L3685U
DraftDescription
L3685U is a versatile, plastic white-firing material formulated for use as both a casting/throwing body and an engobe (slip) at Cone 03. It is designed to match the firing shrinkage of low-fire stonew
Original Author
Tony Hansen
Usage Instructions
L3685U is a versatile, plastic white-firing material formulated for use as both a casting/throwing body and an engobe (slip) at Cone 03. It is designed to match the firing shrinkage of low-fire stoneware and terra cotta bodies to ensure structural integrity and adhesion. The formulation utilizes high-plasticity kaolin (e.g., 6Tile) to maintain whiteness and a specific frit-to-kaolin balance to achieve necessary vitrification, which is critical for preventing shivering and promoting a durable bond. As an engobe, it can be pigmented with metal oxides or stains for decorative layering. For optimal performance, the slurry should be gelled to ensure proper application thickness. To prevent micro-bubbling in overglazes, ensure the glaze formulation minimizes gas-producing components like raw kaolin or implement a pre-maturation soak (e.g., 1400°F) to allow off-gassing before the glaze surface seals. Avoid applying vitreous engobes to high-porosity earthenware, as the resulting firing shrinkage mismatch will lead to interface failure. For consistent results, tune the bentonite content to match the specific drying shrinkage of the base clay body.