- A very commonly
used flux at temperatures over C.4 - 1100 deg.C
- OK to use
in small amounts for temperatures below C.4
- Has moderate
coefficient of expansion and high surface tension.
- Adds whiteness,
hardness and durability.
amounts cause crystal growth through devitrification (lime matts).
- Most commonly
whiting CaCO3 (limestone, calcite).
CaF2 - in limited quantities at lower temperatures
(releases poisonous fluorine).
CaMg(CO3)2 - also
brings MgO (usually primarily a source of MgO).
CaSiO2 - also brings SiO2.
Gives a good glaze at higher temperatures. Can be used to avoid
problems associated with the release of CO2
Gerstley Borate, Calcium Borate Fritt - these are usually used
as a source of B2O3
- Bone ash
- usually used as a source of P2O5.
- Tends to
give alkaline effects with small amounts of colourants (copper
blues, cobalt mauves).
- Can bleach
red iron oxide causing yellowish colourations.
- An excellent
flux for reduced iron glazes - not suitable for oxidised tenmokus.