Jeff Zamek: “What Every Potter Should Know,” Krause Publications, Iola, WI, 1999.
Reviewed by Charles Moore of Sacramento, California, USA
This is a very odd book, and I like it a lot. I should, however, note that the text is structured like a ramble through the vast storehouse of Zamek’s knowledge gained over many years as a potter. Zamek calls the book “a critical mass of bits and pieces of sometimes unrelated information to help solve common problems faced when working with clay” (p. 6). The book’s random structure is not surprising: portions of six of the chapters were previously published in Ceramics Monthly. The chapters need to be read as discrete units, each focused on a particular problem or question.
Zamek has earned right to write about these “bits and pieces” from 30 years of making pots, teaching, and serving now as ceramics consultant. To understand Zamek’s purpose in writing here we need to know that he is, first and foremost, a problem solver.
The book is divided into five “parts,” each part then divided into several chapters. Sometimes there is a clear connection from one chapter to the next; at other times, the selection seems rather random. In short, Zamek’s book is not Hamer and Hamer’s “The Potter’s Dictionary,” neatly arranged in alphabetical order. The fact that a number of the chapters were published separately in Ceramics Monthly over a number of years may account for some repetition of content. Since there is so much to cover, I will give some sampling of Zamek’s offering.
Part I: Learning About the Craft and Materials.” Chapter 1 is devoted to “A Potter’s Education.” Chapters 2 through 5 deal with selecting and buying raw materials from several different perspectives. Chapter 6 is entitled “Avoid Potential Problems Selling Pots.” This outline demonstrates just how wide ranging is Zamek’s coverage.
Chapter 3, in Part I, is entitled “How to Buy Supplies.” While this may seem a self-evident topic, I wish that I had had Zamek’s advice before I began to stock my studio. For example, when moving chemicals in preparation for my studio renovation, I recently found a 25 pound bag of black iron oxide; I have not used black iron more than once or twice in my life. Had I read Zamek years ago, I would not have 25 lbs. of Black Iron Oxide using up space. In this chapter, Zamek notes that ceramists are not the primary purchasers of ceramic raw materials (i.e., clay and glaze supplies). Large industries drive the market. Zamek reminds us of this phenomenon later in his Chapter 18: Raw Material Substitutions for Glazes.”
Buying supplies can be difficult. How much does the potter buy of what? Zamek says, “You should be aware that many materials change over a period of time between two purchases of clay [or glaze materials]. Before giving up all hope, consider that some raw materials do remain fairly consistent in chemical composition, particle size…, and quality control” (p. 17): silica, whiting, dolomite, EPK, Custer feldspar, G-200 feldspar, Nepheline Syenite, Alumina hydrate, any of the frits, talc, and the opacifiers. Some materials are notoriously unstable because as they are mined, the chemical composition will probably change. Zamek cites Gerstley Borate as a prime example. (He devotes Chapter 13 entirely to the instability of Gerstley Borate and Colemanite. Since the research for this work occurred in 1997, much of what Zamek has to say on this topic is out of date. Colemanite has not been available for a long time, and Gerstley has changed to such an extent that old glaze recipes are being reformulated using frits to provide the necessary ingredients.) Zamek’s advice is to buy larger quantities of materials that are subject to change and to ask for chemical analysis from the manufacturer or distributor each time you purchase (often difficult to those of us who may only buy small quantities for reasons of use or space).
Since Part II: Clay Bodies is primarily devoted to creating and adjusting clay bodies, I have decided to skip over this section since very few of our readers make their own clays and since quality prepared clays are available from many different sources. If you do want to make your own clay, I recommend reading this chapter; it is filled with good advice and solutions.
Part II: Glazes: What Should Go Right—What Can Go Wrong. For me this is the heart of the book; here Zamek’s problem solving ability really kicks in. Chapter 12 deals with preparation for glazing, including bisquing. He repeatedly urges a slow bisque fire.
Chapter 14: Eight Steps to Stop Crazing has saved several glazes for me. Here are just a few of his eight tips: “Crazing can often be eliminated by a thinner glaze application” (p. 135). “Add increasing amount of flint [silica], the finer the mesh the better” (p. 6). For example, one might add silica in 3% increments: 3%, 6%, 9%. Since most of us buy and use 200-mesh silica, we might shift to 325 mesh, usually at no extra cost.
Next, to prevent crazing, Zamek says, “Fire the glaze kiln to the correct cone over a longer time. During the last quarter of the glaze firing cycle, try stretching out the firing by two or three hours. This will give the clay the best chance to tighten up or reach its maturity, which will help in achieving a good glaze fit” (p. 137). Still another important tip: “Slowly cool the glaze kiln. Don’t open the kiln door until the temperature is below 200°F. The kiln should be cool enough to unload without gloves….If the pots ping when the kiln door is open, the glaze is under stress and is more likely to craze” (p. 137).
Chapters 15 and 16 deal with shivering and crawling. He explains possible causes and offers easy solutions. You should check this chapter if these much less common problems occur in your clay work.
Chapter 17: Color and Opacity for Base Glaze Formulas, though very interesting, shifts the focus for this section of the book. Using cone 6 recipes as his temperature range, Zamek urges potters to develop a good clear, a satin, and a matt basic glaze recipe to serve as the basis for opacity and color adjustments. This is a most sensible body of material. I am, however, bothered only by Zamek’s use of Cobalt Oxide in several of his glazes he typically uses 5% Cobalt Oxide, a considerable and potentially unstable amount. Since most potters use the Carbonate form of Cobalt, you need to convert by multiplying Zamek’s 5% by approximately 1.5, which will yield 7.5% of Cobalt Carbonate. That would produce an extremely dark blue and might not prove stable for functional use. One of his glazes uses 10% Cobalt Oxide, which translates to a whopping 15% Cobalt Carbonate!
Part IV: Safety in the Studio begins with a previously published article, “Is Barium Carbonate Safe?” Zamek’s conclusions are that Barium can be safe if handled correctly. His major warning is against ingestion and inhalation. “Protecting yourself from inhalation by wearing a dust mask is a precautionary step that removes short or long term hazard due to inhalation and ingestion” (p. 191). Since there is an ongoing and even heated discussion among such glaze gurus as Ron Roy and Edouard Bastarache about the dangers of Barium Carbonate, I feel that if such knowledgeable glaze experts cannot agree, I will refrain from using Barium. On might always more safely re-formulate a recipe by using a frit that supplies Barium; Ferro frit CC-257 is a good example.
Chapter 23 is called simply “Black Friday.” Here Zamek tells the endearing story of his black Labrador named Friday. At one point, Zamek describes Friday in his sixth year enjoying being with his master in the studio: “Friday was solid black, almost blue black…. I kept the studio very clean, but there was always a gray side to Friday. He was at his best in his resting or thinking position. His big brown eyes would follow the kickwheel around and around. Just looking at his eyes dart around made me dizzy. There’s something to be said for a single digit IQ because he never found this activity (or lack of activity) too dull or boring. He was just glad to be with me” (p. 201). When Friday died, Zamek had Friday cremated. He decided to use some of Friday’s ashes in a glaze, which he called “Black Friday Glaze Cone 6/ox,” published at the end of the chapter. Shortly after Zamek’s book was published, Ceramics Monthly printed the “Black Friday” chapter in one of it issues.
Finally, Part V: Clay Body and Glaze Formulas. He provides a number of clay body and glaze recipes mostly for cones 06, 6, and 9-10. All of the glaze recipes are base recipes to which you might add opacifiers and coloring oxides. While I am always pleased to find new cone 6 recipes, I would have liked to have some description of the base glazes and perhaps their reactions to additions; instead Zamek lists, for example, 9 glazes simply called “Zam #1 Clear, Gloss” through “Zam #9 Clear, Gloss” (pp. 215-17).
Zamek’s sometimes random organization does not make the book less valuable. My negative comments are only minor. The table of contents is clear; his index at the end is quite thorough. If you have a problem or want to understand a process, you can easily find your way to the spot in the text.
I give this book a very high recommendation for all its valuable information. In addition, it is a good “read.” I find myself re-reading a chapter on occasion because I was not ready for the information the first time through. As I grow in my own knowledge about ceramics—and particularly about glazes--books like Zamek’s are increasingly more comprehensible.