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do you need to slow down firings at quartz inversion temp for alre=

updated tue 13 sep 11

 

DJ Brewer on sun 11 sep 11

ady bisqued pieces?

Once a piece is bisqued, do you need to slow down the firing ramp at
quartz inversion? I always slow down my firings from around 950 to 1250
to between 75 to 100 degrees an hour, then pick it up to 250 to 300 an
hour til I reach 200 degrees less than the target cone, then slow it
down to 100 degrees an hour til it reaches cone.

I follow that basic guideline for both greenware and bisqueware. Is it
an unnecessary slowdown for already bisqued pieces?

Advice and info? (are my quartz inversion temps off? I'm just following
what I learned from my ceramics professor)

DJ

ivor and olive lewis on mon 12 sep 11

ady bisqued pieces?

Dear DJ Brewer,
Have faith in your Ceramics Professor ? Provided your teacher was using th=
e
F scale then range you give seem to be OK.
The important thing is, were you taught how to recognise the difference
between a Dunt that happens when you are refiring your bisque ware to
vitrification and a Dunt that happens when residual Quartz in the vitrified
body changes phase during cooling.
Regards,
Ivor Lewis,
REDHILL,
South Australia