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Vitrified clay pipe (VCP) is pipe made from a blend of clay and shale that has been subjected to high temperature to achieve vitrification, which results in a hard, inert ceramic. VCP is commonly used in gravity sewer collection mains because of its long life and resistance to almost all domestic and industrial sewage , particularly the ...
The vibrancy that only underglaze was able to supply is now achievable with a variety of over-glazes therefore discounting the advantage that underglaze commercial production had. A well-known New York underglaze tile and pottery decorator of the 1940s, Carol Janeway (1913-1989), was diagnosed with lead poisoning after eight years of using a ...
[contradictory] This type of clay is water-soluble and unstable. Earthenware is clay that has been fired between 1000–1200°C or 1832°–2192°F. The firing makes the clay water insoluble but does not allow the formation of an extensive glassy or vitreous within the body. Although water-insoluble, the porous body of earthenware allows water ...
Blue glazes were first developed by ancient Mesopotamians to imitate lapis lazuli, which was a highly prized stone. Later, a cobalt blue glaze became popular in Islamic pottery during the Abbasid Caliphate, during which time the cobalt was mined near Kashan , Oman , and Northern Hejaz .
Glazes need to include a ceramic flux which functions by promoting partial liquefaction in the clay bodies and the other glaze materials. Fluxes lower the high melting point of the glass forms silica, and sometimes boron trioxide. Raw materials for ceramic glazes generally include silica, which will be the main glass former.
Though the recipe of tin glazes may differ in different sites and periods, the process of the production of tin glazes is similar. Generally speaking, the first step of the production of tin glazes is to mix tin and lead in order to form oxides, which was then added to a glaze matrix (alkali-silicate glaze, for example) and heated. [19]
Hard-paste porcelain was invented in China, and it was also used in Japanese porcelain.Most of the finest quality porcelain wares are made of this material. The earliest European porcelains were produced at the Meissen factory in the early 18th century; they were formed from a paste composed of kaolin and alabaster and fired at temperatures up to 1,400 °C (2,552 °F) in a wood-fired kiln ...
In such cases the first firing for the body, underglaze decoration and glaze is followed by the second firing after the overglaze enamels have been applied. The technique essentially uses powdered glass mixed with coloured pigments, and is the application of vitreous enamel to pottery; enamelled glass is very similar but on glass. Both these ...