Introduction To Clay

1
Introduction To Clay
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Clay

• Clay is formed by the decomposition of rock
  through the action of weathering.
• Impurities, such as sticks and leaves are taken
  out and the clay is then packaged for our use.

3
Wedging

• Kneading the clay with fingers and the heel of
  the hands in a rocking spiral motion, forces out
  trapped air pockets and helps to distribute
  moisture evenly throughout the clay.

4
Attaching clay
5
Scoring

• Scoring is the best way of attaching one piece of
  clay to another.
• If clay is not properly scored, it will fall
  apart either when drying or during the firing
  process.

6
Slip

• Slip is liquid clay. Slip is applied to scored
  surfaces and acts as a sort of glue to attach
  one piece of clay to another.

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Hand building
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Coiling

• Coiling is a hand building method in which walls
  are constructed with hand rolled, rope-like
  pieces of clay. The joints are then smoothed over
  to create a one solid piece.

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Slab Rolling

• Slab construction is another hand building
  technique, in which the clay is rolled out into
  flat pieces. The slabs are usually an even,
  consistent thickness and are then cut, scored,
  slipped, and joined together.

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Wheel thrownpottery
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Phases of clay
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Leather hard
When clay is leather-hard most of the moisture
has left the clay and it feels cool to the
touch. Leather-hard clay is still soft enough
to be carved into.
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Greenware
Greenware refers to clay that is dried and ready
to be fired.
If the clay is not completely dry before firing,
the moisture in the clay turns to steam and blows
its way out!
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Bisqueware
Clay that has been fired once and is ready to be
glazed.
15
Glazeware
Clay that has been brushed with pottery glaze
and fired a second time.
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Kiln

• A furnace used
• for firing ceramic
• products.
• In order for clay to
• become permanent, it
• must be fired at very
• high temperatures in
• a kiln.