5.3: Creating Basic Forms- Cylinders, Bowls, Plates
- Page ID
- 299295
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)The process of creating basic wheel-thrown forms is detailed, starting with cylinders as the basis for various shapes. Techniques for shaping bowls and throwing plates are covered, along with tips for managing thickness and trimming. This section lays the groundwork for more complex forms, emphasizing the importance of mastering these foundational shapes.
Step-by-Step Guide to Throwing Cylinders: The Foundation of All Forms
- Step 1: Center the Clay: Begin with well-centered clay. A cylinder requires precise centering as it forms the basis for most wheel-thrown shapes. Ensure the clay spins smoothly without wobbling.
- Step 2: Open the Clay: Using your thumbs, press into the center of the clay to create a hollow. Gradually widen the opening, leaving the base about 1/4-inch thick for strength.
- Step 3: Pull Up the Walls: Place one hand inside and the other outside the clay. Apply steady, even pressure to lift the walls upward. Work slowly to maintain an even thickness.
- Step 4: Refine the Shape: Use a rib tool to smooth the walls and define the cylindrical form. Keep the rim level by compressing it gently after each pull.
Techniques for Shaping Bowls from a Centered Cylinder
- Step 1: Open Wider: After centering, open the clay into a wider base to set the foundation for the bowl's shape. Keep the movement gradual to avoid distorting the clay.
- Step 2: Curve the Walls: Support the exterior with one hand while pressing the inside upward and outward to create the bowl’s curve. Use soft pressure to form smooth, flowing lines.
- Step 3: Prevent Collapsing: Slow the wheel and focus on even pressure. Compress the rim regularly to maintain structural integrity as the walls thin out.
- Step 4: Final Shaping: Use a rib tool to refine the curve and smooth the surface. A flexible rib works well for achieving gentle, continuous curves.
Throwing a Bowl
1. Opening the Clay
- With the centered clay spinning on the wheel, press your thumbs into the center to open it. Keep the bottom thickness in mind (about 1/4 inch is good).
2. Widening the Base
- Place your fingers inside the opening and begin to widen the base by pressing outward gently, keeping the wheel speed consistent.
3. Pulling Up the Walls
- Wet your hands. Place one hand inside and one outside the clay. Gently squeeze the clay while slowly moving your hands upward to raise the walls. Repeat as necessary to achieve the desired height and thickness.
4. Shaping the Bowl
- To shape the bowl, support the outside with one hand and gently press the inside against this hand to create the curve of the bowl. The shape can be refined by varying the pressure and speed of the wheel.
5. Trimming the Rim
- Use a wooden or metal rib to smooth and shape the rim, making it even and removing any excess clay.
6. Cutting and Removing
- Slow the wheel and cut the bowl from the wheel head with a wire tool, sliding it underneath. Carefully remove the bowl and set it aside to leather-hard before trimming the foot.
Throwing a Cup
1. Opening the Clay
- After centering, press down into the center with your thumb or fingers to open the clay, leaving a thicker base for strength.
2. Raising the Walls
- With fingers inside the clay and a sponge or your other hand outside, gently squeeze and lift the clay upwards to form the walls. Keep the walls even in thickness.
3. Shaping the Cup
- As the walls grow taller, support them from the outside and gently curve the inside to form the cup shape. Ensure the lip is smooth and even for a pleasant drinking surface.
4. Forming the Foot
- Use a trimming tool to define a foot ring at the base of the cup. This step can be done at the leather-hard stage as well.
5. Finishing the Rim
- Smooth the rim with a sponge or a rib, ensuring it is comfortable to drink from.
6. Cutting and Removing
- Slow the wheel, cut the cup free with a wire tool, and carefully lift it from the wheel to dry to leather-hard before trimming, if necessary.
Throwing a Plate
1. Opening and Compressing
- After centering, open the clay wide and shallow, keeping the base thicker. Compress the base with your fingers or a rib to avoid S-cracks.
2. Forming the Plate
- With both hands, gently pull the clay outward from the center, keeping the movement smooth and even to widen the plate. Keep the base compressed and flat.
3. Shaping the Rim
- Support the outer edge of the plate with one hand, and use the other to shape and lift the rim slightly. This defines the edge of the plate and prevents warping.
4. Smoothing the Surface
- Use a rib to smooth the surface of the plate, ensuring it is flat and even. This also compresses the clay further, which is crucial for plates.
5. Cutting and Removing
- Carefully cut the plate from the wheel head with a wire tool, and remove it using batts if available, to avoid distorting the shape. Allow it to dry to leather-hard before trimming the foot, if desired.
Tips for Throwing Plates and Wide Forms
- Step 1: Center and Flatten: After centering, press down firmly with your fingers to create a wide, flat base. Compress the surface with a rib to prevent cracks.
- Step 2: Define the Rim: Shape the edges by lifting or slightly flaring the rim to create a distinct boundary. A small ridge helps contain food or liquids in functional plates.
- Step 3: Maintain Uniform Thickness: Use a rib to smooth and even out the plate’s surface. Uneven thickness can lead to warping or cracking during firing.
- Step 4: Dry with Support: Allow plates to dry on a flat, porous surface like plaster to reduce the risk of warping. Cover loosely with plastic for even drying.
Thickness Control and Trimming Excess Clay
- Preventing Thick Bases: Use a needle tool to measure the base’s thickness while throwing. Trim excess clay from the bottom at the leather-hard stage to lighten the piece.
- Consistent Walls: Check the walls frequently by pinching gently to gauge thickness. Thicker areas can be thinned by repeating the pulling process with light pressure.
- Refining with Trimming Tools: Once leather-hard, use trimming tools to smooth and shape the bottom. A defined foot adds both stability and aesthetic appeal.
- Avoid Over-Thinning: Ensure that walls remain strong enough to support the piece during handling and firing. Pieces that are too thin are prone to collapse or cracking.