INTRODUCTION TO CERAMICS Working with CLAY!!!

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. Some artists still dig up their own clay, but you have to know the difference between clay and just plain mud.

Working with Clay Clay Properties Plasticity-how well clay moves Shrinkage-our clay shrinks 15% Moisture-Keep your clay happy- keep it covered!!!

Three Methods… All Ancient… Hand building Three Methods… All Ancient…

Pinch Pots PINCH POTS are formed by quickly pinching and turning a kneaded ball of clay. It is important to get the clay an even thickness. One of the most simple hand building techniques.

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

SLAB ROLLLING Use of Slats is Important! Hand rolled in class- we do not have a fancy slab roller Use of Slats is Important! Slab construction is another hand building technique, in which the clay is rolled out onto flat pieces. The slabs are usually an even, consistent thickness and are then cut, scored, slipped and joined together. Best joining at the LEATHERHARD stage.

STAGES OF CLAY

SLIP Slip: Watered down clay in muddy form. Used as a “glue” to attach two pieces of clay together Can be used in moldmaking

Plastic Workable wet stage; molding stage; can recycle. At this point, it can still be joined to other pieces. Very flexible and won’t crack when shaped.

Leather-Hard Stiff and will hold its shape; can still be joined to other pieces. May be carved into but will crack if you try to shape it. Can still be recycled. Dark grey colour.

Greenware Bone-dry light grey colour; VERY FRAGILE. Can still be recycled. Kiln ready. Do not touch or move drying greenware clay!

Bisqueware Fired once in the kiln. CANNOT BE RECYCLED. Glazing or painting stage. Now you can handle your clay. Light buff colour.

Glazeware Result of a second firing. Make sure to put 3 coats of glaze on before it is fired to get good colour. Now your piece is waterproof. Note: You cannot mix regular paint and glaze!

KILN Furnace used for “firing” greenware/glazed bisqueware. In order to become permanent, clay must be fired at very high temperatures in a kiln. We fire anywhere from 1800-2000 degrees Fahrenheit. Caution the kiln gets HOT!!!

If Clay is not attached properly it WILL fall apart when it dries. Attaching Clay Using the 3 S Method

SCORING SCORING is scratching the surface of the clay using a crosshatching technique. You want more than light surface marks but not deep gouges that may become air pockets.

SLIP SLIP is liquefied clay. (clay with added water) Slip is applied to scored surfaces and acts as a sort of “glue” to attach one piece of clay to another.

SMOOTH The final step is to smooth the two pieces of clay together. You can use your finger or a wooden tool to do this. Ideally, you should not be able to tell that you have joined two pieces of clay together. They are now one piece!

Re-enforcement For extra strength when joining clay you can re-enforce a join with a coil of clay. Just remember to push it down fully from one end to another so that no air gets trapped! Important to do for large slab pieces

Wedging You only need to wedge your clay if it is not new from the box. Our clay comes pre-wedged. 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. You can also slam smaller pieces to get the air out. Don’t use clay unless it is new clay from box or unless you have wedge your clay!!! Air pockets make clay explode!

Blowing up your bunny is not very funny. What happened here? Clay was too thick Body was not hollow Did not have air vents!

IMPORTANT to REMEMBER!! Clay must be thoroughly covered up with a plastic bag to keep it from drying out.  This applies to works in progress and moist clay. Clay dust can be harmful if you are exposed to it for long periods of time, so keep your area clean, clay scraps off the floor and clean with water and a sponge. Clay can be no thicker then your thumb before you have to hollow it out In order for clay to stick together it MUST be scored and slipped together while the clay is moist or leather hard. Wedge any pre-used clay to remove air bubbles, achieve uniform consistency, and to line up the particles of clay. New clay from the box does not need to be wedged.

NEVER HANDLE OR TOUCH ANOTHER PERSON’S WORK EVEN IF IT LOOKS COOL! IMPORTANT to REMEMBER!! Trapped air can cause clay to explode.  So hollow out sculptural forms and put needle holes from the bottom so air can escape. Don't glaze the bottom of a piece.  Always wash the piece before glazing. Always handle your project with two hands at all times.  In other words BE CAREFUL it’s your hard work. Never lift pots by the rim or animals by the details NEVER HANDLE OR TOUCH ANOTHER PERSON’S WORK EVEN IF IT LOOKS COOL!