Bat trang ceramic production procedures

1. Raw ceramic making 2. Decorating and glazing 3. Firing According to the generation after generation experience in Bat Trang ceramic village : “Nhát xương, nhì da, thứ ba dạc lò”

Reference: • From artisan Tran Do • Wikipedia website • Website: “battrang.info”

1) Earth selection - Selection of earth (including kaolin and clay) is the most important, it is taken from Quang Ninh province and Chi Linh district in Hai Duong province.

- Ceramic production centers must have earth sources for on-site exploitation and production.

- Bat Trang ceramic village was selected to be a ceramic producing centre with a white clay source nearby.

2) Earth processing and blending Earthen materials have many impurities; therefore, different earth processing methods need to be adopted for ceramic production.

Bat Trang uses the traditional earth processing method by steeping earthen materials in water tanks, including 4 tanks at different height levels: + First tank: “Stirring tank” is normally placed at a high position to steep clay in water. The steeping takes 3-4 hours until the earth turns into a liquid mixture.

Then, pour the mixture into the second tank. + Second tank: “Deposit tank” or “Filter tank”. In this tank, the clay starts depositing and several impurities (esp. organic composition) float above and will be eliminated.

Then, the deposited substance will be moved to the third tank. +Third tank: “Drying tank”, the earth is dried for 3 days. Then, the earth is moved to the fourth tank. +Fourth tank: “Fermenting tank”. Iron oxide (Fe2O3) and other impurities are eliminated during fermentation. Longer fermentation offers better quality.

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3) Shaping Bat Trang Village adopts the handbuilding method, shaping ceramic wares on a wheel.

Both men and women can be good at shaping Earth conditions ahead of being placed on a wheel + Clay needs to be well-kneaded by hand. + Clay is then rolled into coils and put on a wheel and the craftsman makes the shaping by hand Source: http://www.dthoi.com/forums/showpost.php?p=38701&postcount

4) Drying and refining Drying: The products are dried in the sun or by machine.

They are kept to not cause any cracks and defects. The products are dried on the shelves in cool places.

Now almost families perform the drying in the kiln. The temperature is increased slowly for gradual vaporization.

Refining + Placing products on a wheel: + The craftsman needs to cut and trim excessive parts, refining defects, sticking separate parts of product such as spout, handle‌, drilling holes on products, improving decorative patterns and smooth the surface.

Source: http://vi.wikipedia.org/wiki/G%E1%BB%91m_B%C3%A1t_Tr%C3%A0ng

1) Drawing - Bat Trang ceramic craftsmen use brush es to draw decorative patterns directly on products.

- Other decorating methods with strong artistic effects

2) Glazing - Ash glaze is the special of Bat Trang ceramics, besides brown glaze.

- During the 15th century, Bat Trang ceramic makers produced the famous blue and white glaze. The glaze creates color at the temperature of 1250 °C. - Cracked glaze appeared in the 17th century Brown glaze

Blue and white glaze

Cracked glaze

3) Glazing - Upon being completed, products are shortly fired at low temperature and then being glazed or it they may be glazed then being fired afterwards.

- Before glazing, a layer of glaze is covered to reduce the pottery colour.

Taking into consideration features of each type of glaze: + Glaze concentration + Weather + Sophisticated level

- Glazing technique: + Spraying glaze + Pouring glaze onto large ceramic surface + Dipping glaze onto small ceramic surface + Brushing glaze is a popular technique

+ Revolving glaze + Casting glaze 4) Refining glazed products - Refining products before being fired in the kiln - Checking glaze defects to be removed.

The key stage in determining success or failure of ceramic wares - Kindling the fire is very holy for ceramic craftsmen. + The oldest craftsman would light 3 incense sticks to express gratitude to heaven and the Fire God. - The temperature in the kiln is gradually increased to the highest level and is slowly reduced when ceramic wares are finished

Ceramic making life of artisan Tran Do Artisan Tran Do is the 18th generation of the ceramic making family Tran and has special traits: The great grandfather of ceramic making who lived 700 years ago has given artisan Tran Do valuable sleeps with the instructions and guidances of creation of glazes and earths, which couldnâ€&#x;t be created without the great grandfather.

Artisan Tran Do has had to wake up by the kiln gate to keep a fire in the kiln at many nights. He had many narrow escapes from death as he slept by kiln and let fire spread outside. It is thanks to the voice and shouder taps of the great grandfather.

1)

Kiln a) Frog kiln: Frog-shaped - Length: 7m, width: 3-4m; kiln gate width: 1.2m, height: 1m - Flat kiln bottom, arch height: 2-2.7m.

- Side door: 1m wide 1.2m high: supporting kiln and unloading products - The kiln has 3 straight stacks in 3-3.5m height.

b) „Danâ€&#x; kiln: appeare in the middle 19th century - Length 9m, width 2.5m, height 2.6m - Kiln gate width: 0.9m, height: 1m - Divided into 10 equal departments

1)Kiln (cont.)

c) Ovary kiln or dragon kiln: appeared in the early 20th century.

- Divided into many segments, from 5 to 7 segments

- Length 15m - Inclination of kiln axis -

Kiln temperature : 13000 C.

1) Kiln (Cont.):

c) Box kiln or vertical kiln: appeared in the 1965s.

- Height: 5m, width 0.9m - Built with refactory bricks - Two gates, simple structure, covering small area, reasonable price, - Highest temperation: 12500C.

1)Kiln (cont.) c) Shuttle kiln or namely gas kiln and Tunnel kiln or namely continuous kiln: has apperated lately.

- Fuel: gas-fired or oil-fired - Temperature is measured by pyrometer and adjusted semiautomatically or automatically.

2) Firing box: In the past, the kiln had square tiles assembled to create a firing box The tiles in the box can be as hard as porcelain upon reaching the high temperature.

The finished tiles are well-known Bat Trang tiles.

Firing box: Made of refractory clay Dark brown and mixed with tile fine or finely ground and broken firing box (called „Sa Motâ€&#x;) - Water is added and the mixture is well-kneaded. It is then brought to make a firing box or to make the assembling tiles.

Firing boxes are made in cylinder shape to make fire exposure equally to wares.

Firing boxes can be used from 15 to 20 times.

3) Fuel: - Frog kiln: using straw, rice stubble, bamboo in combination with fire wood.

- Shaft kiln: using dust coal, wood for kindling

4) Kiln Piling: Each type of kiln has different structure; therefore,the kiln piling has particular characteristics: 1) Frog kiln: arranging products from the back to the gate.

2) „Danâ€&#x; kiln: arranging from the second department to the tenth department 3) Ovary kiln: arranging products from the second department to the tenth department 4) Box kiln: products are placed in the firing box in cylinder shape without cover and are piled from the bottom to the top. Surrounding the kiln wall and blank space are placed with coal balls

5) Firing - The firing process is similar amongst frog kiln, „dan‟ kiln and ovary kiln and craftsmen can control the firing - For „dan‟ kiln, the kindling may take half of a day. Fire is kept to a small size at the large ovary for drying the kiln and products inside. The fire is made to grow larger eventually up to the fourth department and then the fire feeding is stopped. +The burning is quicker in the last stage +After burning, kiln gate and holes are closed for gradual cooling +It takes 2 days 2 nights to cool the kiln, then the kiln is left open for 1 day and 1 night before taking out the finished products.

- For vertical kiln, the firing is very simple. It is made when the fuel feeding is completed. The firing ends when coal in the kiln is completely burned. +The time from kindling to the end takes 3 days and 3 nights