This clay was slurried in a mixer and then poured onto a plaster table for dewatering. During throwing it is splitting when stretched and peeling when cutting the base. Yet when this same clay is water-mixed and pugged in a vacuum de-airing pugmill it performs well. One might think that the slurry mixer would wet all the particle surfaces better than a pugmill, but it appears the energy that the latter is putting into the mix is needed to develop the plasticity when there is a high talc percentage in the recipe.
Plasticity (in ceramics) is a property exhibited by soft clay. Force exerted effects a change in shape and the clay exhibits no tendency to return to the old shape. Elasticity is the opposite.
The practice of removing air from clay as it is pugged. Deaired clay has better forming properties and produces a smoother fired surface.