Drying Pottery Clay

Drying Pottery

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.