THE CHARACTERISTICS AND ARTISTIC ELEMENTS OF THE CONTEMPORARY WOOD-FIRED CERAMICS

Tony Yeh

The contemporary wood-fired ceramics which is to discussed in this article is not the so-called "the ceramics fired with woods" in a broad sense. It is a new conception of firing and making ceramics. Therefore the wood in this scope is not only a fuel, but also a "medium" and the effects from this medium is an important part which has been pursued and appreciated in the art of wood firing.

Although it has some similarities to those former wood-fired kilns and fuels, it has completely different techniques and ideas, especially the aesthetic points of view. It is more interesting to find that this method that was regarded as being rough and crude in the past has been reevaluated step by step in the past fifty years and, unexpectedly, the people have 9ained more lasting and true sustenance in the primitive and rough styles. CHARACTERISTICS OF WOOD-FlRED CERAMICS.

The most important difference of the ceramic works fired in wood-fired kilns from those of electric kilns and gas-fired kilns is that the ashes and flames from the burning of woods go directly into the kilns. The ashes fall naturally on the body and are fused into a natural ash glaze at the high temperature for a long time. It has warm colors, rich gradations and bold and energetic qualities. The very difference from the generally gorgeous and shiny glazes is its fired result that cannot be to be repeated and difficult to be expected. If in a side fired kilns , it has its specific directionality and the fired works have different surfaces because of the different firin9 effects on the front side and backside of the works. They send forth a simple, vigorous and primitive sense of beauty. It is the very reason that ceramic artists are fascinated with its beauty and have made strenuous efforts for their aspirations.

ROLE OF KILN

The structure of a wood-fired kiln is usually composed of four parts: fire box, chamber, chimney and flue. The principle of firin9 a kiln is as f0lIows; the woods burn in the fire box and its ashes, flames and heat go through the chamber and act on the bodies in the chamber before discharging from the chimney. So the focal points in the design of a kiln must conform to the following conditions:
1. beneficial to firing (incIudin9 heating-up and retaining heat)
2. beneficial to the imprints of flames and ashes on the body. 3. the discharging route of fire (inverse flame and direct flame)

The structure of a kiln is not merely a technological problem, it determines the discharging route of flames and the falling directions of ashes. To be more exact, the kiln will determine an unchangeable style of firing by the makers.

Different types of kilns have different characteristics and it is so much as that the same type of kilns have their own specific characteristics. Besides conforming to and controlling the kilns, our control over the performances of a kiln also includes our control over the firin9 effects. However, the different evaluations of the so-called "firing effects" are actually subject to the artists' subjective factors. especially when the creation is to be regarded as a starting point. Whatever happens, there must a comparatively appropriate level of control of a kiln and minimum effects of fallen ashes and flames because there is no need to firing in a wood-fired kiln without any ashes and marks of flames. An improper design of a kiln will lead to such phenomenon as follows: poor effects, inability to control, no way to heat up and retain a stable temperature, no fallen ashes and marks of flames.

STACKING

All the people who have fired gas-fired kilns and electric kilns have already got an idea that there be appropriate room between the bodies. The reasons are; first, the heat wiI1 circulate evenly and, second, it will not lead to the adhesion of the bodies with each other, Y6t the current practices of wood firing are not so and sometimes just opposite to the above-mentioned methods. Exactly speaking, stacking is the most important part of wood-fired creations, It determines the positions and degrees of marks by flames, The stackers must be cool-minded and deduce the flow of flames in the kiln to determine the most suitable position for each of the bodies. They must predetermine the best effects and have a full consideration of the air flow through every part of the kiln. As a result, stacking usually takes a great deal of time:a 3 cubic meters kiln usually takes a whole week for stacking. The main points for stackin9 are as listed below:
1. a good understanding of the characteristics of the kiln,
2. be clear about the effects to be gained and can be gained,
3. a full consideration of the hi9h interaction and connectivity between forming, stackin9 and firing
4. quantity and positions of side ports and the room of lateral firing (bigger or longer kilns)
5. height, pore size of flash walls(space between flash walls and bodies, adaptable for Deng kiln, Bourry Box or reserved flame kiln)
6. position of the rear flash walls, the sizes and positions of ports (stacking from front to the back for example of rifle kiln)
7. methods of field practices include stacking, hacking, inter-blocking of the bodies, effects of marks of rice grass ashes, arrangement of the flow of flames. and others.

FlRING AND FUEL

The fuel (wood) must be prepared as early as possible and it is better to get everything ready three months before firing because it is not as easy as to turn on an electric kiln or a gas-fired kiln. The sources of wood are very important and it includes a stable supply, quality and transportation. Many people seem to take more care of the varieties of woods and think that the pine trees could have created a specific color of ashes. It is certain that every variety of tree has its own property, but the firin9 effects depend on many factors which are quite perplexed. The influences that varieties of trees exert are not great. On the contrary, the quality of wood should be taken into more consideration, for example, the specific gravity of wood, sizes, desiccate, etc. Different stages of firing need wood of different qualities.

Most of the wood comes from the off-cuts from timber-yards. Don't be bothered about the varieties of wood and it wil1 be used so long as its qualities conform to our requirements. The reason of selecting miscellaneous trees is relative to both an environmental problem and a problem of costs. They are usually abandoned or sold as burning woods in batches. Such a selection will reduce the cost of fuel as much as possible. Moreover, the wood-fired kiln men All around the world have a common view: never to cut down trees for Kilns.

Selections of the qualities of wood differ from man to man and each quality has its own specific function. For example:
1. big (heavier) woods are selected as the base of keeping the heat;
2. thin (Lighter, drier) woods is quick to heat up and easy to raiseashes;
3. wet woods selected to produce special eff6cts.

"Firing process" is another key to f8jIure or success other than stacking. It is also the most fascinated and charming part of the wood-fired creation. An experienced kiln man usually makes a detailed plan of the firing process while stacking, such as days of the whole process, the highest point of temperature and the position and duration of permanent temperature, the cleanness and turbidity of the gaseous atmosphere, or the time and amount of feeding woods into side ports, etc. As important as the design of stacking, the design of firing process is a very important way to gain "the firing effects" and to demonstrate concepts of an artist to its fullest. Following the accomplishment of a detailed firing plan, the focal point of firing is to control the implementation of the firing process. Therefore, he should be cool-minded and keep abreast of the conditions in the kiln It is more important that he is quite clear about what he is doing now and what he should do. He will never be so nervous about temporary ups and downs of the temperature. In contrast, an inexperienced hand might become dizzy and forget what he should do. It is possible that he does not know how to observe the conditions of firing due to his inexperience, or he is even blind in feeding the kiln.

The firing can be divided into two parts: implementation of the planned process and observation of any real-time conditions and making responses. The first part is related to the artist's design of "the process". The comprehensiveness and rationality of the process design are the essential contents to be tested after each unloading. In contrast, for the second part, it is necessary to hire an experienced and acute kiln man to implement every step of the process. Every circumstance during the firing is sometimes very complicated, including various factors relative with man, materials, weather and the kiln itself. These factors mi9ht change the planned process and add variations to the fired results. Therefore, it is quite important to give priority to the general orientation to the firing target and make a prompt decision in any emergencies.