Even though the green wares look completely dry, the body might conceal some moisture inside. The beginning of firing should be slow in low heat for several hours. The door should be left ajar and peepholes left open to let the moisture released.
Normally for Bisque Firing, you don't want to go more than 100C/hour below 600C. Depend on the thickness of pieces, large or heavy works should have a longer soaking time between 50C -100C to avoid hidden moisture and air pockets exploded. In these cases, it might need at 1-3 hours or longer on slow speed firing to 100c and additional soaking hours to release moisture. Thinner pieces like slip-casting ware with even thickness can follow the normal firing 100C/hour after completely bone dry. As soon as you reach the 600C, it can go 150C/hour until you reach the mature temperature.
For Glaze Firing(Oxidation), it could maintain 100C/hour until 600C as long as the pieces are already bisques. Then, 150C/hour or full power is on to finish up. Additional soaking 30 min is recommended for glaze development.
|Firing||Bisque (Thin)||Bisque (Thicker)||Glaze|
|Cone 010||Cone 010||Cone 6|
|Ramp||90C/ hour||50C/ hour||100C/ hour|
|Soak||0.5 hour||3 hours or above||-----|
|Ramp||100C/ hour||100C/ hour||150C/ hour|
|Soak||0.5 hour||0.5 hour or above||0.5 hour|
|Lid||Close @300C||Close @300C||-----|
|Segment 3||Target||900C (cone 010)||900C (cone 010)|
|Ramp||150C/ hour||150C/ hour|