Leather-hard clay

Childhood, the Teenage Years, Adulthood, and Death What is leather-hard clay ... 

Leather-hard clay is formed when a natural clay piece is allowed to slowly dry to a partially dry state. 

Once a hollow segment is extruded, it can t be bent nor its shape changed,so I have to coax the clay out of the extruder with exactly the curve I want it to have in its final form. The didjibodhran is extruded in four separate segments, which are attached once they have dried to a leather-hard state. The goatskin drum head is then attached using water-soluble glue. 

Leather-hard state The state of a body, typically clay or clay-like, in which it resembles leather in flexibility, stiffness, and ductility. 

Critical Moisture Content. The moisture content of a clay at which the clay particles touch, the water occupies the voids between the particles, and no shrinkage occurs on further drying. It corresponds roughly to the leather-hard (q.v.) state. Drying can be more rapid below the critical moisture content, without risk of distortion. 

The applications of haimner mills are numerous and cover diverse industrial processes. They are capable of grinding almost anything tough fibrous solids such as bark or leather, steel turnings, soft wet pastes, sticky clay, hard rock, and so on. 

---