The eight firing stages shown on a time/temperature firing graph.
The Goals of a Firing Schedule
Understanding the behavior of glass within different temperature ranges allows you to create a firing schedule or series of steps that will properly heat and cool glass in a kiln. Using a firing schedule, you can accomplish the two basic objectives of kilnforming, which are:
- To bring the glass body to a temperature where it can be formed in the manner or process selected.
- To return the glass to room temperature in a stable condition (i.e., free of unwanted internal stress).
A firing schedule (sometimes called a firing cycle or firing profile) may be subdivided in various ways. At Bullseye, we generally break down the firing schedule into eight stages.
See TechNote 4: Heat & Glass for additional information about each of the firing stages.
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