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*:
• Initial Heating • Bubble Squeeze • Final Heating
• Process Step
• 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.