Chestnut Wood Ash, washed (栗灰)
A standard material in Glazecalc's library: its oxide analysis, unity contribution and hazards.
What it is
- Kind
- Fluxes
- Status
- Historical
- Formula
- K₂O 0.4%, MgO 5.6%, CaO 46.9%, Al₂O₃ 2%, SiO₂ 3.9%, P₂O₅ 3.4%, Fe₂O₃ 0.5%, LOI 36.4%
- Also called
- 栗灰, Chestnut ash, kuribai
- Similar materials
- Synthetic Wood Ash (合成土灰)
- Source
- 吉田博和・児玉弘人・郡司恋緒菜・根本達志・新島佐知子「笠間長石と栗剪定枝焼却灰を用いた釉薬に関する研究」, 茨城県産業技術イノベーションセンター研究報告 53 (2024), 表1, 栗灰 E (2024)
Historical, a local ash: chestnut prunings burnt in Kasama, Ibaraki, then washed by soaking in water and changing the water each time it settled. This is one of six samples (sample E, a semi-quantitative XRF analysis). Across the six, CaO ran from 38.6% to 47.1% and SiO₂ from 3.4% to 9.9%, the extra silica from soil picked up with the ash. It is not sold.
Oxide analysis and unity formula
Glazecalc has the analysis of Chestnut Wood Ash, washed (栗灰) as weight percent of the raw material. The unity contribution is the moles of each oxide in the amount of Chestnut Wood Ash, washed (栗灰) that holds 1.0 mole of flux, which is how Glazecalc adds it into a recipe's unity formula.
| Oxide | Weight % | Unity contribution |
|---|---|---|
| K₂O | 0.4 | 0.004 |
| MgO | 5.6 | 0.142 |
| CaO | 46.9 | 0.854 |
| Al₂O₃ | 2 | 0.020 |
| SiO₂ | 3.9 | 0.066 |
| P₂O₅ | 3.4 | 0.024 |
| Fe₂O₃ | 0.5 | 0.003 |
- Equivalent weight
- 102.09
- Fired weight
- 64.93
- Loss on ignition
- 36.4%
The equivalent weight is the grams of Chestnut Wood Ash, washed (栗灰) that hold 1.0 mole of flux. The fired weight is what is left of that after firing.
Hazards and safety
Hazards: Wood ash is caustic, and so is the water it is washed in: wear gloves and eye protection, and avoid breathing the dust.
Use it in a recipe
Add Chestnut Wood Ash, washed (栗灰) to a recipe in the Glazecalc calculator to see what it does to a glaze's unity formula.