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Fusion Frit FZ-915

Oxide Analysis Formula
SiO2 22.00% 2.86
B2O3 15.50% 1.74
Na2O 4.00% 0.50
K2O 2.50% 0.21
ZnO 3.00% 0.29
Bi2O3 53.00% 0.89
Oxide Weight 781.80
Formula Weight 781.80


This is the only bismuth frit that we know of that is available to potters in North America. Their data sheet gives an approximate analysis of 2-6% K2O, 1-4% Na2O, 2-4% ZnO, 15-20% B2O3, 17-22% SiO2, 50-60% Bi2O3. This was not reconcilable with a data sheet that we had, so numbers from that sheet have been pulled just inside their published boundaries. It is not completely clear whether the chemistry is variable because of production issues or the numbers are getting muddled in trade secret initiatives.

This frit is practical only for very specialized uses. The reason is this costs $30/lb (in 2020). That is $1500 per 50/lb bag and $60,000 for the minimum order of 2000 lbs.

Related Information

Fusion Bismuth Frit FZ -915 fired to cone 6

The pure frit powder was simply melted in this tile.


John Britt's work with a bismuth frit
Typecodes Frit
Oxides Bi2O3 - Bismuth Oxide
Materials Bismuth Subnitrate
Materials Bismuth Oxide

By Tony Hansen

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