March 2026: We are doing major upgrades to code here, please be patient regarding any issues. If any page is not working for a period of hours, please contact us. Thank you.
| Monthly Tech-Tip | Feb 14-15, 2026 - Major Server Upgrade Done | No tracking! No ads! |
An example of a highly fluid cone 6 glaze that has pooled in the bottom of a mug (and crystallized). Glazes normally need to be under some compression to avoid crazing (by having a lower-than-the-body thermal expansion), but if they are thick like this the body does not have the strength to resist the extra outward pressure the glaze can be exerting at the base from the inside. The result here is a separated base. Conversely, if the glaze is under tension (having too high an expansion), the cracks that develop within it to relieve the tension are deep and wider and thus more likely to propagate into the body. The ultimate result: Poor ware strength and durability. A better solution is to use a liner glaze.
| 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 |
Glaze Compression
In ceramics, glazes are under compression when they have a lower thermal expansion than the body. A little compression strengthens ware, too much can weaken and even fracture it. |
Buy me a coffee and we can talk