Hsin-Chuen Lin

Learning the Fundamental Concepts of Centering Skill

Love it or hate it, every potter needs to come to peace with centering. Once again, Hsin-Chuen Lin patiently walks us through this essential foundation of wheel work.

Lin suggests that beginning potters use a piece of wedged clay between two and three pounds. This makes for much more manageable centering. He also recommends that students don’t choose an overly hard or overly soft clay, as these conditions add difficulty.

Typically, pottery wheels are scored with circles, which makes it easy to visually discern where “center” is.  He places a ball of clay in the center, pats it down to be sure it’s sticking to the bat or wheel-head, and then begins to spin the wheel.

If you’re a beginning student, Lin has a great tool for remembering the basics of centering. He calls it “The Three Ss.”

• Speed: When centering, the wheel should be spinning rather quickly, at about 80% of capacity. The potter’s hands should move up and down the clay rather quickly as well.
• Slippery: Keep the clay wet with water or slip. Dry clay means friction between hand and clay, which can pull the clay off center.
• Strong Support: Create strong support by resting your right hand against your hipbone and on the splash pan, and using palms, not fingers to shape the clay as it centers.

Using palm pressure, lightly squeeze the clay up into a cone, and then lightly push it back down. In this squeezing and pushing process, the left hand moves the clay down while the right hand creates a “wall,” keeping the clay in the centered space.

How can you tell if your clay is centered? Resting your right arm on the splash pan and resting your right hand on the spinning clay, feel whether the spinning mound is vibrating and bumping, or whether feels still and smooth as it spins by. If it is still and smooth – the clay is centered!

Lin does a little bit of trouble shooting at the end of the video. Having been a ceramics teacher for years, he knows what common problems beginning ceramics students face!

Common errors:

• Flattening the top of the clay as you pull up. Beginning potters may try to pull up a cylinder rather than a cone. The flattened top of the cylinder will likely become concave as the clay is squeezed and pulled upward, leaving a “volcano” like lump of clay on the wheel.
• Using clay that is too hard – this can make centering impossible for beginners
• Using clay that is too soft – this can also make centering a challenge for beginners
• Moving hands too quickly when pulling off from the clay – a quick motion on the delicate point of the clay one can pull the clay out of center.

We know that this will make a lot more sense when you’re sitting at the wheel, but watch the video and try to keep some of Lin’s principles in mind next time you’re throwing!

Tim See

Help! I Can’t Center!

Learning to center clay can feel like a daunting task, but in this video, Tim See walks us through all the most common problems and teaches us how to solve them.

Tim See is a funny guy – his ceramics students must love him. He has created his own descriptive language for how clay should look on the wheel. The ideal? A gumdrop shape. This is a medium-sized mound that is slightly taller than it is wide, is wider at the bottom, and has a nicely rounded top. Just think of the candy – you can picture it!  He compares the ideal “gumdrop” with problematic shapes: the ramp, the mushroom, and the volcano.

Common problems with centering clay:

• Problem: The clay was never in the center of the wheel to begin with
• Solution: Stop. Pick up the clay and move it to the center. Don’t try to center from off-center! It will never wor

• Problem: The clay isn’t sticking to bat.
• Solution: Make the bat slightly damp. It shouldn’t be wet, but just damp enough to create a bond between the bat and the clay. Then, give the clay two quick slaps to make sure it adheres solidly

• Problem: I keep pushing the clay off the bat. (Pushing the clay hard from one direction will always push the clay off the bat.)
• Solution: First, use a flexible metal rib to scrape the slip from the bottom of the ball of clay. Then, a rubber rib to remove excess slip from wheel head. Finally, put the clay back on the bat. Be sure when you’re centering to use your right hand as a stabilizer or a “retaining wall.” This will keep you from pushing your clay off the bat.

• Problem: a “ramp” at the bottom of the clay
• This  is caused when hands are pushing into the clay slightly above where the clay meets the bat, creating a sloped base rather than a straight wall
• Solution: use a finger to compress the slope or “ramp” back into the clay, and then center as usual
• Problem: a “mushroom” at the top of the clay
• This is caused when the potter pushes down on the top of the cone without containing it or creating a “retaining wall” with the right hand.
• Prevent: be sure to have strong pressure with the right hand
• Problem: a “volcano” in the top of the cone
• This usually happens when you push the cone down too far, creating a low patty of clay on the wheel. Then, in the coning up process, the clay on the outside moves up higher than the clay in the center of the patty, creating an inverted center, or a “volcano”
• Solution: push down just around the edge in order to get rid of the volcano, then compress the clay, and continue centering.

Final step: get in the studio and practice centering clay!

Janis Hughes, Evolution Stoneware

Pottery – How to Center Clay on the Wheel

Janis Hughes, a former chemical engineer who now runs a successful pottery studio, shares her own how-to for centering.

She demonstrates a simple process that begins with 3 pounds of clay on a lightly moistened bat. She pats the clay down, pressing hard to be sure that the clay is secured to the bat. (Have you ever seen clay fly across the studio because it’s not attached to the bat? You don’t want to!)

In her centering technique, Janis pulls a tall cone. She notes that in pulling a cone, the potter must only center the top part of the cone, and incrementally move down, rather than centering all three pounds of clay at once.

To do the cone, she gets her wheel spinning quickly, wets the clay, and uses both hands to symmetrically squeeze-pull the clay up into a cone.

Next, she uses the palm of her left hand, right below the thumb, to push the clay back down. Because of back pain, Janis prefers to throw standing up. In order to anchor her right arm, she presses her elbow against her abdomen for stability. (Seated potters can anchor their elbows against their hip bone, and rest against the splash pan.)

Janis pulls the clay up into a cone and pushes it back into a disc three to four times until it is perfectly centered.