5.2: Centering- The Foundation of Wheel Throwing
- Page ID
- 299294
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Centering clay on the wheel is foundational to successful wheel throwing. This subchapter outlines techniques and exercises to master centering, addressing common challenges and how to overcome them. The importance of consistent centering in achieving symmetrical forms is underscored, along with troubleshooting tips for off-center clay.
Techniques for Centering Clay on the Wheel
- Step 1: Coning Up and Down: Begin by coning the clay upwards into a tall shape, then pressing it back down into a squat form. This aligns the clay particles and prepares it for centering.
- Step 2: Anchoring Hands: Use one hand on the side of the clay to stabilize it while the other hand presses downward to center the clay. Keep your elbows tucked against your body for added leverage.
- Step 3: Gradual Pressure: Apply steady, even pressure to avoid pushing the clay off-center. Too much force can create wobbling or cause the clay to detach from the bat.
- Step 4: Visual Check: Watch for a smooth, even rotation. If the clay appears to wobble, adjust by applying gentle corrective pressure.
Here's a step-by-step guide to centering
1. Prepare Your Clay
- Wedge the Clay: Begin by wedging your clay on a work surface to remove air bubbles and ensure a uniform consistency. This kneading process also aligns the clay particles, which helps in the centering process.
2. Place the Clay on the Wheel
- Position the Clay: Place your wedged clay in the center of the bat (wheel head) as closely as possible. Use a firm motion to slap it down, ensuring it sticks to the bat.
3. Wet Your Hands and the Clay
- Lubricate: Wet your hands thoroughly with water or slip (clay mixed with water) to prevent the clay from sticking to your hands, which could cause it to pull off-center.
4. Start the Wheel
- Begin at a Medium Speed: Turn the wheel on at a medium speed. Too fast can be difficult to control for beginners, and too slow may not provide enough centrifugal force for effective centering.
5. Cone Up
- Press and Lift: Place your elbows into your sides to create stability, and press your hands into the clay. Use your left hand (if right-handed) to press on the side of the clay towards the center, while your right hand presses down on the top. This pressure should cause the clay to rise into a conical shape. The aim here is to align the clay particles and begin the process of centering.
6. Cone Down
- Push Down: With the clay coned up, keep your elbows anchored to your sides for stability, and use your palms and fingers to push the clay down into a squat, more centered shape. The left hand can provide inward pressure to assist in maintaining the clay's position on the wheel, while the right hand works from above to push the cone down.
7. Repeat the Process
- Cone Up and Down: Repeat the coning up and down process several times. This action helps to align the clay particles and ensures the clay is thoroughly centered. Each time, the clay should become easier to control and more centered.
8. Final Centering
- Smooth and Center: Once the clay feels somewhat centered, place one hand on the side of the clay and the other on top, applying gentle, steady pressure. Your hands should work in unison to prevent the clay from rising or falling. The goal is to have the clay spin smoothly with no wobble.
9. Check for Center
- Visual and Physical Check: Lightly touch the top and side of the spinning clay with a fingertip. A centered clay will feel smooth and even, with no bumps or vibrations. If you detect a wobble, wet your hands again, and apply pressure to correct it.
10. Secure the Base
- Seal to the Wheel: Finally, with the clay centered, use a sponge or your fingers to create a slight groove at the base of the clay where it meets the bat, and compress the clay towards the center. This step seals the clay to the bat, preventing it from sliding or wobbling when you begin to open and shape it.
Centering is a skill that improves with practice. Don't be discouraged by initial difficulties; even experienced potters sometimes struggle with centering, especially with larger pieces of clay. Patience and persistence are key.
Troubleshooting Off-Center Clay
- Correcting Mid-Throw: If the clay becomes off-center during throwing, stop shaping and re-center by applying pressure from the top and sides.
- Identifying Issues Early: Pay attention to signs like uneven spinning or a wobbling rim and correct them immediately.
- Checking Tools: Ensure the bat is securely attached to the wheel head and free of debris, which can contribute to off-center clay.
- Avoiding Dry Hands: Keep your hands and the clay well-lubricated with water or slip to maintain control and prevent jerking motions.
Centering clay on the potter's wheel is a fundamental skill in ceramics, crucial for creating symmetrical pieces.
Common Centering Challenges and How to Overcome Them
- Wobbling Clay: Often caused by uneven pressure or poorly wedged clay. Correct by coning the clay up and down multiple times to realign the particles.
- Sliding Clay: If the clay slides off the wheel, it may not be securely attached. Re-center it by pressing firmly and using slip as an adhesive.
- Off-Center Start: Begin with the clay positioned as close to the center of the wheel as possible before turning it on. A misaligned start makes centering much harder.
- Overworking: Avoid excessive coning, which can over-wet the clay and weaken its structure.
Exercises to Improve Centering Skills
- Practice with Small Amounts: Start with small balls of clay (1-2 pounds) to build confidence and control. Gradually increase the clay size as you improve.
- Close-Eyes Technique: Practice centering with your eyes closed to develop a tactile understanding of the clay’s movement.
- Repeated Coning: Spend a session repeatedly coning up and down without moving to the next step. This builds muscle memory and improves particle alignment.
- Feedback from a Mentor: Work alongside a skilled potter who can provide hands-on guidance and corrections.
The Importance of Consistent Centering in Advanced Throwing
- Foundation for Complex Forms: Proper centering ensures stability and balance, which is critical for taller or intricate pieces like vases or teapots.
- Symmetry and Aesthetics: A centered base results in even walls and a well-proportioned final piece. Off-center clay can lead to distorted shapes.
- Efficiency: Once centering becomes second nature, you can focus more on shaping and creativity, speeding up your workflow.
- Structural Integrity: Poorly centered clay is prone to collapse or cracking, particularly during drying and firing stages.