Mastering Cone 6 Glazes

Buy this book if you ever intend to fire another load of cone 6 glazes in an electric kiln. Buy it if you have been firing at cone 6 for years and have all the other books on the subject; this will become your first reference choice. Buy it if you are just starting to fire at cone 6; with this and a copy of Hamer & Hamer's Potter's Dictionary of Materials & Techniques, you won't need another book for years. You might even want to buy it if you fire to some other temperature than cone6, or in reduction.

What makes John Hesselberth and Ron Roy's new text so remarkable is that it is almost entirely new information, based on their original research. The subtitle, 'Improving Durability, Fit and Aesthetics', indicates what their focus is. Never before has a glaze text provided hard data on stability and oxide leaching, with simple do-it-yourself tests as well as information on professional lab testing. No text has ever gone into such detail on the effects of firing and cooling schedules on glazes. This is also one of the new generation of texts to really take into account the benefits of computers in ceramics, in using both glaze calculation and kiln controlling software. And they include the first set of limit formulas in the history of ceramics to be based on scientific testing, rather than on simple observation.

This book would be immensely valuable if the only chapter you read was the one on 'Fitting Glazes to Your Clay Body'. Hesselberth and Roy begin by explaining crazing, dunting and shivering, and show you how to interpret dilatometer test results, which is how they scientifically measure glaze fit. Then they provide you with five test recipes of differing expansion values. One of these recipes should come close to fitting your clay body and methods of working, and they show you how to further adjust your glazes for perfect fit. Also included are a number of glaze recipes, with essential information on how to fire and cool each of them. This firing information is in fact so critical to the glaze performance that the authors ask people not pass the recipes on to people who have not read the book. Incidentally, all the recipes are made with widely available and predictable materials. But you really should, if you want to do anything original with glazes, develop your own recipes, and this book will be an enormous help with that too.

At the end are appendices on recommended materials, Seger unity formula calculation, glaze calculation software programs, glaze testing laboratories and references for leaching data, firing cycles for electric kilns, materials analyses, and limit formulas.

This book is primarily directed at firing to cone 6 in an electric kiln, but much of the information in it would be helpful to potters working at any temperature, or in any atmosphere. The authors even provide some handy rules of thumb for inventing recipes that will stand up to the acidic and alkaline conditions found in food preparation and dishwashers. The writing style throughout is precise, straightforward and easy to understand, even in the most technical chapters. This is a book written by potters (one of whom is also a chemist) for potters. It will become a classic.

• Paperback: 168 pages
• Publisher: 
• ISBN: 0-9730063-0-7