of the kiln, others in the middle, while the light blue glaze prefers the cooler top levels. |
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Before
and After
These two photos show the pots in the kiln before the glaze firing and the
same pots after they have endured their trial by fire. The pots shrink
about 10% as the clay vitrifies and the colors change drastically with the
intense heat.
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About two days later
the kiln is cool enough to pull open the door and look at the pots. The
occasion may be accompanied by feelings of apprehension, joy or
disappointment. After looking at the pots it is time to remove them and complete the final steps. Each pot is put on a grinding wheel to remove the iron particles that have come to the surface on the bottom of each pot during the firing and make the base of the pot smooth. |
  Glazed pots on the
kiln |
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The pots are then ready to price and put
out for sale. With the drying process, it takes a minimum of 3 weeks from the beginning to the end of the process. The kiln is large and holds about 300 to 350 pieces, so an immense amount of work needs to be done to create this many pieces. |
