Black Sculpture Clay (PRNG) 12.5kg

Black sculpture clay with 40% very coarse grog 1-3 mm (from 18 to 7 Mesh). Formulated for artistic ceramics, it is ideal for extra large sculptural work and for pieces with high artistic expression. The big content of grog confers an interesting high rugged texture and an excellent behaviour during drying and firing. Its beautiful and intense black firing colour in oxidising atmosphere is very exclusive of PRN range and becomes an ideal artistic mean of expression. In reducing atmosphere, metallic effects with shades of blue are obtained. Available in extruded body (moist form).

Firing range*: 1200-1260ºC/ Cone 5-7
Biscuit temperature: 1000ºC
Water content: 21%
Plasticity (IP Atterberg): 19
Carbonate content (CaCO3): 0%
Drying shrinkage: 7.6%
Firing shrinkage 1260ºC: 2.5%
Porosity (water absorption) 1260ºC: 9.3%
Dry bending strength: 2.7 N/mm2
Fired bending strength 1260ºC: 13.4 N/mm2
Thermal coefficient 1260ºC (25-500ºC): 51.1x10^-7ºC^-1

Recommendations for use with glazes
Use zinc-free (Zn-free) glazes to prevent from unexpected reactions such as bubbling or color changes. Other elements that can react are zirconium (Zr) and tin (Sn). We recommend consulting your usual glaze supplier to ensure proper suitability with this ceramic clay body.

(*) Firing range recommended for the clay to develop its best performance, both in terms of technical and safety characteristics, under conventional firing conditions. The colour samples may show temperatures outside the recommended range to provide a broader view, but these are pieces fired under controlled conditions. Cone equivalence according to Orton table for self-supporting cones, regular-SSB and 150ºC/hr heating rate.