"QICA" Firing Schedule
Quartz Inversion Cracking Avoider
This schedule slows down around the quartz inversion zone and holds both on the way in and out of each (up and down ramps).
This assumes a large piece that requires slow heatup and cooldown to prevent thermal gradients. If you are firing pieces that are thinner and lighter then steps 2, 4, 6 and 8 could likely be set to a faster rate.
| Step | °C | °F | Hold | Time | |
|---|---|---|---|---|---|
| 1 | 138°C/hr to 121C | 250°F/hr to 250F | 60min | 1:42 | |
| 2 | 111°C/hr to 518C | 200°F/hr to 965F | 30min | 5:46 | |
| 3 | 41°C/hr to 629C | 75°F/hr to 1165F | 30min | 8:56 | |
| 4 | 111°C/hr to 1148C | 200°F/hr to 2100F | 0 | 13:37 | |
| 5 | 55°C/hr to 1204C | 100°F/hr to 2200F | 15min | 14:52 | |
| 6 | 83°C/hr to 629C | 150°F/hr to 1165F | 30min | 22:16 | |
| 7 | 41°C/hr to 518C | 75°F/hr to 965F | 30min | 25:26 | |
| 8 | 83°C/hr to 121C | 150°F/hr to 250F | 30:12 |
Start temperature assumed: 25°C or 75°F
"Fahrenheit degrees" is not the same as "degrees Fahrenheit". A 100° reading on a Fahrenheit thermometer is equal to a 37° reading on a Celcius thermometer. But "100 Fahrenheit degrees of temperature change" is equivalent "55 Celsius degrees of change". That is an important distinction to understand the above temperature conversions.
"Fahrenheit degrees" is not the same as "degrees Fahrenheit". A 100° reading on a Fahrenheit thermometer is equal to a 37° reading on a Celcius thermometer. But "100 Fahrenheit degrees of temperature change" is equivalent "55 Celsius degrees of change". That is an important distinction to understand the above temperature conversions.
Related Information
Links
| Glossary |
Quartz Inversion
In ceramics, this refers to the sudden volume change in crystalline quartz particles experience as they pass up and down a temperature window centering on 573C. |