G1214Z1
DraftDescription
G1214Z1 is a cone 6 calcia-based matte glaze designed for high melt fluidity. Its chemistry promotes a fine-grained crystalline surface during the cooling phase. To mitigate drying shrinkage and preve
Original Author
Tony Hansen
Usage Instructions
G1214Z1 is a cone 6 calcia-based matte glaze designed for high melt fluidity. Its chemistry promotes a fine-grained crystalline surface during the cooling phase. To mitigate drying shrinkage and prevent crawling, the recipe uses a blend of raw and calcined kaolin. If pre-calcined kaolin is unavailable, it can be prepared by roasting raw kaolin during a bisque firing. For optimal application, maintain a specific gravity of 1.45 using a 2600:3000 water-to-powder ratio; the slurry is naturally thixotropic and generally does not require flocculants. Application should be uniform to prevent drips, as the high melt fluidity can cause running if applied too heavily. The glaze is compatible with various opacifiers and stains, though performance varies: zircon-based opacifiers (e.g., Zircopax) may increase risk of cutlery marking, tin oxide provides superior whiteness, and titanium dioxide creates reactive, rutile-like effects that are sensitive to cooling rates. When using metallic colorants or pigments, leaching tests (such as the GLLE test) are mandatory to ensure food safety, as chemical adjustments to silica and alumina ratios may be necessary to balance durability against the desired degree of matteness. For best results, use a blender to ensure thorough mixing of colorants and to break up agglomerates.