Terms Flashcards
The first firing a pot undergoes to prepare it for glazing
BISQUE
Air dried clay that how not been fired that is completely dry to touch. Clay is highly fragile at this stage
BONE DRY
AL2O3 2SiO2 2H2O
decomposition of granite creates clay.
____ is a mineral with a plate (platelet) like structure; it is these plates that when lubricated with water, slide against each other to form the plastic mass we know as _____.
CLAY
“____” clays are those found close to the area of Kaolinizationan hence the purest (Kaolin or China Clays).
PRIMARY CLAYS
“____” clays are those moved by water away from the site of Kaolinization and get progressively more plastic and less pure (Ball clays, Fire clays, Earthenwares and Marls)
SECONDARY CLAYS
A clay designed for a special purpose. It is created by blending different clays or by adding to clays other materials, such as feldspar and silica in order to produce a desired workability, maturing temperature or finished result.
CLAY BODY
a method of hand building a form using long rolled out or extruded snake-like lengths.
COILING
Pyrometric _____ are composed of clay and glaze material, designed to melt and bend at specific temperatures. _____ are placed inside the kiln in front of a small peep hold in order to observe the correct temperature in the kiln.
CONES
A type of kiln in which the hot gases, after rising upwards on entering the chamber, are drawn downwards through the ware before escaping through and opening at the bottom of the kiln.
DOWNDRAFT
The process in which clay converts to ceramic. It involves heat of at least 1100 degrees F at which the chemically bonded water in clay is driven off to be changed into stone-like material. The clay can no longer be recycled after the ______.
FIRING
A substance, which causes or promotes melting
FLUX
____ is clay that has not been fired.
GREENWARE
Ground up clay that provides texture, opens the clay body to help in uniform drying and cuts down shrinkage in clay bodies.
GROG
A glass layer or coating that fuses to a clay/ceramic piece during firing. _____ are mixed up of carious minerals, oxides and other additives into a slurry that is applied to bisqueware or greenware in a number of ways.
GLAZE
All glazes must contain:
glass-forming component (silica), a fluxing componentt to help the glaze melt at certain temperature, and a stiffener (alumina) to help keep the glaze from running off the pot.
May also contain colorants and opacifiers
An insulated box heated to fire ceramic ware
KILN
A stage in the drying process when clay is pliable but strong enough to hold a shape and/or bend slightly without cracking. still damp enough to be joined to other pieces of clay with slip. IT is an ideal state for trimming pots or carving
LEATHER HARD
A firing where there is no combustion occurring. This type of firing usually occurs in an electric kiln.
OXIDATION
A method of forming clay be gently squeezing it between your thumb and fingers.
PINCHING
A low temperature firing technique invented by the 16th century Japanese potters. Evolved into a firing process where red hot pieces are pulled from the kiln and placed in a lidded bin filled with shredded newspaper or sawdust. The glazes are dramatically altered by the reduction atmosphere in the lidded bins.
RAKU
A situation where more fuel is introduced into the kiln that it is able burn with the available oxygen, or oxygen is limited (reduced, due to this deficiency, the flame pulls oxygen molecules out of the clay bodies and glazes, changing their character.
REDUCTION
A flattened piece of clay used to build ceramic forms
SLAB
A fluid suspension of clay and warer
SLIP
