Bruce Girrell on mon 1 jan 01
Ceramic Science for the Potter
by W.G. Lawrence and R.R. West
Second Edition 297 pages
Chilton Books
ISBN 0-8019-7155-1
I got this book on interlibrary loan at the recommendation of others
on the list when I posed a question regarding thermal shock resistance
of clay bodies.=20
Some of us on this listserv want to make art and the materials are
simply the means to a goal. If something doesn't work, it gets
discarded or modified. If something works, it is repeated or expanded
upon. Others are driven to understand _why_ the cracks appear or _how_
to make the materials do the things we want. Neither approach is right
or wrong, but this book is definitely for the latter group. The
authors say it this way: "Unexpected or disappointing results may
ultimately be corrected on a trial-and-error basis but usually at the
expense of great time and effort. For those who have made such
mistakes and who wish to understand their material more thoroughly,
this book will be useful."
Don't be concerned that the material is too advanced, though, if all
you are lacking is experience in ceramic science. The authors assume
no particular scientific knowledge above high school chemistry. If you
can recognize the chemical symbol for common elements and know what
valence means you're in good shape. While the subject matter is
naturally technical, Lawrence and West try to keep things down to
earth. For example, to provide you with a sense of how small clay
particles are, they provide this table:
1 cm --> peas
1 mm --> fine shot
0.1 mm -->talcum powder
0.01 mm ->amoeba
1 micrometer --> small bacteria
0.1 micrometer --> large colloidal particle
0.01 micrometer -->large molecule
The authors cover techniques from simple measurement of dry and fired
shrinkage to the construction of a thermal gradient furnace and
differential temperature analysis apparatus. If you happen to have an
atomic absorption spectrometer hanging around in your closet, they'll
tell you how to perform a test for lead and cadmium leaching. I think
I'll just send mine to Alfred.
After reading this book I think I finally have a handle on
flocculation and deflocculation. Also, I have been slinging around the
term "cation exchange capacity" for years (from oilfield experience
with clays). Now I understand what I was talking about.
Ever wonder why your pot lid didn't fit after drying even though you
measured it properly when you made it? Why did mold marks appear on
your fired casting even though you cleaned them up perfectly? Why did
your piece crack despite the fact that you candled the daylights out
of it to make sure that it was completely dry?
I think the authors did a very good job of conveying the basics of
some very technical material in language that is understandable to the
average person. My only regret is that they often seemed to stop short
of really getting into the meat of some subjects. This book has nearly
300 pages, yet I kept wishing that they would explore many of the
topics in more detail. Given the range of topics covered, if I had my
way, this book would be about the size of an encyclopedia.
Chapters:
1 An Introduction to Ceramic Materials
2 The Nature of Clays
3 The Clay-Water Relationship
4 Clay Slips
5 Plastic Properties
6 Drying
7 Particle Orientation Effects
8 Whiteware Bodies
9 Firing
10 Air Pollution
11 Glazes
12 Salt Glazing
13 Terra Sigillata
14 Thermal Shock Theory
15 Thermal Shock Bodies
16 Lead Glazes, Their Use and Misuse
Because I'm an engineering geek kind of guy, I found this book useful
enough to buy, but it is unfortunately out of print. Books like this
just don't seem to stay on the best sellers list for very long.
Bruce "thank goodness for libraries" Girrell
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