|Monthly Tech-Tip |
Alternate Names: Minium, Lead(II,IV) oxide
A powerful low fire flux. Once popular for its ability to produce glazes of very good flow qualities without pinholes or other defects. It also has powerful and vibrant color responses to metallic oxides.
Lead in Ceramic Glazes: What Did We Learn?
The long slow death of lead use in ceramics taught us some lessons. Manufacturers who still use acid tests to determine glaze toxicity risk liability.
|Materials||Lead Bisilicate Frit|
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.
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.
|Oxides||PbO - Lead Oxide|
|Frit Softening Point||880C M|
|Density (Specific Gravity)||9.00|