Clueless in Ceramics

University of Oregon Craft Center instructor Renae Kowitz hunched over the potter’s wheel and set her hands on a two-pound ball of clay.

It takes a little scientific knowledge and numerous artistic steps to get from raw clay to a finished ceramic piece.

Kowitz shapes the bowl

Kowitz has been doing ceramics for more than 17 years and has worked at the craft center since 2004. She has created everything from a functional set of bowls to abstract artistic pieces.

Kowitz carefully measured two hunks of clay and wedged it on the table to get rid of problematic air bubbles. Air bubbles, she said, can cause a piece to explode in the kiln when the air in a piece is exposed to high temperatures.

She then grabbed a round wooden plate, called a bat, and secured it on the metal surface of the wheel. The bat keeps the clay stationary and protects her hands from chafing on the spinning metal wheel.

Kowitz put on her favorite clay-splattered apron, flipped a switch on the side of the wheel, set the pedal at a medium speed, and began working with the clay.

She kept her hands completely steady as the wheel started turning as she let the clay conform to the round shape of her hands.

“You are trying to get the clay into a really symmetrical shape on the wheel so that all sides are even and centered on the bat,” Kowitz said.

Watering the bowl with a sponge

It often takes hours to center the clay, she said. Many problems can arise throughout the throwing and firing processes. Sometimes a bat won’t stick to the wheel, a piece of clay won’t center because it has air bubbles, or the ceramics crack during firing in the kiln. It took less than five minutes for Kowitz to make two perfectly symmetrical bowls.

“I don’t assume everything I center is going to end up a finished piece,” she said. “Accepting imperfection is key.”

Kowitz determined if the clay was centered by looking at how it stayed in the center of the bat instead of wobbling around. Then she stuck a finger directly in the middle of the clay and pushed against the side to open up the piece. How much she opens the clay will decide whether or not she makes a cup, bowl or plate. Occasionally she took the sponge from a nearby water bucket and watered the clay to keep it malleable.

“The most advanced form to throw is a teapot or anything with a lid because you have to make a spout and handle before the clay dries, which requires more devotion to a single piece,” she said.

Kowitz stopped the wheel and slid the wire tool under the bowl. She used the wire to separate the clay piece from the wooden bat to move it to a wooden slab. Kowitz covered the clay bowl with plastic and let it slowly dry out for a few days to avoid cracks.

Kowitz loaded the bowl into the first kiln to be bisque fired, which removed all residual moisture from the piece before glazing. Then Kowitz dipped the bowl into her glaze of choice for the final firing where the glaze reacts with the high temperatures and creates different colors.

A few days later Kowitz unloaded the shiny new ceramics from the still-warm kiln, which held numerous bowls, mugs, vases, and plates. After moving the finished pieces into the studio, she set the vibrantly colored ceramics on designated shelves surrounded by walls of dusty unfinished work.