Overview

With the exception of firing schedules for casting, which are outside the scope of this article, glass fusing schedules can be broken down into these seven phases*:

Heating Phases:

•    Initial Heating            •    Bubble Squeeze             •    Final Heating

Change Phase:

•    Process Step

Cooling Phases

•    Rapid Cooling            •    Annealing            •    Final Cooling

Mastering firing schedules requires no more than a good understanding of what each phase does so that you can adjust it to accommodate your specific needs.

With that in mind, let’s warm things up!

* For the purposes of this article, a “phase” is a part of a firing schedule that has a singular purpose.  A “segment” is a single cooling or heating step, plus any temperature hold.  These are the steps we program into our kilns.  As you will see in this article, a single phase might require multiple segments or just part of a segment.