|Monthly Tech-Tip |
Bismuth nitrate is obtained from metallic bismuth and is soluble in acids but insoluble in water. Impurities are arsenic, lead and silver carbonates.
It gives a pearly luster to glazes and glasses, especially in reduction firing (light reduction). It is an ingredient in luster colors. It is a very very strong flux. Bismuth oxide contains 100% of the oxide while this is only 75%.
Using bismuth it is possible to create very low melting glasses (or glazes). But a very high percentage is required. And bismuth is expensive.
Bismuth Trioxide Toxicology
|Materials||Fusion Frit FZ-915|
|Temperatures||Bismuth Subnitrate decomposes (260C-)|
Materials that source Na2O, K2O, Li2O, CaO, MgO and other fluxes but are not feldspars or frits. Remember that materials can be flux sources but also perform many other roles. For example, talc is a flux in high temperature glazes, but a matting agent in low temperatures ones. It can also be a flux, a filler and an expansion increaser in bodies.
Generic materials are those with no brand name. Normally they are theoretical, the chemistry portrays what a specimen would be if it had no contamination. Generic materials are helpful in educational situations where students need to study material theory (later they graduate to dealing with real world materials). They are also helpful where the chemistry of an actual material is not known. Often the accuracy of calculations is sufficient using generic materials.
|Oxides||Bi2O3 - Bismuth Oxide|
|Frit Softening Point||260C D|