Ceramic Clay

Step 1: Choosing your clay - you may prepare raw dug up clay or much preferred material for consistency purchase commercial clay.

Taking into consideration the temperature needed to turn clay into ceramics by way of a kiln, it is important to know the minerals that are present within the clay paste. (You can either use a beginner's chemistry set or preferably refer to your local yellow pages for experts in this field.) Keep in mind, certain materials need very high temperatures to turn. Please read information on firing temperatures for commercially prepared clays below for an idea of choosing the right temperature to turn your freshly prepared clay into ceramic.

- If you prefer to dig up and prepare your own clay, you can follow the guidelines below for best product:

a) Freshly dug up clay will have impurities such as plant material, stones, insects, even air pockets. Let your clay air dry before breaking it up for cleaning.

b) Next, make sure the dried clay is in small pebble like pieces. Use a hammer, mortar for grounding these pieces into powder. To get the right consistency for the next step, make sure to weight your powders in a plastic bag and set aside.

c) Third, Get a bowl, pure the powdered clay in bowl and slowly pour water to form a paste. Use a wooden spatula to knead. If the powder floats or does not seem to mix with the water, let it set for a while before kneading again. Remember it must form a thick paste. If it does not, possibly too much water was added or not enough powdered clay.

d) Fourth, the cleaning process is about to begin. Press your clay paste through the your 80-mesh sieve to remove all impurities.

e) Place your cleaned clay onto to a plaster bat and smooth. The clay will begin to harden, you will need to move the paste around frequently to prevent hardening.

f) Using a strong flat stick remove the stiff clay from the plaster bat by peeling it off. Now you can knead your clay for modeling and firing.

- If you prefer to purchase your clay it will come in the following form to choose from:

a) Earthenware - red or white (kiln fires from 1830 to 2160 degrees Farenheit);

b) Stoneware - beige to white (kiln fires from 2190 to 2370 degrees Farenheit);

c) Porcelain - white (kiln fires from 2340 to 2460 degrees Farenheit);

d) Grogged stoneware - slate (kiln fires from 2190 to 2340 degrees Farenheit);

e) Raku body - slate (kiln fires from 1830 to 2340 degrees Farenheit); or

f) T Material - cream color (kiln fires from 1830 to 2370 degrees Farenheit);

Unfired clay is quite flexible. By kneading and handling it you can determine what that lump of clay is best suited in making. Look for shrinkage rate, and strength to determine durability.

Primary clay is extremely pure however it is not very pliable.

As an FYI, there are about 6 types of clay:

Red clay - very common to find. Its high iron oxide mineral content gives the clay its rich red color as well as makes it very easy to use.

Fire clay - can be fired to extremely high temperatures. Has a beige to medium brown color when fired. Usually found near coal seams.

China clay - used as glaze with other clay products. It is considered as primary clay meaning that it has minimal pliability.

Ball clay - extremely flexible, but breaks easy. It has to be combined with other types of clay to maintain its strength, shape and durability. Commonly used for porcelain and decorations.

Bentonite -Small amounts are combined with primary clay such as China clay to make it more pliable for molding.

Stoneware clay - Rare. This is high mixed mineral content which when fired turns gray to white.

Step 2: Your clay is not ready for kneading. (This includes both freshly dug clay that has been cleaned and commercially bought clay.)

a) Place your clay on an absorbent firm surface for kneading and throwing the pockets of air out. Take a wire and cut clay in easily handy wedges. Pick up 1 piece of clay at a time, with cut edge facing you, heartily throw or slam clay on bench to remove pockets of air. (It is extremely important that no air pockets are present in the clay so as to prevent explosions, or other mishaps that can occur if clay is firing in kilm.) Continue to knead, slam and pivot clay until all sides of clay are thoroughly kneaded. Repeat about 10 times or more to be sure. As a check at the end of kneading, use your wire and cut the clay in half. Take a look to make sure the surface is completely smooth. It should not have bumps, lumps, or wholes. It should be absolutely smooth.

b) Use a damp sponge and wet your pottery wheel lightly so that your clay will adhere but not slip.

c) Next, slam a ball in the center of the wheel. With both hands lightly on clay use forward and backward motions to see if clay is sticking to the wheel. If the clay is slipping or sloshy, wipe moisture off wheel. Turn wheel on or begin kicking wheel. Place both hands steadily on either side of clay and begin pushing inward slightly and upward. The clay will resemble a cone.

d) At the top of the cone, use your thumb to flatten and eventually use one hand;makes sure the other hand supports the sides of the clay. While the wheel is turning, use 3 fingers with the flat hand at the top middle of the cone to form a pocket. Remember to keep supporting the sides. You will see a bowl forming. Now both your creative hand on top or by now in the middle of the bowl and on the side hand are working in unity. How you wish your bowl to appear is part of the creative process.

When done, use wire to remove clay bowl from wheel and place on drying rack. When bowl is completely dry it is now ready for the kiln.