January 3, 2010
General guidelines for drying pottery:
– Even, slow drying is preferred
– Pottery should be bone dry before attempting any firing. Any presence of moisture will increase the likelehood of cracking.
– hunid air flow is ideal because it adheres to the surface more evenly , especially the recessed areas. This can be achieved by enclosing a section of the studio/plant with plastic to create a humidity chamber, the wet ware creating a naturally humid enviroment. With smalll scale operations, covering the ware racks with cloth or plastic is a viable option.
-Make sure pots are positioned so ther air circulates freely around them.
-Depending on the style of piece being dried ( eg. complex shapes ), the placement , air flow adjustment and covering of fast drying areas with wax, all support eveness of drying.
-it can take several days for ware to dry in a natural enviroment( 2 days for a dessert bowl )
– If you don’t have a +100°C drying chamber, your kiln is the final stage batch drier. The addition of air flow to remove excess moisture could be considered. This can be achieved with a venting system.
– A consant air flow is needed along with tuning the humidity by adjusting the dry air rate in and the humid airflow out. Otherwise , slower drying in a humidity chamber is an acceptable alternative.
– Due to its higher density, you cannot expect porcelain to dry as well as stoneware or earthenware.
-Pots made in one piece may be dried more quickly, but should be turned upside down if possible as soon as they have hardened a bit. If they can’t be turned upside down, set them on a drywall ( sheetrock, gypsum board, wall board ) or plaster to allow their bottoms to dry evenly.
-Handle bone dry pieces carefully as the have a tendancy to crack easily due to their brittleness prior to firing.
– If a piece looks dry but is cool to the touch this sometimes indicates it is still moist and continued evaporation is needed.
Nazla, Egypt — A potter at work in the village of Nazla, an Egyptian village in the Fayyum known for its pottery. — Image