jolieo

a new challenge right? how about "poetry in motion" or words of wisdom

Hi Alice : are you firing to cone 05 (1915 degrees f) or cone 5 (2185 degrees f)? Potters choice are cone 5/6 glazes...

Underglazes are the color. They are similar to oxides, except oxides are reactive to the chemistry around them, either in the clay or the glaze or both. Underglazes are made non reactive. They are also usually the color they will be albeit not the same intensity. They can be left unglazed, but I think they are just decorative at that point. They probably would be in danger of abrasion or wear. A glaze is almost a glass that is melted on to the ceramic in either it's green ware state or its bisque state.glass has to be compatible in what shrinkage and expansion each glass has .if too far apart , they come apart. Clay and glaze have those same issues, plus other issues to do with the clay body. So glazes don't always work even if They are fired to the same cone . Some clays have fluxes, or chemicals that become fluxes in them and they become self glazing. Wood fired kilns can glaze the vessels in the kiln through a deposit of wood ash on the vessels. Adding salt to kiln (not electric unless made for it, ruins the elements) glazes it too. Since clays and glazes have a lot of the same things in them, clays can almost become glazes if chemicals are introduced . The purpose of bisqueing is so that the ceramic is still able to accept the colorant and the glaze but not be as fragile as greenware. Once the vessel has been fired to the point of maturity ( so it is completely fused on a molecular level) It is all but impossible to put glaze on (. I don't know about oxides or underglaze- perhaps they might take if there was tooth). Glaze would slide off I think. Dealing with clay is chemistry or alchemy or both. I think I might learn a few chants to get thing more on my side. Nah it would probably backfire! Jolie