"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.

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.

By Tony Hansen
Follow me on

Got a Question?

Buy me a coffee and we can talk