BC1 Ball clay is a very fine grained sedimentary clay powder commonly used to improve clay formulation plasticity. Clay plasticity is an essential in hand building sculptures, clay throwing and even in slip casting. This improves workability due to its fine smooth texture and binding properties. It also a suspending agent in glaze formulation that prevents particles sedimentation and hardening as hardpan. Hardpan can be reconstituted into glaze slurry with addition of measured doses of glaze flocculant. BC1 on its own as a slurry will have a high shrinkage and drying cracks. It cannot be used as a clay body unless with silica, feldspar, kaolin and even grog. Even then clay shrinkages from greenware to fired state can vary from 10 to 15 % due to it fineness. Overall drying time is slower with addition of BC1 ball clay that reduces warping and shrinkage cracks.
It is also used in paint formulation as a pigment extender, opacifier, rheology modifier. suspension aid and binder in water base emulsion paints.
