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| Monthly Tech-Tip | No tracking! No ads! No paywall! |
The unglazed surface of the left piece has a sheen, it is a product of glass development during firing to cone 6. That body is a 50:50 mix of a cone 8 stoneware and a low fire earthenware red (a material that would normally be melted by this temperature). Together they produce this dense, almost zero-porosity ceramic. The unglazed surface on the right looks more like plaster, and it is absorbent, about 5% porosity. It is a mix of the same stoneware but with 50% ball clay. The refractory ball clay assures that the stoneware, which was already inadequately vitreous, is even more so. As you can imagine, the left piece is far stronger.
| Glossary |
Fired Strength
Ceramics, by their brittle nature, have high compressive strength and unsurpassed surface hardness. Maximum fired strength can come at the expense of various working and fired properties, so testing is needed to reach a balance. |
| Glossary |
Restaurant Ware
If you are a potter and want to make restaurant ware, read this. Many of the things you already think you know will mislead you in this type of venture. |
| Glossary |
Maturity
A term used in the ceramics industry to signify the degree of vitrification in a fired clay. Mature clays are dense and strong, immature ones porous and weak. |
| Glossary |
Vitrification
A process that happens in a kiln, the heat and atmosphere mature and develop the clay body until it reaches a density sufficient to impart the level of strength and durability required for the intended purpose. Most often this state is reached near zero p |
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