GR10-A
DraftDescription
Ravenscrag Slip functions as a base glaze for Cone 10 reduction firing, producing a functional, silky semi-gloss finish. Due to its high clay content, formulations utilizing a high percentage of Raven
Original Author
Tony Hansen
Usage Instructions
Ravenscrag Slip functions as a base glaze for Cone 10 reduction firing, producing a functional, silky semi-gloss finish. Due to its high clay content, formulations utilizing a high percentage of Ravenscrag Slip should incorporate a blend of raw and roasted (calcined) material to manage drying shrinkage and minimize crawling. Roasting at 1000°F for two hours is sufficient to eliminate plasticity while maintaining particle consistency. When calculating substitutions, account for a 5–12% weight loss during the roasting process. Slurry preparation typically requires a water-to-powder ratio of approximately 88:100 by weight, targeting a specific gravity of 1.45–1.47 for a 1–2 second dip. This material does not respond to traditional thixotropic flocculants. Ravenscrag Slip serves as a versatile base for additives; additions of calcium carbonate or wollastonite (up to 5%) can increase gloss, while talc (10%+) or alumina (5–15%) induce matting. Note that excessive addition of fluxing agents or incomplete alumina dissociation may increase thermal expansion and lead to crazing. Ravenscrag Slip provides superior depth and surface quality when used as a liner glaze on various stoneware bodies, including B-Mix.