G1947U
DraftDescription
G1947U is a high-temperature (Cone 10) transparent base glaze designed for use on porcelain and whiteware bodies. Its formulation utilizes wollastonite as the primary source of CaO to improve surface
Original Author
Tony Hansen
Usage Instructions
G1947U is a high-temperature (Cone 10) transparent base glaze designed for use on porcelain and whiteware bodies. Its formulation utilizes wollastonite as the primary source of CaO to improve surface quality and consistency. The glaze features low feldspar content to minimize thermal expansion and control crazing, with a kaolin content balanced to ensure suspension while preventing drying cracks. It is suitable as a base for color development through the addition of stains, oxides, or opacifiers. When using Grolleg kaolin instead of EPK, the fired surface exhibits enhanced blue-white characteristics, though it may require 0.25–0.5% Veegum or 1% bentonite for optimal suspension. Zinc oxide is included to assist early melting; it should be omitted for fast-firing cycles where delayed melting is required. The glaze is not highly fluid, so additional fluxing may be necessary if refractory colorants are added. Due to the potential for micro-bubble development, the addition of small amounts of zircopax can act as a fining agent to improve surface clarity. Users should perform leach testing if employing encapsulated stains at the upper limits of the firing range. The recipe is stable and widely compatible with standard high-fire reduction schedules.