Ash Glazes
Wood and plant ash have been used as glaze flux for thousands of years. The mineral content of the ash (calcium, potassium, silica, phosphorus) varies with the source plant, creating surfaces that are impossible to replicate with refined materials.
Recipe
A 50/50 ash glaze — the simplest starting point. Wash the ash first to remove soluble alkalis.
| Material | % |
|---|---|
| Hardwood ash (washed) | 50 |
| Feldspar (Custer) | 30 |
| Ball clay (OM4) | 20 |
Variations: substitute rice husk ash for hardwood ash for a more matte, white surface. Neem ash produces warmer, golden tones.
Firing
Works at cone 6 through cone 10. Lower temperatures produce drier, more matte surfaces. Higher temperatures give fluid, glossy results with more movement. Can be fired in oxidation or reduction — reduction tends to give warmer, more varied surfaces.
Notes
Every batch of ash is different. Even ash from the same tree species will vary by season, soil, and burn temperature. Always make test tiles with each new batch before committing to finished work.
Ash preparation: soak in water for 48 hours, stir and decant the water (this removes soluble potassium and sodium). Repeat 2–3 times. Dry and sieve to 80 mesh.
Test Tiles
Photos of test tiles will be added here.