Clay

1
Clay

• Pottery is a form of Sculpture

2
Five basic ways to work with clay

• Pinch
• Coil
• Slab
• Thrown (made on a potters wheel)
• Slip casting (Pouring slip into a mold)

Hand built pottery
3
Pinch method

• Clay is formed into a ball
• A finger is pushed into the ball
• The potter pinches the clay and works in a
  circular pattern around the ball increasing the
  size.

4
Slab Method

• Clay is patted down somewhat flat
• The clay is then rolled with a rolling pin,
  turning it over regularly to prevent warping
• Wooden guides on either side are used to control
  thickness
• The slab is then cut to the desired size

5
Slab continued..

• The edges of the clay are scored
• Slip is applied over the score marks to act as a
  glue
• The pieces are pressed together like a zipper and
  excess slip is removed

6
Thrown Method

• The clay is centered on the wheel
• The clay is then opened
• The opening is enlarged to form the vessel
• The shape is then refined
• Finally the bottom is trimmed

7
Slip Molds

• Slip (liquid clay) is poured into a plaster mold
• As the mold absorbs the water a thin skin is
  formed on the inside of the mold
• The extra slip is poured out
• When the clay is leather hard, the mold is
  removed and the form is cleaned up, dried and
  fired

8
Coil Method

• Make a base (not shown)
• Roll out the coils
• Attach coils of clay to the base
• Blend the inside of the coil to the base
• Stack coils creating height

9
Another idea working with coils

• Arrange the coils in a design
• Repeat the design and lay out in a pattern
• Blend the back of the pattern together, making it
  into a slab
• Attach to the rest of the vessel like a slab,
  scoring a slipping.

10
Coil Pot Parts

• Lip
• Neck
• Body
• Foot

11
Pots come in all Shapes and Sizes
12
What are you considering for your Surface
Treatment

• Incised Design Designs carved into the surface
• Applied Design - Designs scored and slipped and
  added to the surface
• Impressed Design - Designs that are pressed
  into the surface

13
Things to remember about clay

• Clay contains silica- wet not a problem- dry
  powdery clay can cause problems in your lungs if
  over exposed.
• Grog is fired clay that has been ground up to a
  powder, when mixed with clay makes it stronger
  and helps in the drying process
• Slip is watery clay used as a glue and can be
  added as surface decoration
• Air bubbles and moisture can cause clay to
  explode in the kiln
• Elasticity of the clay means it bends without
  cracking. The older the clay, the more elastic
  it becomes. Old clay is good clay
• Clay shrinks when it dries and again when fired.

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More things to remember

• Kneading clay increases elasticity, arranges
  particles, makes it more consistent
• Wedging continues the alignment process and
  removes air bubbles
• Leather hard is partially dry
• Greenware is dry
• Bone dry is dry and ready to be fired