Mastering Cone 6 Glazes: Improving Durability, Fit and Aesthetics

by John Hesselberth, Ron Roy

Overview

The Essential Guide to Mastering Glazing

Professional craftsmen John Hesselberth and Ron Roy present this invaluable resource for potters working with cone 6 glazes. Compared to the more traditional cone 9 method, the relatively lower firing temperature of cone 6 (2,232°F) results in faster kiln heating and cooling times, and the availability of a more diverse color palette for artists to work with. The different temperature range requires compatible glazes. Beyond that, Mastering Cone 6 Glazes provides a wealth of information for all potters, firing at a variety of temperatures, especially on the subjects of durability and cooling.
We at Echo Point Books learned about this book from a veteran professional potter, who urged us to bring it back into print. We’ve since learned that Mastering Cone 6 Glazes is simply the best book on the topic. It describes all of the elements integral in the cone 6 process in clear, easy-to-understand language. The book begins with a thorough and accessible examination of glaze theory, and features detailed discussions about glaze durability and fit, strength testing, shivering and crazing, and color leaching and fading. It also includes detailed recipes for a wide variety of highly effective and aesthetically appealing glazes.
Readers need not be masters of ceramic science themselves; expert authors Hesselberth and Roy present the relevant chemistry and technical material in accessible terms. They help you understand the fundamentals of the process, enough so that eventually you’ll even be able to formulate your own glazes. They also emphasize safety, both in the studio and for users of the pottery, always with an eye on form and function. Mastering Cone 6 Glazes is an essential resource for do-it-yourself artists of all ages and experience levels.

Product Details

ISBN-13:	9781635618853
Publisher:	Echo Point Books & Media, LLC
Publication date:	01/08/2020
Edition description:	Reprint ed.
Pages:	170
Sales rank:	168,972
Product dimensions:	8.00(w) x 10.00(h) x 0.44(d)

About the Author

John Hesselberth is a retired chemical engineer who first had a 30-year career in industrial research. His pottery experience goes back about 25 years when he learned to throw after having built a kickwheel for his wife, Judy. Pottery remained a hobby until he retired from industry in 1996 and he has been building his pottery skills full time since then. He is a juried member of the Pennsylvania Guild of Craftsmen and he has authored articles for both Clay Times and Ceramics Monthly.

Ron Roy has been a studio potter since 1963. His work is shown in many publications, including Robin Hopper's revision of Danial Rhodes' Clay and Glazes for the Potter and The Ceramic Spectrum, Richard Zakin's Ceramics-Ways of Creation, and Karen Ann Wood's Tableware in Clay.

Table of Contents

FOREWORD

PREFACE

ACKNOWLEDGMENTS

A NOTE ABOUT SAFETY

1 INTRODUCTION

Why This Book Is Needed

What Do We Mean by Stable or Durable Glazes? IsThat Different from “Food Safe” Glazes?

The Seger Unity Formula and Its Relevance to Our Work.

2 BASICS OF GLAZING AND FIRING

Safety First

Purchase and Storage of Glaze Chemicals

Weighing and Mixing

Glaze Suspension (Flocculents and Deflocculents)

Bisque Preparation ...........

Bisque Firing

Cleaning

Glaze Resists

Applying Glazes

Firing.....

Loading

Rate of Firing and Cooling

3 TESTING GLAZES FOR STABILITY AND FIT

Testing for Resistance to Acids

In-Studio Testing

Quantitative Testing by a Professional Testing Laboratory

Interpretation of Results

4 MAKING A STABLE GLAZE

Rule 1. Have Enough Silica

Rule 2. Have Enough Alumina

Rule 3. Thoroughly Melt the Glaze

Rule 4. Use Moderate Levels of Colorants and Opacifiers

Guidelines for Improving Glaze Stability

5 FITTING GLAZES TO YOUR CLAY BODY

Understanding Crazing, Dunting and Shivering

Crazing

Shivering or Dunting

Determining Clay/Glaze Fit for Your Materials

Understanding Dilatometer Measurements

Expansion Test Glazes and How to Use Them

Interpreting Calculated and Measured Expansion Numbers

Are Calculated Expansion Numbers Useful?

Expansion Test Glazes

Summary ....

6 STONEWARE AND PORCELAIN GLAZES

Base Glazes

High Calcium Matte/Semimatte Glazes

General Purpose Glossy Base Glazes

Glossy Base Glaze 2

A Clear, Glossy Liner Glaze

A Zinc Semimatte/Glossy Base Glaze

Specialty Glazes

7 DEVELOPING YOUR OWN GLAZES

Glossy versus Matte

Level ofTransparency/Opacity

Solid Color versus Variegated Glazes

Ron’s Approach to Glaze Development

Johns Approach to Glaze Development

Summary

Bibliography

Glossary

Postscript

Appendices

A' RECOMMENDED MATERIALS

B THE SEGER UNITY FORMULA

C PROGRAMS FOR GLAZE CALCULATION

D TESTING LABORATORIES FOR GLAZES

E FIRING CYCLES FOR ELECTRIC KILNS

F MATERIALS ANALYSES

G GLAZES USED FOR DEVELOPMENT OF RULES..

H USEFUL REFERENCES FOR LEACHING DATA

I LIMIT FORMULAS FOR CONE 6 GLAZES

Index

Editorial Reviews

Serious potters will welcome Hesselberth and Roy's approach to the complexities of formulating one's own glazes. They cover the durability of glazes, the leaching of unwanted chemicals into food or drink, the fading of colors, and more.

—Library Journal

From the Publisher