G2934
DraftDescription
G2934 is a boron-fluxed, MgO-based matte glaze designed for Cone 6 oxidation firing. It provides a durable, silky surface with low thermal expansion and good chemical stability. The glaze is optimized
Original Author
Tony Hansen
Usage Instructions
G2934 is a boron-fluxed, MgO-based matte glaze designed for Cone 6 oxidation firing. It provides a durable, silky surface with low thermal expansion and good chemical stability. The glaze is optimized for dipping and performs well as a functional, non-leaching surface. For optimal suspension and application, the glaze should be thixotropic: target a specific gravity of 1.43–1.44 and introduce thixotropy using Epsom salts (initially 1g per 1000g of dry powder). The slurry should be screened through 80 mesh to remove agglomerates. If using raw kaolin, ensure a portion is calcined to prevent drying shrinkage and crawling; if adjusting proportions, maintain chemical balance by accounting for the 12% weight loss of raw kaolin. Matteness is dependent on cooling rates; fast cooling produces a silky matte, while slow cooling results in a drier, more matte finish. To adjust the surface, blend with G2926B (glossy base) volumetrically. Test all colorant and opacifier additions for potential crawling or pinholing, especially on iron-bearing clay bodies. A drop-and-hold firing schedule is recommended to mitigate gas-related surface defects.