FIRING (9b) Things to remember in pottery.
Firing – things to remember.
a) Make sure you never fire higher than is permitted for the type of clay you are using. All clay when bought is marked with the firing temperatures. Over fired clay can disintegrate, which means melting and this could destroy your kiln.
b) The normal temperature for firing clay is between 850º C and 1100º C
c) The higher the firing, the stronger the bisque and the better it is for exterior decoration.
d) Clay must be dry for bisque firing. The ware that is not decorated with any type of glaze can touch other pieces; one piece of ware can be put inside another or boxed edge to edge but do not overdo it.
e) Never put decorated bisque and clay together in the same firing. The gases from the clay can affect the colors, making them dull and matte, as though not completely fired.
f) When a design is made up of many pieces and you are mixing decorating techniques and color, all the pieces must be fired at some time to the highest temperature being used, so that they shrink in the same proportion.
a) It can be bisque fired up to 1300º C and then decorated, fired again with colors that vitrify at temperatures up to 1280º or less.
b) It can be bisque fired up to 1000º C and then decorated, fired again with colors that vitrify at temperatures up to 1280º or less and if there are any parts that are not decorated, they must also be fired as the shrinking will continue.