Firing schedules

[Stephen Richard]

Firiing schedules relate to things like thickness, purpose, size, work to be done, glass used, and a host of other variables.

Full speed to top temperature is not usually a good idea, even if you are firing jewellery scale items.  You don’t say what glass you are using, but 810C is a bit high for some glasses.

Each time you fire glass it must be annealed.  Each glass has different annealing soak points and annealing speeds.

I don’t know your kiln from a model number.  Giving the specifications of the kiln is a good idea when asking for advice.  I suggest that 220C/hr is fast enough for the initial heating to 650C range where a bubble squeeze is useful, then ca 330C/hr to 804 for 10 mins for Bullseye.  Cool as rapidly as possible to ca 516C and soak there for ca 30mins, begin the anneal cool at 80C/hr to 370C, no soak, followed by the final cool at ca 200C/hr to ca. 50C.

Of course, this may vary from kiln to kiln and glass to glass.  Get a good introductory book, like Brad Walker’s “Contemporary Warm Glass” to guide you through the initial stages.

Stephen Richard

blogs at: http://www.verrier-glass.blogspot.com/   and  http://www.glasstips.blogspot.com/