Objective: For students to become familiar with the vocabulary and techniques associated with clay hand building. Agenda –Warm Up : What is bas relief sculpture? –Get out a sheet of paper, put your name on it and number it 1-20 –Clay PowerPoint. Copy the missing answers down in your packet and place the packet in the tray at the end of the period. ** All art fees must be paid by next Monday or you will not get clay!! ***Bring a plastic grocery bag by next Thursday so your clay won’t dry out!

Ceramics Ceramics are objects made from clay. Clay is a result of the decomposition of igneous rock.

Properties of clay Shrinkage - The reduction in size of the clay mass that occurs when water in the clay evaporates during drying and firing. –Grog - crushed fired clay used as an additive to clay to reduce shrinkage. Grogs acts as a stabilizer to help clay dry uniformly. Plasticity - The property of clay that allows it to change shape without tearing or breaking. Moisture - All clay has moisture, as the moisture evaporates the clay gets harder to shape.

Clay Bodies –A clay body is the mixture of minerals and other ingredients that make up the composition of the clay type. –Two types of clay bodies. Vitreous clay Porous clay

Vitreous Clays –A non-porous material, whose particles meld together and become glass like when fired to high temperatures. –Glazing is mainly used for aesthetic (eye pleasing) and hygienic qualities. –Theses clays include Stoneware, Porcelain and Bone China.

Stoneware Used for functional ware and sculpture. May be gray, beige or brown.

Porcelain and Bone China Porcelain is a fine quality white clay; can be translucent after firing if the walls are thin enough Bone China is a hard white translucent clay.

Porous Clays –Porosity - the amount of empty space in the structure of the fired clay that makes it capable of absorbing liquids. –Types of porous clay. Earthenware

A very plastic clay body that is good for throwing on the wheel. It is porous and must be glazed to be functional.

Terra cotta A reddish brown low fire porous earthenware that is very strong after firing because of its high iron content. Usually used for pottery, sculpture and architecture. From the Italian, meaning “baked earth.”

Kiln A kiln is a structure built to fire clay at high temperatures. The chamber is the enclosed portion of the kiln where pottery pieces are placed for firing. Firing is the heating of pottery or clay to a temperature high enough to render it hard and durable. Fire clay is used in kiln production because it can withstand high temperatures.

Pyrometric Cones An object made of ceramic material with a specific melting point, used to show the temperature in a kiln during firing. When the specified temperature is reached the cone bends. Maturing temperature is the temperature at which the clay body reaches the desired hardness or when a glaze fuses to a clay body.

Bisque Fire A bisque fire is the first firing of a clay to drive out chemically combined water and materials prior to glazing. Bisque is ceramic ware that has gone through the first firing at a relatively low temperature. It is possible to over fire the clay. This happens when the temperature or the length of firing is increased beyond the ideal for a particular clay body or glaze.

Greenware, Leather hard and Bone dry Greenware is unfired clay objects. Leather hard is the stage between plastic and bone dry, when clay has dried, but still may be cut or joined. Bone dry is the stage of drying when moisture in the clay body has evaporated so that the clay surface no longer feels cool.

Glazes A glaze is a coating of glass that is fused to the surface of a ceramic piece. –Think of glaze as a thin coat of glass. A glaze fire is a cycle during which glaze materials are heated sufficiently to melt and form a glassy surface when cooled.

Oxides Oxides are compounds containing oxygen and other elements, used in making and coloring glazes and clay bodies. –Feldspar is a common mineral found in clay and glazes to add color.

Score and Slip Every time two piece of clay is joined, the surfaces that are to meet must be roughed up, this is called score. Slip is a suspension of clay materials in water. Slip is applied to the surfaces and then put together. The slip acts like the glue, you are essentially gluing two pieces of clay together.

Basic Techniques for hand building. Before an artist can begin, the clay must be kneaded or wedged to remove the excess air. –If air remains in the clay and it is fired, the clay will explode, also destroying the pieces around it.

Preparing the Clay Kneading Kneading is working clay on a surface with the palms of the hands to remove the air and obtain a uniform consistency.

Preparing the Clay Wedging Mixing and de-airing clay by cutting it diagonally and slamming the pieces together.

Extrusion The process of making shapes by pushing clay through a die.

Coil Method A coil is a rope like roll of clay. The coils are scored and slipped and placed on top of each other. Depending on the artist’s preference the coils can be smoothed or left alone.

Slab Clay is rolled out to an even thickness, and then cut to size. Once all the pieces have been cut they are scored, slipped and joined. A coil is added at the joint to add strength.

Pinch Method By inserting the thumb into a ball of clay and lightly pinching with the thumb and fingers while slowly rotating the ball in the palm of the other hand, a small pot can be rapidly made. (A base or foot can be added at the bottom for the pot to sit on, see far right).

Procedures for the clay There will be no THROWING clay or you will loose the privilege and will do book work. If clay lands on the floor, throw it away, it is now contaminated and may blow up in the kiln.

Procedures continued All tools will be wiped off with a wet paper towel before being rinsed in the sink. The desks must be wiped down at the end of every period. Do this with a wet paper towel to keep the dust from flying.

Projects Pinch pot –Two pinch pots are required. Animal vessel –optional Coil pot –optional Slab box –Optional Whistle –Privilege

Pinch Pots Two practice pinch pots will be made. One with a foot, one without. –We will practice kneading and pinching. –This will be a daily grade.

Animal Vessels choice one Using the pinch method an animal vessel will be created. Details will be added by score and slip. Any animal will do, but it must be an open vessel.

Coil or Slab pot choice 2 and 3 You will choose either the coil method and create a pot; or the slab method and create a box. It must have designs added to the surface. It can be decorated any way you choose.

Clay Whistles Using all methods a clay whistle will be constructed. The whistle must take the form of something, an animal or an object. Details may be added to the surface and carved into it.