Pure Ravenscrag Slip
Recipe
Notes
Ravenscrag Slip is a revolutionary glaze material for stoneware. At cone 10R it can be used pure and produces a functional semi-gloss surface. The possibilities are endless on what you can do by adding things to this base material. You can make additions to gloss it or matte it more, color and variegate it and/or opacify it. Most will contain 90% Ravenscrag (you can make bamboo, tenmoku, celadon, iron crystal, white, matte, glossy, and much more). Ravenscrag Slip is a clay, so it shrinks. We recommend starting a 50:50 raw:roast mix in recipes that call for a high percentage of the material (use the roast instructions at http://ravenscrag.com). Adjust the proportion to get the fastest drying possible while still drying hard and having good slurry suspension. Ravenscrag glazes resist settling in the bucket and go on even (when mixed correctly). Glazes having a high percentage of Ravenscrag Slip are most often prepared using the traditional method of simply adding water until the preferred viscosity is achieved (the material has inherent properties that produce functional slurries for dipping). Control of drying shrinkage and slurry character is achieved by varying the proportion roast and raw powder in the recipe. For us, a weight ratio of 88 water to 100 powder (2200 tap water for 2.5kg of powder) produces a creamy slurry that gives the right thickness on 1-2 second dip on 1850F bisque-ware (with minimal dripping), it has 1.45-1.47-specific-gravity. Using your water you will likely find some variation in this. This recipe actually does not respond to flocculant additions that gel traditional mineral-blend glazes to a thixotropic state. 3000 grams of powder mix makes about 1 Canadian gallon.
Description
Ravenscrag all by itself makes a great cone 10 reduction semi-gloss glaze. It also has great working properties.