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GlazeDigitalFire Archive

FAC5

Glaze FAC5 is a spodumene-talc based crystalline glaze formulated for a maturing range of cones 6–9, with optimal results typically achieved at cones 8–9. The fired surface features a colorless transp

personBy Tony Hansen

Recipe (Percentages)

zinc-oxide27 %
silica14 %
spodumene4 %
talc4 %
titanium-dioxide1 %

Notes & Instructions

Glaze FAC5 is a spodumene-talc based crystalline glaze formulated for a maturing range of cones 6–9, with optimal results typically achieved at cones 8–9. The fired surface features a colorless transparent ground with abundant white crystals characterized by complex, frilly internal structures resembling hemimorphite. Growth rates for crystals range from 1.0 to 1.5 cm per hour. To achieve optimal crystallization, fire to maturity with a 5-minute peak soak, followed by a 50°C drop and a controlled cooling ramp to 1000°C over approximately 90 minutes. The glaze demonstrates strong seeding properties and is compatible with various colorants; however, note that copper carbonate concentrations below 4% may result in overly transparent crystals due to low titania content. Addition of 3% nickel oxide produces steel-blue crystals on an amber base. Crazing is minimal on vessel forms. The glaze is relatively stable in reduction atmospheres, though colors may appear slightly muted. Ensure consistent application thickness for predictable crystalline development.

Chemical Analysis (UMF)

Si:Al Ratio

32.00

Mapa de Stull (Predicción Visual)
R2O (Fluxes)0.707
RO (Alkaline Earths)0.293
R2O3 (Alumina)0.095
RO2 (Silica)3.031

check_circleForecast

According to its position on the Stull Chart, this glaze has a glossy and stable melt.

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