Glaze Shivering

As with crazing glaze shivering is also a clay body glaze non-fit event upon cooling. Shivering is most likely to be observed on the edges or ridges of ceramic forms. If one or two pieces in a kiln load show this defect it is always a good practice to hit lightly with a metal object (screwdriver) the remaining pieces to see if shivering can be induced. Some ceramic pieces might look stable but shiver at a later date.

In shivering the fired glaze is under too much compression and begins to buckle or flake off in sheets exposing the underlying clay body. If one glaze shivers adjusting the glaze with a high expansion material such as frit or feldspar will bring the glaze into a compatible fit with the clay body. High expansion materials will actually shrink the glaze to fit the clay body. Depending on which is the predominate flux additions of 5% feldspar or frit in the glaze can often bring about a correction. If many different glazes are shivering additions of 5% to 10% feldspar to the clay body will bring about a correction since the clay body and not the glaze is causing the non-fit situation. Another course of action is to simply use another clay body of the same fired color and temperature range. Statistically shivering glaze/clay body mismatches are rare when compared with the many possible glaze and clay body combinations that do work compatibly.