Saggar

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Saggars in the Gladstone Pottery Museum
Saggars in use in the Manufacture nationale de Sèvres

A saggar is a ceramic, boxlike container used in the firing of pottery to enclose or protect ware in kilns. Traditionally saggars were made primarily from fireclay.[1][2] Saggars have been used to protect, or safeguard, ware from open flame, smoke, gases and kiln debris:[3] the name is a contraction of "safeguard".[4] Their use is widespread, including in China, Korea,[5] Japan and the United Kingdom. Saggars are still used in the production of ceramics to shield ware from the direct contact of flames and from damage by kiln debris.[6][7][8] Modern saggars are made of alumina ceramic, cordierite ceramic, mullite ceramic and silicon carbide.[9][10]

A Saggar Maker's Bottom Knocker was a job associated with the manufacturer of saggars in the UK,[11] a name considered sufficiently amusing for it to be featured on the television panel show What's My Line?.[12] The occupation is not needed with modern automated production techniques.[13]

Studio pottery use[edit]

From the 20th century studio potters have used saggars to create decorative ceramic pieces.[14] In this use saggars are used to create a localised reducing atmosphere,[14] or concentrate the effects of salts, metal oxides and other materials on the surface of their ware.[15]

Some pots may be carefully prepared for saggar firing. One method creates a smooth surface covered with clay slip, terra sigillata, which responds particularly well to the saggar technique. This slip covering may be burnished to achieve a gloss. Prepared pots are nestled into saggars filled with beds of combustible materials, such as sawdust, less combustible organic materials, salts and metals. These materials ignite or fume during firing, leaving the pot buried in layers of fine ash. Ware produced in filled saggars may display dramatic markings, with colours ranging from distinctive black and white markings to flashes of golds, greens and red tones. Porcelain and stoneware are ideal for displaying the surface patterns obtained through saggar firing. In addition to the use of saggars, some studio potters bundle pots and burnable materials within a heavy wrapping of metal foil.

References[edit]

  1. ^ 'A Study of the Properties of Saggar Mixtures. Part XVIII: The Use of Fused Silica as Grog in Saggar Mixes.' White R.P, Rigby G.R. British Ceramic Research Association.RP13. 1948
  2. ^ 'Kiln Furniture Mixes Containing Highly Refractory Grog'. White R.P, Rigby G.R. British Ceramic Research Association. RP161. 1952
  3. ^ http://www.ironbridge.org.uk/learning/resources/resources/ccm.pdf.
  4. ^ 'The Concise Oxford Dictionary of English Etymology'. T.F. Hoad. Oxford University Press. 1996. Retrieved October 14, 2009 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O27-saggar.html
  5. ^ http://www.clickkorea.org/arts/curator/file/1-6_A%20Brief%20History%20of%20Korean%20Ceramics.pdf
  6. ^ 'Extending The Useful Life Of Saggars'. Karpova N.G., Voitovich V.A. Glass and Ceramics. Vol. 37, No 12. 1980
  7. ^ http://amic.biz/Data%20Brochure/AMI%20Kiln%20Furniture%20%28Cordierite-Mullite-Corundum%29.pdf.
  8. ^ http://www.ikf-solutions.com/pdf/KF%20for%20TC%20CFI%20April09.pdf.
  9. ^ 'Development Trend Of Dense Alumina Saggar For Electric Materials'. Hayashi K. Ceram. Jap. 38, No.8, 2003. pg.561-563
  10. ^ 'Silicon Carbide Sagar For Firing Non-oxide Ceramics.' Sakaguchi M., Taskeshita S., Hirota T., Aratani K., Kawakami T. Refractories in the Ceramics Industry. Aachen Proc., 32nd Int.Colloquium on Refractories Aachen, 12–13 October 1989, pg.75-78 Verlag Schmid GmbH
  11. ^ http://www.adam-hart-davis.org/articles/Sagger-maker.htm
  12. ^ http://www.thepotteries.org/bottle_kiln/saggar.htm
  13. ^ 'Automatic Saggar Handling Plants'. Lippert J., GmBH & Co. Pressath, 1991
  14. ^ a b http://members.iinet.net.au/~potters2/newsletters/tas-potters-news-june-06.PDF
  15. ^ Cort, Louise. Seto and Mino Ceramics. University of Hawaii Press, 1992, p. 68