Author: Harry Fraser

This new edition of Harry Fraser's classic book on glaze technology and practice discusses not only the calculation of glaze composition, but also the preparation and production of glazes. He addresses application methods and how to remedy faults that may occur. This comprehensive introduction to glazes and glazing features a new chapter on health and safety issues, and the book includes new photographs and a color section.

About the Author
Harry Fraser is currently the managing director of Potclays Ltd, a large pottery supplier. He has over 30 years of experience in the field of clay and glaze technology that makes him especially qualified to write this book.

Price $28.95  

• Introduction: early glazes, Egyptian paste, purpose of glazing, once firing and twice firing
• Classification: methods, Raku, terra cotta, earthenware, stoneware, porcelain
• Difference in technique between craft and industrial potters
• Reduction

• Elements, compounds and mixtures: atoms, atomic weight, compounds, molecules, molecular weight, formulae, mixtures
• Solutions and solubility, suspensions, saturated solution
• Crystallography and structure, crystal lattice, glazes and glasses, Zachariasen random network theory, glaze definition
• Coefficient of expansion
• Strength of glazes and glazed pottery, Griffith theory

• Melting and fusion, sintering, the fusion process, dissociation, convection currents
• The fluid state, viscosity of molten glazes, importance of viscosity, alumina
• Volatilization
• Surface tension, adhesion, surface state
• The buffer layer
• Cooling considerations, importance of rate of cooling, crystal formation, liquidus point

• Glass formers
• Basic oxides, amphoteric oxides, acidic oxides
• Adjustment of bases to unity
• Seger ratios and formula
• 'RO' classification

• The basic oxides: oxides of lead, potassium, sodium, calcium, zinc, magnesium, barium, lithium, and strontium
• The amphoteric oxide: alumina
• The acidic oxides: boric oxide, silica

• Igneous, sedimentary, and metamorphic rocks
• Feldspar, Cornish stone, nepheline syenite, basalt, china clay, dolomite, whiting, magnesite, talc, fluorspar, colemanite, cryolite, potassium carbonate, magnesium carbonate, zinc oxide, borax, galena, lead carbonate, lead oxide, red lead, litharge, lepidolite, petalite, quartz, alumina, wood ash

• Molecular and formula weight, importance of molecular formulae, relationship between percentage composition and formula
• Calculations involving recipes, formula-to-recipe and recipe-to-formula conversions, calculations involving fritted glazes

• Lead in glazes
• Lead poisoning, hygiene
• Purpose of fritting
• Effect of soluble materials, borax, alkaline frit
• The fritting process, continuous and intermittent
• Lead solubility regulations
• Low-solubility regulations
• Low-solubility glazes, importance of particle size
• 'Coated frits'
• Thorpe's ratio
• Fritting on a studio scale

• Modern problems: acid attack, acids in foods
• Metallic compounds of concern
• Lead release limits, method of testing, sampling technique
• Studio test
• Lead release from commercial glazes and on-glaze enamels
• Problems of glaze additives
• Lead poisoning: historical evidence

• Opacification methods: crystallization, diffusion
• Refractive index
• Particle size importance
• Dispersion
• Tin oxide, zircon, zirconium oxide, and other opacifiers

• The coloring oxides: oxides of iron, cobalt, copper, chromium, nickel, manganese, vanadium, and antimony, rutile, ilmenite
• Oxide combinations
• Prepared stains
• Stain compositions: blues, greens, yellows, pinks, reds, browns, black and grays
• Underglaze colors
• Colored glaze preparation and control

• Crystalline
• Aventurine
• Rutile
• Matt
• Satin vellum
• Flow
• Crackle
• Froth
• Lustre
• Localized reduction glazes
• Slip glazes
• Once-fired glazes
• Terra sigillata
• Raku
• Engobes
• Vapour (salt) glazing
• Ash glazes
• Chun Glazes

• Jaw crusher
• Grinding pan
• Fine grinding: general considerations, fritted and raw glazes, optimum particle size, the micron as unit of measurement
• The ball mill: operation, critical speed, grinding charge and procedure, drying out
• Ultra-fine grinding: principles
• The Vibro-Energy mill
• The Op-po mill

• Sieving, mixing dry ingredients, addition of gums and binders
• Consistency and adjustment, porosity of biscuit ware, slip viscosity and measurement, pint weight, hydrometer
• Binders and their use
• Silica paint
• Electrolytes, deflocculation, flocculation
• Glaze suspenders
• Colloidal particles and their influence, Brownian movement

• Various methods
• Dipping
• Pouring
• Spraying
• Painting
• Glaze thickness
• Glaze removal, wax resists

• Industrial and craft pottery techniques
• Firing speed, heat work
• Cooling speed, firing down
• Reduction
• Some important points: setting the ware in the kiln, cones and temperature control

• General considerations
• Determining the quantity, scales
• Method of testing
• Keeping records
• Line blends
• Tri-axial blends
• Checks to ensure consistency of successive batches
• Usual checking procedure

• Crazing
• The role of silica, effect of silica inversions, moisture expansion
• Peeling
• Scumming: on the biscuit, on the glaze
• Crawling
• Cut glaze
• Dunting
• Pinholing
• Matt glazes becoming glossy
• Devitrification
• Blistering
• Spit-out
• Droppers
• Overfiring and underfiring
• Bloating
• Color variation
• Change in color
• Specking
• White spot
• Starved glaze
• Sulphuring
• Dimpled surface

• Labeling of hazardous materials
• Ceramic material hazards
• Glaze materials
• Other considerations
• Recommended health and safety procedures
• Disposal of materials

Price $28.95