These common Ferro frits have distinct uses in traditional ceramics

I used Veegum to form 10 gram GBMF test balls and fired them at cone 08 (1700F). Frits melt really well, they do have an LOI like raw materials. These contain boron (B₂O₃), it is a low expansion super-melter that raw materials don’t have. Frit 3124 (glossy) and 3195 (silky matte) are balanced-chemistry bases (just add 10-15% kaolin for a cone 04 glaze, or more silica+kaolin to go higher). Consider Frit 3110 a man-made low-Al₂O₃ super feldspar. Its high-sodium makes it high thermal expansion. It works really well in bodies and is great to make glazes that craze. The high-MgO Frit 3249 (made for the abrasives industry) has a very-low expansion, it is great for fixing crazing glazes. Frit 3134 is similar to 3124 but without Al₂O₃. Use it where the glaze does not need more Al₂O₃ (e.g. already has enough clay). It is no accident that these are used by potters in North America, they complement each other well (equivalents are made around the world by others). The Gerstley Borate is a natural source of boron (with issues frits do not have).

Related Pictures

What has this low fire transparent glaze turned blue?

It is made from 85% Ferro Frit 3134, 7.5% kaolin and 7.5% silica. While not obvious from the recipe, one look at the chemistry of this (as displayed when you enter a recipe into your account at insight-live.com) will show very low Al₂O₃. Frit 3134 has almost no Al₂O₃, yet it is an essential component of functional glazes (for durability, resistance to crystallization, stability during firing). The kaolin is the only contributor of Al₂O₃ and there is only a little. A simple fix would be to use Ferro Frit 3124 instead, remove the silica and increase the kaolin to 15.

Substitute Ferro Frit 3134, using glaze chemistry, in three glaze types

Insight-live screen shot, substituting frit 3134

Can't get frit 3134 for glaze recipes? Can you replace it with frit 3124? No, 3124 has five times the amount of Al₂O₃ (the second most important oxide in glazes) and half the amount of B₂O₃ (the main melter). This ten-minute video presents a glaze chemistry approach that is easier to do than you probably think. On three different recipe types, you will learn to source the needed oxides from two other Ferro frits, 3110 (or Fusion F-75) and 3195 (Fusion F-2) and end up with at least 15% kaolin in each (to suspend the slurry). Each requires a unique approach. Two of the calculations produce improved slurry properties and one yields a recipe of significantly lower cost. If you have a recipe that needs this, get an insight-live.com account, enter it there and I can help you do the calculation.

How to choose ceramic materials to source needed oxides

How does one choose which material to source each oxide needed when doing glaze chemistry formula-to-batch? It is easy to overthink this. Insight-live has thousands of materials of which you likely only have a few. By tapping any of the oxide names in the calculation in a recipe panel it becomes evident quickly that it is fairly simple to know which material to source each oxide from. When ZnO is needed it is sourced by zinc oxide, SiO₂ by silica, TiO2 by titanium dioxide, Li₂O by lithium carbonate or spodumene, MgO by talc or dolomite, CaO by whiting or wollastonite, Al₂O₃ by kaolin or ball clay, KNaO by feldspar. The tricky one is B₂O₃, you’ll get that from frits available to you. The frit you use will bring many of the other oxides so their main sources (the other materials just listed) will need adjustment. This being said, the above must be tempered by material cost and by how the solid state and physical properties of materials affect slurry rheology, glaze laydown and drying.

Links

Materials	Ferro Frit 3110 High sodium, high thermal expansion low boron frit. A super-feldspar in clay bodies. Melts a very low temperatures.
Materials	Ferro Frit 3124 A commonly available calcium borosilicate frit.
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 3249 A magnesia borosilicate frit. Very low thermal expansion and melting point. Invaluable in pottery to increase the MgO in glazes and thereby prevent crazing.
Materials	Ferro Frit 3195 A commonly used boron frit, it is a balanced glaze all along at cone 06-02 (with the addition of 10-15% kaolin). Not fully glossy.
Materials	Frit Frits are made by melting mixes of raw materials, quenching the melt in water, grinding the pebbles into a powder. Frits have chemistries raw materials cannot.
Temperatures	Gerstley Borate Melts Suddenly (870-900)
Temperatures	Common frits begin melting (760-)
Oxides	B2O3 - Boric Oxide
Glossary	Boron Frit Most ceramic glazes contain B2O3 as the main melter. This oxide is supplied by great variety of frits, thousands of which are available around the world.
Glossary	Calculated Thermal Expansion The thermal expansion of a glaze can be predicted (relatively) and adjusted using simple glaze chemistry. Body expansion cannot be calculated.
Glossary	Frit Frits are used in ceramic glazes for a wide range of reasons. They are man-made glass powders of controlled chemistry with many advantages over raw materials.
Glossary	Base Glaze Understand your a glaze and learn how to adjust and improve it. Build others from that. We have bases for low, medium and high fire.
Tests	Glaze Melt Fluidity - Ball Test A test where a 10-gram ball of dried glaze is fired on a porcelain tile to study its melt flow, surface character, bubble retention and surface tension.
Recipes	G1916Q - Low Fire Highly-Expansion-Adjustable Transparent An expansion-adjustable cone 04 transparent glaze made using three common Ferro frits (low and high expansion), it produces an easy-to-use slurry.
Troubles	Glaze Shivering Ask the right questions to analyse the real cause of glaze shivering. Do not just treat the symptoms, the real cause is thermal expansion mismatch with the body.
Articles	Where do I start in understanding glazes? Break your addiction to online recipes that don't work or bottled expensive glazes that you could DIY. Learn why glazes fire as they do. Why each material is used. How to create perfect dipping and brushing properties. Even some chemistry.

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