Black Sculpture Clay with Fine Grog. Sold in 27.5lb bags Black sculpture clay body with 40% fine grog (up to 35 Mesh). Formulated for artistic ceramics, it is ideal for sculpture. The high content of grog confers a beautiful textured surface and an excellent behavior during drying and firing. Its beautiful and intense black firing color in oxidizing 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). Recommendations for use with glazes Use zinc-free (Zn-free) glazes to prevent from unexpected reactions such as bubbling or colour 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. Do not use glazes with a low coefficient of thermal expansion (a25-300ºC 60x10-7ºC-1). Firing - Ceramic kiln high fire Weight/Volume - 27.5 lbs - 12.5 kg Grog - Fine grog State - Moist form (plastic body) Stiffness - For wheel throwing and handbuilding Firing range: Cone 5-7 (2192º-2300ºF / 1200-1260ºC) Bisque firing temperature: Cone 06 (1832ºF / 1000ºC) Water content: 21% Plasticity (IP Atterberg): 22 Carbonate content (CaCO3): 0% Drying shrinkage: 7.0% Firing shrinkage at Cone 7: 4.5% Porosity (water absorption) at Cone 7: 9.4% Dry bending strength: 2.0 N/mm2 Fired bending strength at Cone 7: 27.5 N/mm2 Thermal coefficient (a25-500ºC): 55.8x10-7ºC-1
