TWVA Ball Clay
A standard material in Glazecalc's library: its oxide analysis, unity contribution and hazards.
What it is
- Kind
- Clays
- Formula
- SiO₂ 52%, TiO₂ 1.1%, Al₂O₃ 31.5%, Fe₂O₃ 1%, CaO 0.2%, MgO 0.4%, K₂O 2.3%, Na₂O 0.3%, LOI 12.9%
- Also called
- TWVA, Potclays 34061
- Sold in
- UK
- Source
- Potclays 'Ball Clay TWVA' product page, ball clay comparison chart ('Information correct Apr 17') (2017-04)
Blend of medium-plasticity white-firing ball clays. Potclays sells it as the replacement for ESVA ball clay, which the producers phased out.
Oxide analysis and unity formula
Glazecalc has the analysis of TWVA Ball Clay as weight percent of the raw material. The unity contribution is the moles of each oxide in the amount of TWVA Ball Clay that holds 1.0 mole of flux, which is how Glazecalc adds it into a recipe's unity formula.
| Oxide | Weight % | Unity contribution |
|---|---|---|
| SiO₂ | 52 | 20.245 |
| TiO₂ | 1.1 | 0.322 |
| Al₂O₃ | 31.5 | 7.227 |
| Fe₂O₃ | 1 | 0.146 |
| CaO | 0.2 | 0.083 |
| MgO | 0.4 | 0.232 |
| K₂O | 2.3 | 0.571 |
| Na₂O | 0.3 | 0.113 |
- Equivalent weight
- 2339.24
- Fired weight
- 2037.48
- Loss on ignition
- 12.9%
The equivalent weight is the grams of TWVA Ball Clay that hold 1.0 mole of flux. The fired weight is what is left of that after firing.
Hazards and safety
Hazards: Fine dust contains respirable crystalline silica; avoid breathing it.
Use it in a recipe
Add TWVA Ball Clay to a recipe in the Glazecalc calculator to see what it does to a glaze's unity formula.