Revealing Glazes

Using the Grid Method

By Ian Currie
Bootstrap Press  
Copyright ã 2000 by Ian Currie
Click here to read the Copyright Curse
All Rights Reserved
First Edition, June 2000
Soft Cover:  ISBN 0 9589275 3 7
Printed in Australia

Every attempt has been make to find the copyright owners of material quoted.  If any original source has not been acknowledged, please notify the author so that it can be noted in future editions.

Published by Bootstrap Press
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The introduction explores the origins of the grid method and presents some really basic glaze theory including a one-minute chemistry course - all that is necessary to understand the method presented in the book.

What is a Glaze?
Ian Currie's Blue-in-the-Face Chemistry Course.  
Raw Materials  
An Approach to Studying Glazes  
Some Standards  
Extending the Range  

1          Gradients and Variables

The use of gradients and variables in glaze research and problem solving is outlined.  The author shows how to design an experiment so as to reveal hidden cause-and-effect principles.  Some basic information on line blending etc. is given.

The Holy Grail  
Isolating Variables  
Line Blends  
Biaxial Blends and Quadraxials  
Blending and Trending - A Puzzle

2          Outline of the Grid Method

This outline refers particularly to the recipe-based standard grid method, the main subject of this book.  Much of it applies also to the Seger-based grid method as outlined in Ian Currie's first book: "Stoneware Glazes - A Systematic Approach".  Click here to read this chapter in full.

The Standard Grid  
Starting Point  
Varying Alumina and Silica  
The Standard Recipe Grid  
Working out the Flux Material Breakup  
One Glaze Recipe Explains the Whole Set  
Colourants and Opacifiers in the Standard Grid  
Revealing Glaze Principles

3          Choosing a Starting Point

This method shows how to design your own experiment to explore new and exciting areas.  This chapter provides a number of methods for designing a set of glazes.  Click here to see a sample.

Example Sets  
Glaze C Recipes  
Rules of Thumb for Choosing a Flux Set  
Broad Principles  
Table - List of Flux Materials  
Advanced Principles  
Divine Joke  
Family Set  
To get Glaze C:  
Developing the Set Further  
Random Choice

4          Working out the 35 Glaze Recipes

The individual recipes for the 35-glaze grid are easily obtained from the book or from the Calculations Page at this web site. Click here to see a sample.

1.  Using the Calculations Page at the web site  
2.  Using the Flux Breakup Tables  
The Recipe Table  
3.  Using the Recipe Grid Diagram  
4.  Glaze Calculation Software  

5.  Guided Tour - Colour Plates

For anyone wishing to understand how glazes work, this is the core of the book.  Dozens of high quality colour photographs show the different glaze types and show how they are related.  Many important glaze principles are illustrated here.  Also shown are a number of ways the grid method directs one towards the desired result and better understanding.

1.    Isolating Variables  
2.    Standard Limestone Set (The 0.7 Limestone Set)  
3.    Corner A Glazes - High Alumina  
4.    Corner B Glazes - High Alumina and High Silica  
5.    Corner C Glazes - High Flux  
6.    Corner D Glazes - High Silica  
7.    Magnesia Glazes, Strontium Glazes  
8.    Barium Glazes, Zinc Glazes  
9.    Feldspathic Glazes
10.  Alkaline Glazes  
11.  Volumetric Addition  
12.  Clay Body and Firing  
13.  Using the Grid  
14.  Family Set  
15.  Exploring the Limits  

6  Preparing, Firing and Assessing a Grid Set

This is the detailed experimental procedure to use in preparing, firing and assessing a grid set of glazes.

Glaze Preparation - Volumetric Blending  
300 gram Batch Recipes  
Preparing the Four Glazes  
Blending to Produce the 35 Glazes  
Precautions in the Preparation Stage  
Applying the Glazes to the Grid Tiles  
Adjusting Water Content  
Glaze Application  
Applying Colouring Oxides (Optional)  
Firing the Grid Tiles  
Firing Type  
Virtually Identical Firing Conditions  
Bring out the Differences  
Assessing the Results  
Assessing Glaze Fluidity from the Grid Tiles  
Dealing with Runny Glazes  
The Next Step  
Unusable or Dangerous Glazes

7  Volumetric Addition to a Set

This chapter details how the volumetric measuring technique can be extended to gain more in-depth understanding of glazes with minimal work.

A new set of glazes with very little effort  
Addition Procedure

8  Using the Grid Method with Natural Materials

The recipe-based grid method outlined in this book actually arose from a consideration of how to use the grid method with materials whose composition or chemical formula is unknown.  Here we see how to introduce unanalysed materials like wood ashes and powdered rock materials into a grid set. Click here to see a sample.

Flux Material  
Wood Ashes  
Rock and Mineral Materials 
Alumina Sources  
Alumina etc.  
Silica Sources  
Quartz, Silica, Flint  
Using Natural Materials in Glaze C  


Appendix 1        Equipment and Materials  
List of Equipment and Materials  
Glaze Materials  
Making Grid Tiles

Appendix 2        Safety and Health

My First Glaze - A cautionary tale  
Legal Obligations  
Hazards from Raw Materials  
Non-poisonous Materials  
Utilitarian Risk  
Occupational Health and Safety Resources  

Appendix 3         Useful Maths and Chemistry

Reading a Chemical Formula  
Some Raw Materials  
Three Ways to Look at a Glaze  
Oxide Weight %  
Seger Formula  
Comparing Recipe and Seger Formula for 3 Standard Recipe Grids  
Reformulating Glazes  
Chemically Identical Glazes from Different Materials  

Essential Maths  
Percentage Calculation  
Ratios and Proportions  
Volumetric Addition to a Set  
Loss on Ignition - Calcining Calculations  
Calculating L.O.I.  
Calcining Calculations  
The Standard Grid  

Appendix 4  The Recipe Table and Flux Breakup Tables

1.  The Recipe Table  
2.  Flux Breakup Tables