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Ferro Frit 3134

Leadless and low alumina high calcia borosilicate frit

Alternate Names: F3134

OxideAnalysisFormula
CaO19.51%0.680
Na2O10.14%0.320
Al2O32.00%0.038
B2O322.79%0.640
SiO245.56%1.483
Oxide Weight195.57
Formula Weight195.57
If this formula is not be unified correctly please contact us.
COLE - Co-efficient of Linear Expansion 9.47
MLRG - Frit Melting Range (C) 1450-1600F

This is a USA pottery frit. Ferro now calls it Frit 3134-2.

This is a popular frit and has been used for many years as a general purpose melter across all tempreatures. Equivalents are made by many frit companies. Ferro says that it is "intended for use as a lime and borate source in partially fritted glazes, lead bisilicate glazes and low cost hobby glazes cone 06-10". But from the viewpoint of ceramic chemistry, this frit is a great 'oxide warehouse', it is useful in so many kinds of glazes, we often use it to showcase the value of Frits in formulating and adjusting glazes as (formulas of oxides rather than recipes of materials).

The reason this is billed as useful in partially fritted glazes is because of how valuable it is in supplying B2O3 (raw B2O3 sources have many issues). It gives us lots of boron about with CaO and Na2O (which most glazes need) but no Al2O3 (so it can be supplied from clay to harden and suspend the slurry).

Several factors make this frit's chemistry so attractive:

-It has almost no alumina. That means, as already stated, that Al2O3 can be supplied by clay, giving the glaze better suspension and hardening properties. Conversely, adding Frit 3134 to a recipe (to supply boron for example) does not require reduction of clay content.
-It has high sodium. That means that it's presence enables reducing feldspar content which in turn provides even more opportunity to source Al2O3 from kaolin or clay.
-It has high boron. That gives it a lot of bang-for-buck as a flux, especially in middle temperature.
-It has a very high CaO content. That makes it useful for developing chrome-tin pinks and maroons. CaO-sourcing raw materials do not normally melt at low temperatures but a frit of this chemistry (high soda and boron) does.

The high expansion of this frit is quite useful since it can be used in a frit blend to create low-temperature glazes with adjustable thermal expansion. The high boron means it can tolerate a very high alumina content from other materials, especially clay. For example, 40 Frit 3124, 40 Frit 3134 and 20 Kaolin is expansion-adjustable since the Frit 3134 can be increased at the expense of 3124 if the glaze is shivering and vice versa if it is crazing.

This frit is often used effectively as part of the strategy to substitute for Gerstley Borate in glazes. It is valuable because it contains lots of sodium and calcium while at the same time sourcing the B2O3. This often enables reducing the feldspar content in the glaze, and then replenishing the oxides contributed by both it and the GB with this frit and kaolin (the latter of which acts to suspend and harden the glaze slurry).

Since Frit 3134 contains no Al2O3, it is not a completely stable glass, it can leach in glaze slurries over time and precipitate. It is often possible to reduce its amount in favor of the more balanced Frit 3124 (where the glaze has significant feldspar). However, if you drive the clay content too low to accomodate the Al2O3-containing Frit 3124 (using ceramic chemistry), you may find the extra hassle of poorer application properties and powdering worth enduring some precipitation issues.

Sub: See also: TAM C-14, General 367-A, 4508


Pictures

How do metal oxides compare in their degrees of melting?

Metallic oxides with 50% Ferro frit 3134 in crucibles at cone 6ox. Chrome and rutile have not melted, copper and cobalt are extremely active melters. Cobalt and copper have crystallized during cooling, manganese has formed an iridescent glass.

GA6-A Alberta Slip base on the insides of two bowls

This has produced a defect free fired surface at cone 6 oxidation on a dark and light burning clay body. To get this type of surface for stoneware bodies it is important to soak the kiln at cone 6, then cool it 100 degrees F and soak it again for half an hour. For coarser clays it is also helpful to program a 200 degree per hour cool all the way down to 1500F.

Low expansion version of cone 6 Alberta Slip amber glaze glaze

Alberta Slip with 20% added frit 3134 (left) fired to cone 6 on a porcelain. This is the standard GA6-A recipe. On the right 20% frit 3249 has been used instead. That is a low expansion frit so if you have crazing with the standard recipe, consider trying this one.

Crystallization of Rutile at cone 6 completely subdued? How?

These glazes are both 80% Alberta Slip, but the one on the right employs 20% Ferro Frit 3249 accelerate the melting (whereas the left one has 20% Frit 3134). Even though Frit 3249 is higher in boron and should melt better, its high MgO stiffens the glaze melt denying the mobility needed for the crystal growth.

Alberta slip cone 6 base (80:20 with frit 3134) plus 4% rutile

Do you know the purpose of these common Ferro frits?

I used a binder to form 10 gram balls and fired them at cone 08 (1700F). Frits melt really well, they do not gas and they have chemistries we cannot get from raw materials (similar ones to these are sold by other manufacturers). These contain boron (B2O3), it is magic, a low expansion super-melter. 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 in bodies and is great to incorporate into glazes that shiver. The high-MgO Frit 3249 has a very-low expansion, it is great for crazing glazes. Frit 3134 is similar to 3124 but without Al2O3. Use it where the glaze does not need more Al2O3 (e.g. it already has enough clay). It is no accident that these are used by potters in North America, they complement each other well. The Gerstley Borate is a natural source of boron (with issues frits do not have).

These two frits have one difference in the chemistry. What?

These two boron frits (Ferro 3124 left, 3134 right) have almost the same chemistry. But there is one difference: The one on the right has no Al2O3, the one on the left has 10%. Alumina plays an important role (as an oxide that builds the glass) in stiffening the melt, giving it body and lowering its thermal expansion, you can see that in the way these flow when melting at 1800F. The frit on the right is invaluable where the glaze needs clay to suspend it (because the clay can supply the Al2O3). The frit on the left is better when the glaze already has plenty of clay, so it supplies the Al2O3. Of course, you need to be able to do the chemistry to figure out how to substitute these for each other because it involves changing the silica and kaolin amounts in the recipe also.

Even highly fritted glazes have to liberate some carbon

Five common North American Ferro Frits fired at 1850F on alumina tiles (each started as a 10 gram ball and flattened during the firing). At this temperature, the differences in the degree of melting are more evident that at 1950F. The degree of melting corresponds mainly to the percentage of B2O3 present. However Frit 3134 is the runaway leader because it contains no Al2O3 to stabilize the melt. Frit 3110 is an exception, it has low boron but very high sodium.

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By Tony Hansen

XML for Import into INSIGHT

<?xml version="1.0" encoding="UTF-8"?> <material name="Ferro Frit 3134" descrip="Leadless and low alumina high calcia borosilicate frit" searchkey="F3134" loi="0.00" casnumber="65997-18-4"> <oxides> <oxide symbol="CaO" name="Calcium Oxide, Calcia" status="U" percent="19.510" tolerance=""/> <oxide symbol="Na2O" name="Sodium Oxide, Soda" status="U" percent="10.140" tolerance=""/> <oxide symbol="Al2O3" name="Aluminum Oxide, Alumina" status="" percent="2.000" tolerance=""/> <oxide symbol="B2O3" name="Boric Oxide" status="" percent="22.790" tolerance=""/> <oxide symbol="SiO2" name="Silicon Dioxide, Silica" status="" percent="45.560" tolerance=""/> </oxides> </material>


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