Ag2O | AlF3 | As2O3 | As4O6 | Au2O3 | BaF2 | BeO | CaF2 | CdO | CeO2 | CrO3 | Cs2O | Cu2O | CuCO3 | Dy2O3 | Er2O3 | Eu2O3 | F | Fr2O | Free SiO2 | Ga2O3 | GdO3 | GeO2 | HfO2 | HgO | Ho2O3 | In2O3 | IrO2 | KF | KNaO | La2O3 | Lu2O3 | Mn2O3 | MnO2 | MoO3 | N2O5 | NaF | Nb2O5 | Nd2O3 | NiO | OsO2 | P2O5 | Pa2O5 | PbF2 | PdO | PmO3 | PO4 | Pr2O3 | PrO2 | PtO2 | RaO | Rb2O | Re2O7 | RhO3 | RuO2 | Sb2O3 | Sb2O5 | Sc2O3 | Se | SeO2 | Sm2O3 | Ta2O5 | Tb2O3 | Tc2O7 | ThO2 | Tl2O | Tm2O3 | U3O8 | UO2 | WO3 | Y2O3 | Yb2O3 | ZrO
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|COLE - Co-efficient of Linear Expansion||0.331|
|GSPT - Frit Softening Point||707C (From The Oxide Handbook)|
-Together with sodium and lithium oxides, it is classified as one of the Alkaline group. Colored glazes whose flux portion is alkaline-dominated tend to be visually intense, especially if the alumina is low.
-K2O is considered together with sodium, since the two almost always occur together and have very similar properties. When taken together the two are often labeled KNaO. K2O generally promotes higher melt viscosity than Na2O.
-It is an important auxiliary flux in high temperature glazes.
-It is a heavy oxide and in general hosts the brightest colors of all fluxes except for lead. It is usually preferred even to soda for a more brilliant glossy glaze and longer firing range. Very good colored glazes can be made in K2O-PbO-SiO2 dominant formulas.
-Considered a very stable and predictable oxide.
-Like sodium, it has a very high expansion, this tends to contribute to crazing in higher amounts, but not quite as bad as sodium. Thus high alkali glazes almost always craze. If the color depends on this (i.e. copper blue), then it may be necessary to adjust the body to eliminate crazing (since a reduction of the alkalis to reduce crazing will mean a loss of color).
-The alkalis can increase lead solubility.
Glaze Color - Pink
Alkaline glazes with barium and small amounts of Mn can produce pink.
Glaze Color - Tenmoku
Reduction tenmoku black-rust glazes with 8-10% iron work well in high potash glazes.
Glaze Color - Blue
0.5-1.0% iron in potassium reduction glazes may give delicate blue to blue green.
Glaze Color - Copper Red
Copper red reduction glazes are best in formulations with high alkali. The presence of boron can give a more pleasant red.
Glaze Color - Copper Blue
Oxidation copper blues work best in high alkaline, low alumina glazes. Increasing copper to 4-6% will move color toward turquoise.
Glaze Color - Cobalt Blue
Cobalt blues can be very intense in alkali glazes (up to 2% cobalt).
Glaze Color - Violet
Alkaline dominant glazes will produce violet, purple, burgundy, red blue using manganese dioxide to 2%.
Out Bound Links
Cornish Stone, China Stone, Corn Stn, China-stone
K-Feldspar, Orthoclase, K Feldspar, Potassium Feldspar
Potash Calcined, Calcined Potash
Potassium Carbonate, K2CO3, Pearlash
Potassium chloride, KCL, Silvin, Silvine
In Bound Links
Alkalies are the strong base fluxing oxides of Na2O and K2O. Feldspars are by far the most common alkali sourcing materials, thus the term 'alkali feldspars'. However frits are also an excellent source and sometimes the only alternative to meet the chemistry requirements (e.g. low alumina and high N...
An indispensable material in the ceramic industry. Most ceramic bodies employ feldspar as a flux to vitrify them at a lower temperature (the feldspar creates a glaze that glues the more refractory par...
Most common feldspars contain both sodium and potassium. The term K-Feldspar designates one where the K2O/Na2O balance heavily favors K2O.
On the theoretical glaze chemistry level, a flux is an oxide that lowers the melting or softening temperature of a mix of materials. Fluxes are interactors (they often melt poorly on their own but react strongly with high melting materials where Al2O3/SiO2 predominate). There are less than ten commo...
An oxide is a combination of oxygen and another element. There are only about ten common oxides that we need to learn about (most glazes have half that number). CaO (a flux), SiO2 (a glass former) and Al2O3 (an intermediate) are examples of oxides. CaO (calcium oxide or calcia), for example, is cont...