Category: Glaze > Clear
Created 2017-05-04 18:59:35 by Stacey McDonald
Categories: Glaze > Clear
Firing Temperature: Δ5-6
Atmospheres: Oxidation
Surface Type: Glossy

Doesn't craze.
1. Add 10 - 20% iron plus 2% nickel for rich deep red when fired at cone 6 then refired at cone 06striking glaze can't be too thin.
2. Add 10 - 20% or more fireclay for mottled green tinged.
3. Add 10 - 20% or more talc for very asian quality glaze.
4. add 5 - 10% or more milled or granular rutile for mottled rich effect.
5. Add 10 - 15% zircopax, 1% cobalt carb, 10% manganese carb yeilds light creamy mottled green, try varying the quantities.
6. For mottled purple add 10-18% zircopax, 1% cobalt carb, .5% manganese carb. For celadon blue add .5% cobalt carb and 3% copper carb.

Material Amount Batch Subtotal
Gerstley Borate 48.45
Silica 27.84
EPK 20.62
Alumina Hydrate 3.09
Total: 100

Percentage Analysis

Ingredient Amount SiO2 Al2O3 B2O3 MgO CaO K2O Na2O KNaO P2O5 Fe2O3 TiO2 LOI
Gerstley Borate48.457.170.4912.981.
Alumina Hydrate3.092.021.07
100% no LOI 54.4712.5115.922.111.570.332.392.720.120.430.16

Unity Molecular Formula (UMF)



0.13 Na2O
0.01 K2O
0.69 CaO
0.17 MgO


0.41 Al2O3
0.76 B2O3


3.02 SiO2
0.01 TiO2


0.01 Fe2O3





0.14 : 0.86

SiO2:Al2O3 Chart

Closest 100 neighbors in Glaze > Clear.

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Stull Chart
SiO2:Al2O3 Ratio
SiO2:Al2O3 Ratio 7.39

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09/2016 Note: This is a new feature. If a recipe material is not listed, that material's data has not yet been added. Some materials only have GHS ratings, while others only have HMIS ratings. Warnings differ between systems and countries. Glazy does not take any responsibility for accuracy of linked SDS information. Contact your ceramics supplier for safety information for your specific materials.
Globally Harmonized System (GHS) Hazardous Materials Identification System (HMIS) SDS Link
Material Pictograms Signal Word Hazard Statements Health Flammability Hazard Protection
Gerstley Borate
Silica HarmfulHealth Hazard DANGER From 200-Mesh SDS:
May cause cancer by inhalation.
Causes damage to lungs through prolonged or repeated exposure by inhalation.
* 0 0 E
EPK HarmfulHealth Hazard DANGER EPK Kaolin is a naturally occurring mineral, which may contain amounts of crystalline silica
typically 0.1-1.0%, may cause damage to respiratory system through prolonged or repeated
1 0 0 E
Alumina Hydrate Harmful WARNING Causes serious eye irritation
May cause respiratory irritation