CALCULATOR
Annealing Schedule Calculator
Build a cooling schedule from the glass type and the wall thickness.
Inputs
The thickest solid section, not the average wall. The base of a vessel is usually the answer.
0 = a few small pieces, 1 = a shelf of pieces, 2 = a packed kiln.
Cooling through the annealing range. Lower is always safer and never wrong.
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total schedule
- Soak temperature
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- Strain point
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- Soak time
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- Cooling rate
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- Recommended rate
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- Section
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- Ramp up
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- Slow cool
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- Fast cool
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Things this does not account for
- Schedules are conventional workshop starting points, not manufacturer specifications.
- Thickness means the thickest solid section, not the average wall.
- When in doubt, soak longer and cool slower. There is no penalty for a schedule that is too gentle.
How this works
Annealing is the step that decides whether a piece survives, and it is the one beginners rush. The two variables are the soak — long enough for the whole piece to reach the annealing point — and the cooling rate through the annealing range, slow enough that the stress never builds. Thickness drives both, and it drives them linearly and then worse than linearly.
