|Monthly Tech-Tip |
Alternate Names: Cedar Heights Goldart
Description: Cream Burning Stoneware
Cedar Heights Goldart is a selectively mined (in southern Ohio), plastic stoneware clay that is airfloated to 200 mesh particle size. It offers excellent working properties and has a wide firing range. It is balanced enough to be used alone. It vitrifies to a light buff at cone 10R (the maximum range is not much beyond that).
Goldart has been used for many years in the pottery and ceramic industries as a body ingredient. It appears in many clay body recipes found in textbooks and magazines.
Cedar Heights Bonding is a 50 mesh version of Goldart.
Physical Properties: Cone 06 1 6 8 10
Dry Shrinkage 8.5 8.5 8.6 8.5 8.8
Fired Shrinage 1.1 4.5 6.2 7.0 7.9
Absorption 14.0 8.5 6.4 4.3 1.4
Color White Cream Light Tan Mottled
Contains some sulfur.
Can be used as a substitute for Jordan fireclay.
Goldart (left) compared to Plainsman Midstone (right). Goldart is a buff and vitreous stoneware at cone 10R. These are fired at cone 7, 8, 10 oxidation and 10 reduction (bottom to top). Soluble salts in the Goldart impart a darker coloration to the reduction fired bar). The Midstone has some coarser particles that make larger speckles in reduction.
The most common commercially 200 mesh available raw terra cotta clay in North America. It fires red, has low plasticity and matures a low kiln temperatures.
Clays that are not kaolins, ball clays or bentonites. For example, stoneware clays are mixtures of all of the above plus quartz, feldspar, mica and other minerals. There are also many clays that have high plasticity like bentonite but are much different mineralogically.
|Pyrometric Cone Equivalent||29-31|
|By Tony Hansen|
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