Monthly Tech-Tip | No tracking! No ads! |
This mug is pinging loudly and literally self-destructing in front of my eyes! Why? The glaze is under so much compression (the inside is pushing outward, the outside inward). Spiral cracks are developing all the way up the side. Small razor-sharp flakes are shivering off convex contours. Why? I accidentally fired a low-temperate talc body at cone 6 (the glaze is the Alberta Slip base cone 6 glossy). The clay body is not overly mature, but it just has an extremely high thermal expansion (talc is added to increase the expansion to fit low fire commercial glazes, they would craze without it). Shivering is serious, it is a mismatch of thermal expansion between body and glaze. It can happen at any temperature.
Glossary |
Glaze fit
In ceramics, glaze fit refers to the thermal expansion compatibility between glaze and clay body. When the fit is not good the glaze forms a crack pattern or flakes off on contours. |
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Glossary |
Artware
Potters know artware as pottery firing at low temperatures with brightly coloured glazes and decorated using decals, underglazes, lustres, etc. |
Troubles |
Glaze Shivering
Ask the right questions to analyse the real cause of glaze shivering. Do not just treat the symptoms, the real cause is thermal expansion mismatch with the body. |
Troubles |
Glaze Crazing
Ask the right questions to analyse the real cause of glaze crazing. Do not just treat the symptoms, the real cause is thermal expansion mismatch with the body. |
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