These 10-gram GBMF test balls were melted at 1850F.
| Ferro | Frit 3134 | Frit 3124 | Frit 3195 | Frit 3110 | Frit 3249 |
|---|---|---|---|---|---|
| MgO | 12.2 | ||||
| CaO | 19.5 | 14.3 | 11.4 | 6.3 | 3.5 |
| Na2O | 10.1 | 6.4 | 5.7 | 15.2 | |
| Al2O3 | 2 | 10 | 12 | 3.7 | 13.3 |
| B2O3 | 22.8 | 13.7 | 22.6 | 2.6 | 28.9 |
| K2O | 0.7 | 2.4 | |||
| SiO2 | 45.6 | 54.9 | 48.3 | 69.8 | 42.1 |
| COE | 9.5 | 8 | 7 | 10 | 4 |
| Si:Al Ratio | 38.7:1 | 9.3:1 | 6.8:1 | 32:1 | 5.4:1 |
| R2O:RO Ratio | 0.3:0.7 | 0.3:0.7 | 0.3:0.7 | 0.7:0.3 | |

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These 10g balls GBMF test balls were fired far lower than typical bisque; notice how many of them are already melting well! Frit 3602 is lead bisilicate. Maybe you always thought lead was the best melter. But it got "smoked" by the Fusion FZ-16 high-zinc, high-boron, zero-alumina frit! However, notice the FZ-16 is crazing badly; that is a problem for many applications using this high KNaO frit. Want to get some of this frit for pottery? You can't; Fusion Ceramics doesn't want to handle retail sales of smaller quantities.
Notice that, at this low temperature, each frit has a distinctive melt fingerprint that makes it recognizable.
Notice that the common North American pottery frits on the bottom row: 3195, 3249, 3124, 3110 (and 3134 in the second row) fire distinctly differently. Notice Fusion F69. It looks like 3249 because it is a substitute for it! F-75 is a substitute for 3110 (sharing the same melting pattern but having different micro-bubble clouding).
| Materials |
Ferro Frit 3124
A commonly available calcium borosilicate frit. It is glaze-like, needing only a kaolin addition to create a low-temperature glossy glaze. |
| Materials |
Ferro Frit 3134
A frit with 23% B2O3. The most common of frits used in pottery in North America. Around the world, other companies make frits of equivalent chemistry. |
| Materials |
Ferro Frit 3195
A commonly available calcium borosilicate frit. It is glaze-like, needing only a kaolin addition to create a low-temperature semi-glossy glaze. |
| Materials |
Ferro Frit 3110
High sodium, high thermal expansion low boron frit. A super-feldspar in clay bodies. Melts at very low temperatures. Useful to make crackle glazes. |
| Materials |
Ferro Frit 3249
A magnesia borosilicate frit. Very low thermal expansion. Invaluable for increasing the MgO in glazes (to prevent crazing and create matteness). Low melting. |
| Glossary |
Chemical Analysis
In ceramics, raw material chemistry is expressed a chemical analyses. This is in contrast to fired glaze chemistries which are expressed as oxide formulas. |
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