Key Chemical Changes in the Firing
0-100C: moisture escape
Caution: ware must be fired slowly tp allow the moisture to escape from the pots completely.
(door ajar, peephole open, pre-soak regarding the thickness of works. I tried cone 6 red clay with fine grog, artwork thickness between 1- 3cmm, pre-soak takes 4 hours.)
100-300C: chemical water and gases start to leave the body; organic matters burn out.
Caution: ware easily explodes during this period if moisture still traps inside the pots.
(all moisture left from the ware around 200C, door, and peephole is closed).
500-600C: silica inversion, crystals from clay to ceramics, shrinkage/expansion 3% begin at 575c (should be fired slowly or soaked for 1/2 hours)
Caution: ware easy to crack if silica inversion goes too fast.
1100-1650C: needlelike glass formation depends on the clay types, go slowly, longer soaking might need for some special glaze.
Caution: pinholes, glaze surface insufficient might appear if soak at the end does not do correctly or smoothly.