A fine grained, medium plastic, deep red firing, native material that vitrifies around cone 7. Suitable as a plasticity-neutral ingredient in medium and high temperature red and brown burning bodies.
Redstone is balanced enough that it can be used as-is for many applications requiring deep natural color. Intermediate colors can be created by blending Redstone with Midstone and Palestone. Any mix of the three will make a workable body.
Note that Redstone contains enough soluble materials that are hostile to the deflocculation process that it cannot be used in casting slips.
A typical set of fired bars. We can compare runs, see
Redstone burns to an attractive red at cone 4. By cone 6 it has darkened to a deep red. By cone 8 it is blistering and beginning to expand toward melting. At cone 2 it fires a warm red progressing down to a typical terra cotta color at cone 02-04.
Some customers are using it as a terra cotta material in preference to Redearth because red color development is excellent and it does not have as volatile a response to overfiring. In addition it dries a little better and has less soluble salts.
Redstone is not been fine ground like most industrial minerals. While this offers process properties advantages, it also means that if bodies containing it are fired quickly or with stiff-melt glazes pinholes could occur.
Drying Shrinkage: 6.0-7.0% Dry Strength: n/a Drying Factor: c331 Dry Density: 2.0
Sieve Analysis (Tyler mesh):
+48: 0-0.1% 48-65: 0.2-0.8 65-100: 1.5-3.5 100-150: 3.0-5.0 150-200: 2.0-5.0 200-325: 5.0-9.0
Cone 2: 3.5-4.5% Cone 4: 4.5-5.5 Cone 6: 5.0-6.0 higher Cone 8: 3.5-4.5 (bloating)
Cone 2: 5.0-7.0% Cone 4: 3.5-4.5 Cone 6: 1.5-2.5
BaO 0.4 CaO 0.3 K2O 2.6 MgO 0.9 Na2O 0.1 TiO2 0.7 Al2O3 14.6 P2O5 0.3 SiO2 68.5 Fe2O3 5.1 MnO 0.0 LOI 6.5%
Safety Data SheetClick here for web view.
|Plainsman Clays Ltd.|
702 Wood Street, Medicine Hat, Alberta T1A 1E9
Phone: 403-527-8535 FAX:403-527-7508