Shivering on a transparent over an engobe

Tuesday 29th July 2014

Example of a glaze (G1916J) shivering on the rim of a mug. But the situation is not as it might appear. This is a low quartz cone 03 vitreous red body having a lower-than-typical thermal expansion. The white slip (or engobe) has a moderate amount of quartz and is thus put under some compression by the body. But the compression is not enough to shiver off (e.g. at the rim) when by itself. However the covering glaze has an even lower expansion exerting added compression on the slip. This causes a failure at the slip-body interface.

Pages that reference this post in the Digitalfire Reference Database:

Quartz Inversion, Engobe, Shivering, Glaze fit, Glaze Shivering

This post is one of thousands found in the Digitalfire Reference Database. Most are part of a timeline maintained by Tony Hansen. You can search that timeline on the home page of digitalfire.com.