Chapter 2: Working with Clay

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Chapter 2Working with Clay

• Properties, Preparation, Tools

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Properties

• Plasticity the property of clay that allows it
  to change shape without tearing or breaking.
• Some clays are more plastic than others. Clays
  that have traveled farther as they developed pick
  up more algae and bacteria that make them more
  plastic.

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• Shrinkage the reduction in size of the clay mass
  that occurs when water in the clay evaporates
  during drying and firing.
• If the potter is not careful clay can crack as it
  shrinks. To avoid this let the clay dry slowly
  and remember that smaller pieces of clay dry more
  quickly.
• If a lid is made of wet clay to the size of a dry
  pot it will be too small.
• Wet length Dry length / wet length x 100
  shrinkage

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• Texture
• Texture is altered by how much sand or grog is in
  clay.
• Coarse clay is good for large scale work, medium
  for hand building, and smooth for throwing, bead
  making, and other delicate work.

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• Moisture
• If clay gets too dry it can crack but if it gets
  too wet it will not hold its shape.
• As you work with the clay your hands will
  naturally dry it out. It is important to always
  have a bowl of water at your seat.
• When not working with clay always have it wrapped
  air-tight in a plastic bag until you are finished
  with the piece.
• Clay can not be fired until it feels dry and
  warm. If it still feels cold then it is too moist
  to fire. ( If you do it will blow up!)

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Preparation

• Safety in the studio
• Wear protective clothing
• Capture clay dust with water
• Dont eat while in the studio
• Wear a dust mask when dealing with dry clay

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• Kneading
• This is the best way to work all the air bubbles
  out of clay and make the clay an even consistency
  for small hand building projects.
• Why do we get out air bubbles..because they will
  explode in the kiln!
• Wedging
• This is when you have to work the air out of a
  large piece of clay. (spiral or rams head)