Calcium Borate Frit (Potterycrafts P2954)
A standard material in Glazecalc's library: its oxide analysis, unity contribution and hazards.
What it is
- Kind
- Frits
- Formula
- SiO₂ 17.9%, B₂O₃ 50.3%, MgO 0.1%, Al₂O₃ 4.9%, K₂O 0.3%, CaO 26.5%
- Also called
- Calcium Borate Frit, CBF, Potterycrafts P2954
- Sold in
- UK
- Similar materials
- Calcium Borate Frit (Potclays 2268) , Gillespie Borate
- Replaces
- Colemanite (theoretical) , Gerstley Borate
- Source
- Potterycrafts 'Calcium Borate Frit' product page
UK fritted calcium borate used in place of colemanite or Gerstley borate (about 50% B2O3, 26.5% CaO). Expansion 6.1 x 10^-6/°C, firing range 1050-1160 °C. In stock at Potterycrafts in October 2026.
Oxide analysis and unity formula
Glazecalc has the analysis of Calcium Borate Frit (Potterycrafts P2954) as weight percent of the raw material. The unity contribution is the moles of each oxide in the amount of Calcium Borate Frit (Potterycrafts P2954) that holds 1.0 mole of flux, which is how Glazecalc adds it into a recipe's unity formula.
| Oxide | Weight % | Unity contribution |
|---|---|---|
| SiO₂ | 17.9 | 0.623 |
| B₂O₃ | 50.3 | 1.511 |
| MgO | 0.1 | 0.005 |
| Al₂O₃ | 4.9 | 0.100 |
| K₂O | 0.3 | 0.007 |
| CaO | 26.5 | 0.988 |
- Equivalent weight
- 209.1
- Fired weight
- 209.1
- Loss on ignition
- 0%
The equivalent weight is the grams of Calcium Borate Frit (Potterycrafts P2954) that hold 1.0 mole of flux. The fired weight is what is left of that after firing.
Hazards and safety
Hazards: Not classified (Potterycrafts SDS P2954); breathing the dust over long periods raises the risk of lung disease.
Use it in a recipe
Add Calcium Borate Frit (Potterycrafts P2954) to a recipe in the Glazecalc calculator to see what it does to a glaze's unity formula.