Introduction to ceramics What you need to know to get started…

Clay is…..  Weathered, decomposed Granite (rock). A Clay Body, is pure clay mixed other materials to make a desirable colour and texture of clay.  Earthenware: the type we will use. Fired at C comes in red or white This is a “LOW FIRE” clay. Other clays are fired much hotter!  Stoneware Clay: fired at C.  Porcelain: Fired at C. Very fine clay. When it is fired it looks almost translucent.

Most clay objects are mass produced using casting slip and a mold “slip” is liquid clay. Molds are made and the slip is poured in. Many identical molds can be made and this is the way ceramics can be mass produced. Video link:Video link: casting a cup Video link: Casting

Clay can be formed on the potters wheel A lump of clay is magically transformed into a vessel Video clip: tips for Throwing a Tall cylinder

Clay can also be formed using “HAND BUILDING TECHNIQUES”  No wheel is required.  The results are unique and equally valid  Technique #1:Pinch Pots Pinch Pots are created by inserting your thumb into a small clementine sized ball of clay. Slowly pinching in 3 rounds to thin the walls to an even thickness.

Technique #2: Coil  “worms” of clay are rolled to an even thickness and stacked one on top of the other to create any type of vessel you wish.

Technique #3: Slab  After wedging, clay is rolled out into a “sheet” that is even thickness.  It can be made into a variety of things from a mug, bowl, vase, platter… These pieces have been textured when the clay is still moist

Process: working with clay Air OUT Moisture IN Air Out Wedge the clay to rid it of air. Trapped air will cause your piece to blow (up) or at lease break. Moisture in : While working with your clay, keep it wrapped in plastic. Then it will be workable the next day. Otherwise you will have to start over.

Process:  Build your piece: 2-6 days  Let it dry: 1-2 weeks (covered at first so it dries slowly) At this point your potter is called GREENWARE. It is very, very delicate because the moisture is leaving it and it is dry an fragile.

Process: First Firing:Bisque  When your piece is TOTALLY DRY, your teacher will place it in the KILN  This is the first, or BISQUE firing  Your clay will harden and SHRINK by 15%

Kilns: so many different types  A kiln is a heating chamber for pottery  You can heat by electricity, wood… A typical oven cooks at 350 degrees Fahrenheit/ 176 C. Our kilns reach 1200 C or 2192 degrees Fahrenheit A hot day is 32 degrees C or about 90 degrees Fahrenheit

A firing mould in Africa A tile kiln A charcoal kiln Wood firing kilns

Safety in the ceramics studio: The Kilns  They are very hot. Don’t touch them or place anything on them. Assume they are ON.  Fumes: firing pottery gives of a smell. We have an EXHAUST HOOD above the kilns to take away fumes.  There should be no physical “horseplay” in the studio. No pushing, shoving, tripping. Someone could fall into the kilns and be burned. Any behaviour such as this will result in losing privileges in the studio.

Colour on Pottery  We use two kinds of colourants on pottery  #1: UNDERGLAZES :  They can be put on greenware or bisqued pottery  You may mix them and use them like paint  They fire to a MATTE surface  If you want them to be shiny you must put a clear glaze over them and fire a second time.

#2: Glazes  Glazes are applied AFTER the bisque firing  They are colour plus shine all at once  They should not be mixed together  Some are opaque and some are translucent. Matte glaze: not very shiny Glossy Glaze: shiny

Second firing: glost/glaze  Once the piece has been glazed with its final coat, it must go into the kiln a second time.  The process from start to finish is about 3 weeks, including building, drying, firing, glazing, firing….fini!

Other safety concerns  Sharp tools: be careful using exacto knives and b3knives. Use common sense  Electric shock: often we will have hair dryers out to speed up drying. NEVER, NEVER let them touch water.  Silica: Silica is a component of clay. When it is moist, it is not a problem. As clay dries and becomes dusty, it is easily inhaled. ***CLEAN CLAY UP WITH MOIST SPONGES*** DO NOT SWEEP OR BLOW DUST AROUND***

Finally  In order for us ALL to enjoy this class, we have to agree to clean up after ourselves always, and to help others when asked.  Clay is messy. Tools get messy. Hands get messy. Rolling pins get messy. It all has to be cleaned before being put away. If you do not clean it and you put it away dirty, the clay dries, becomes dusty and then poses a health risk to everyone. Please do your part and help others when possible.