American Raku. RAKU RAKU HISTORY Raku Pottery was developed in Japan in the early 1500s as the...

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American Raku

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Transcript of American Raku. RAKU RAKU HISTORY Raku Pottery was developed in Japan in the early 1500s as the...

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American Raku Slide 2 RAKU RAKU HISTORY Raku Pottery was developed in Japan in the early 1500s as the Ceremonial Tea Ware of the Zen Buddhist Masters. The word Raku signifies enjoyment of freedom. It was preferred by the Masters because of its humility, tasteful unpretentiousness, simple naturalness, and its deliberate avoidance of luxury...all very important to the Zen philosophy. Seldom watertight, Raku is actually a very poor choice for a casserole or a flower vase; it is pottery without utility or function. It is a low-fired ware with lead based glazes, and will only hold water for a short period of time. Raku must be approached with a different criterion in mind, like a painting or a symphony. According to the Zen Masters, its elusive, subtle, yet vigorous beauty is Raku's only worth. It is valued because it is believed that the Spirit of the Maker is embodied in the form and revealed at the foot, which is traditionally left naked (unglazed). It is believed that if we are alert to ourselves, in contemplating the Raku form, we will recognize in it our own Spirit and Meaning. The style of pottery was popularized in the 1950s in North America when American artist Paul Soldner adapted the process creating beautifully and uniquely colored items that were collected and used in homes as art pieces. The ancient art of Raku pottery has been used in Japan for centuries. These lovely pottery pieces were used in traditional Japanese tea ceremonies. Invented by a 16 th century tile maker named Chojiro, these hand molded tea bowls were fired and glazed forming the rustic yet elegant look that has been passed down for 15 generations. Slide 3 Raku Pottery is earth derived...the firing process is unique and daring, and in the eyes of the Zen Masters, the process truly reflects the most fundamental rhythm of enlightened life. A once-fired (bisque), unglazed pot is first coated with glaze and placed into kiln. The kiln is then heated to about 1,800 F at a fast rate. It is this first tremendous heat shock which often causes a pot to explode or to develop large "body cracks" in the clay walls. If the vessel survives this shock, almost immediate metamorphosis begins. The entire vessel glows like red-hot coal, and the glaze melts into a sheet of liquid glass. At this point, the pot must endure a second shock as the potter uses tongs to remove the glowing mass from the inferno. As the cools air outside the kiln hits the glowing vessel, the severe temperature change produces the cracks in the glaze. These cracks are highly prized as characteristic of traditional Raku Pottery -- they are the "proof-marks" of the earthenware's having survived this dramatic trial by fire. Upon leaving the kiln, the glowing pot is placed directly into an airtight container ("reduction chamber") filled with leaves, sawdust, or the like, which turns the naked clay foot black and highlights the valuable cracks in the glaze. As if all this were not enough, the vessel (often still over 1,000 F) may then be plunged into cold water to halt the process. And so the cycle of earth, fire, air and water is complete. Raku is a daring process, and a great many pots do explode during some phase of the firing. Those that survive the ordeal -- the test of fire -- are blessed. A portion of the Raku history provided by the Lavey Pottery Studio RAKU PROCESS Slide 4 Clay body (noun) refers to the actual clay mixture that is used in forming objects. It might only have one specific type of clay in it, but it is more likely to consist of a mixture of different types of clay. examples: porcelain, stoneware, soda clay, B-Clay high fire clay bodies, cone 10 is fired to 2335 degrees. terra cotta, and raku are low fire clay bodies - Please put raku scraps in the low fire recycle garbage can. Raku is fired to 1800 degrees We must use a clay body that will withstand rapid heating and cooling. That is why we use a raku clay body, a low fire clay body. Types of clay When we make conventional pottery, we know that once the piece is glazed and put in the kiln the creative part is finished, except of course for a skillful firing. Raku firing, however, extends our creative involvement as far into the process as we care to go. Our eyes are always on the piece, judging, determining, deciding, and altering. We end the firing when we see fit, without the aid of cones or other temperature-measuring devices. We alone determine the next steps. In addition, the rules or conventions in raku change as your expectations change. Raku is usually more than a one person event, so you must have helpers to facilitate the firing. ~ Steven Branfman Raku, A Practical Approach, 2 nd Edition ~ Slide 5 BISQUE FIRING The first firing of clay is called bisque firing. The resulting pottery is called bisque ware. Bisque firing serves the purpose of giving the pot considerably more strength than it has when it is simply dried clay (greenware). This allows the potter to handle the pot more readily without fear of breaking it. Bisque firing still leaves the pot porous enough that it can pick up glaze from a suspension of blaze material in water. Different potters bisque fire to different temperatures (or cones), but a typical firing would be from 1700 to 1800 degrees Fahrenheit. Greenware (noun) is the term given to clay objects when they have been shaped but have not yet been bisque fired, which converts them from clay to ceramic. Greenware may be in any of the stages of drying: wet, damp, soft leather-hard, leather-hard, stiff leather-hard, dry, and bone dry. Examples: Greenware is very fragile, and must be very carefully loaded into the kiln for its first firing. Slide 6 Glazing Raku has some glaze effects that are somewhat typical. These include metallic glazes, luster glazes, and other glazes that are effected by the reduction atmosphere in the combustion chamber. Married with the smoked aspect of the ware, raku pottery is often easily distinguished from other types of pottery.reduction atmosphere One of the other interesting aspects is the change a single glaze can show across the surface of a pot. For example, a glaze colored with copper can move from blue to red to a metallic copper sheen. These changes occur due to the change in atmosphere in localized areas. Popular raku glazes at The Ceramics Center include: raku magic, white crackle, dolphin blue, Kelsey's pear and turquoise crackle. Wax can also be used to block out areas that you want black. I waxed off the leaf shapes and the top of the pot on the right. I put the pear glaze over it and made sure to wipe the glaze off of the wax before firing. Slide 7 This is the new permanent raku kiln at The Ceramics Center The trash can kiln is very popular because it is inexpensive and can be transported easily. The kilns are fueled by propane. Firing in the raku kiln Slide 8 The kiln gives off tremendous heat as you can see. We must protect our eyes when looking into the kiln to check the stages of the glaze melting. Wear shoes to protect your feet when firing - no sandals please. Slide 9 Reduction Reduction (adjective) refers to a kiln atmosphere which does not have enough oxygen in it to completely consume the fuel as it burns. Due to this deficiency, the flame pulls oxygen molecules out of the clay bodies and glazes, changing their character. Reduction can be also be used to describe clay bodies and glazes that are especially developed for reducing atmospheres. Slide 10 Shapes that work best in raku! Vertical pots Pieces that have curves An orb shape We will not fire tiles or flat objects in raku. Slide 11 The raku process still amazes me! When I am creating, I keep in mind what areas I want to leave black. Try to design your piece with an area that will incorporate black from the reduction process. Happy creating!