Zero3 L Low Expansion Variant

Code: G2931L
Modification Date: 2018-12-06 09:32:46

Ferro Frit 319519.0
Ferro Frit 324919.0
Fusion Frit F-52449.0
Zinc Oxide2.5


This is a low-expansion version of the Zero3 Clear glaze (code G2931K), originally developed from the Worthington Clear Gerstley Borate based recipe. While G2931K fits the vitreous Zero3 porcelain and non-vitreous bodies containing talc (like Plainsman L212, L215), it crazes on others (e.g. Plainsman TerraStone, BuffStone, L210). This version drops its expansion drastically, from 7.4 down to 6.3 (by adding ZnO, ZrO and increasing MgO and SiO2).

Since the thermal expansion of this is higher than the original Wothington Clear and the L version is lower, it is thus possible adjust thermal expansion of either recipe by adding some of the other (to deal with shivering or crazing on almost any low fire body).

Do not try to use this with too little water. Mix it to 1.43 specific gravity and add vinegar or Epsom salts to gel it so that it stops moving (after vigorous stirring) in 2 or 3 seconds. When mixed right it applies very well to low or high porosity bisque (in a very thin layer if needed), it does not drip or move.

The soak:soak:slowdrop firing schedule is critical to a defect-free surface.

Out Bound Links

In Bound Links

XML to Paste Into Insight

<?xml version="1.0"?>
<recipes version="1.0" encoding="UTF-8">
<recipe name="Low Expansion Low-Fire Clear" keywords="A cone 04-02 clear glaze developed from Worthington Clear. The latter was based on Gerstley Borate, this one employs Ulexite as the melter an is easier to use." id="127" date="2019-04-18" codenum="G2931L">
<recipeline material="Ferro Frit 3195" amount="19.000" unitabbr="KG" added="0"/>
<recipeline material="EPK" amount="10.000" unitabbr="KG" added="0"/>
<recipeline material="Ferro Frit 3249" amount="19.000" unitabbr="KG" added="0"/>
<recipeline material="Fusion Frit F-524" amount="49.000" unitabbr="KG" added="0"/>
<recipeline material="Zinc Oxide" amount="2.500" unitabbr="KG" added="0"/>
<url url="" descrip="Recipe page at"/>

By Tony Hansen

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