Firing is very costly. Likely to get more so. It
is a serious matter, a budget breaker, and you must be very sure you can
afford it you before you commit yourself to these expenditures.
Move slowly and carefully. It was very "in" some
twenty, thirty years ago to build one’s own kiln! Gas was cheap, wood
easily obtained, and there were, as yet, few regulations.
For those with rural property the building of a
fuel burning kiln still is feasible. Costly, time consuming, but
feasible. In suburban areas and cities permits and the like are
required, and a gas company, for instance, may refuse you a big enough
tank in a residential area. Check, double check, check again!
"Artistic" defiance of rules and regulations can
lead both to tears and lawsuits. So it is only after you have checked
all zoning and fire regulations and talked to your insurers--and, if you
rent, your landlord--that you go kiln shopping.
Electric kilns --long used all over the
worlds--became more popular, and more “respectable” in the US in the
past decade .
Manufacturers, models, and features have
increased. Again check and double check before you buy.
No matter what size kiln you get: there are
several excellent brands and a great many models to choose from . There
is a division among kilns: the standard, and the heavier, more insulated
kilns. The first are known as "hobby" kilns, although many professional
potters use them. The latter are seriously heavy duty kilns often with
steel outsides, and "extreme" insulation. Today both kinds come with or
without computer controls. The controls have many advantages--but add
greatly to the kiln's cost.
A kiln is very much of a "deal breaker". While
they last "forever" if treated well, they are very costly, and, it
should be added, do NOT benefit from being moved.
It is the cost of the kiln and the fuel to fire
it that is the determinant in whether you set up your own studio. Write
away for all possible information. Visit as many showrooms as you can.
Try to check with schools and potters in your area before you shell out
that kind of cash.
1. Buy a test kiln kept for tests, and fire your actual pots in a
kiln where you rent space. Many test kilns use regular household
2. Buy a medium-sized kiln in which you can fire
tests as well as your pots. Medium-sized kilns are best for beginners.
You want a kiln you can fire once a month--especially if you are working
on glazes and need to fire tests. Such kilns require 220v current, which
requires enough electricity coming into the house. That may demand a
bigger “entrance” (the place where the electricity comes in). You must
check with then utility before you buy the kiln!
3. Get a big kiln. Fire maybe every two months.
If you make large pieces a large kiln is your only choice. But you
certainly do not want to fire a kiln half empty! Firing half empty not
only wastes money, it does not produce as good results. The kiln need
not be in your glaze room. It must be in a place where it can be
properly vented, and in which it is not a fire hazard. There are
different venting systems and to find the right one takes a lot of
checking. Do not expect to make your kiln decision and purchase in less
time than it takes to buy a car!
BOOKS, NOTES RECORD KEEPING --ESSENTIAL PAPER
Record keeping is the heart of glaze development. No matter what
approach you take -- empirical or more scientific--you must keep track
of what you are doing, what you did.... and why.
Records can be kept on 3 x 5 cards, in
notebooks, on the computer.
Details do not matter. You must set up a system
that works for you, allowing you to access, with reasonable speed, glaze
recipes and notes that you made last week--or ten years ago.
Everyone develops a personal way of naming and
identifying glazes and glaze tests. Any system will do, if kept simple
and clear! Upon your record keeping depends your success.
AS TO REAL BOOKS.
The Public Library can supply you with a great many books on clay.
Daniel Rhodes "Clay and Glazes for the Potter" and "Stoneware Glazes"
are readily available, and, while outdated as far as health issues go,
are well-written, excellent sources of information.
You need a good current book on safety issues.
It should be the first book you buy! We recommend Monona Rossol's
"Artist's Complete Health and Safety Guide“, the latest edition.
As your basic texts: "Glazes for the Craft
Potter," and "Ceramic Faults and Their Remedies", both by Harry Fraser:
clear, exemplary books, that will prove your constant references.
Emmanuel Cooper has several books on glaze and
electric firing--but these can be had only on the used book market and
Robin Hopper's "The Ceramic Spectrum" is an
excellent book, becoming more affordable second-hand. Libraries are
likely to have it.
If you plan to fire at c. 6 electric both "Mastering Cone 6 Glazes" by
John Hesselberth and Ron Roy, and Michael Bailey's “Glazes Cone 6" are
primary texts. They are quite different, both very good.
And "Glazes: Materials, Recipes and Techniques",
a collection of Ceramic Monthly articles, edited by Anderson Turner is a
wonderful source for all sorts of glazes and excellent advice.
ALWAYS REMEMBER that safety standards and
regulations have changed and become stricter over the years. Remember
that older books, or older editions of books still in print, or older
magazines, may be contain unacceptable recipes, and suggest materials we
no longer use. ALWAYS double check recipe contents in a book such as
WHERE TO BEGIN?
1. Read several of these books and decide what you want to do. You
may want to test a whole variety of glazes. After all you have read you
will know that high magnesium, zinc, nepheline syenite, strontium all
affect glaze results differently. You may want to start by testing some
glazes in each group.
Or you may want to achieve a certain look. A
certain color. And you will need to make tests and more tests to get
that look just right.
Likeliest will be that, for starters, you want
to check out glaze recipes that fit in with the pots you are making. You
"inherited" some recipes and want to make sure they work correctly on
the clay body you are using.
2. MAKE TEST TILES. Every potter seems to have a
preferred shape test tile. Some throw or extrude
cylinders--approximately 2" in diameter—that then are cut into 2" rings.
(They look a lot like napkin rings)
Others throw wider cylinders and cut them into
rings, which then are halved, forming arches. Some make very small
bowls. The most common in this country seems to be the L or T shaped
test tile--which can be thrown (a wide, low ring sliced up like a pie)
If you have neither wheel nor extruder, try
this. Roll out a slab of clay about 1/4 inch thick and 3 or so inches
wide. Drape it over a 2" mailing tube, or an empty paper towel roll. Let
it get leather hard, and cut into 1 1/2 inch slices. Clean them up so
that they stand properly on "their own two feet" and you have excellent
U shaped test tiles!
Carol makes her like this: She throws a small
sphere off the hump, a shape like an orange and about that size. When
the "orange" is leather hard, she cuts it into wedges--exactly as one
would an orange. Each wedge acts as its own "saucer"--as the curved
shape contains any glaze that runs!
It does not matter what shape you choose. But
the test tile must be big enough so you can see what is going on. Again,
methods vary. Some people mark their test tiles when leather hard. This
can be done by scratching in an ID or by stamping in the ID with a
rubber number stamp (about $5 at a stationer's) or stamping in letters
from a child's "printing" set. The test tiles then are bisqued. When the
tile is used, its ID is entered next to the test description on the
Other people bisque their test tiles, and marks
them with an underglaze pencil as they are used. You need to test tiles
for the body you are using and for the other three bodies as well. You
will NOT need to test every glaze on all the bodies. But if a "given"
glaze recipe gives you trouble, testing it on other bodies will help
identify the problem.
Test tiles can be striped with white and black
slip. Ridges on them allow a glaze to "break" and reveal potential
patterns. Besides test tiles you might make some tiny test cups by the
following method, we learned from a ClayArter who prefers to remain
anonymous. Roll out some clay, and with a large sewing thimble make a
series of depressions in it. You can cut the slab up as you wish. The
depressions are filled with materials to be tested for fusion.
MAKE SOME BISCUITS
You will, alas, soon enough have a damaged shelf you then reserve
Meanwhile, make yourself a number of
"biscuits"--pancakes of clay, preferably grogged, to put under test
tiles when you do not know how much the tested materials will run. You
may prefer to make the "biscuits" for your first tests with a rim--like
little pie-pans--in case the glaze REALLY runs!
GETTING TO WORK
Alright. You have your glaze room, your table, your materials, your
test tiles. You are ready to go.
Now what? Where do you begin? You have read several of the books suggested--or
others--and you have an idea what you want to do.
You may want to test different materials. For
this you would place a small amount of the material in one of the little
thimble cups and fire to the chosen cone/temperature. You may want to
test different glaze recipes you have. For this you weigh out and mix up
the materials and apply the mix to test tiles.
You may want to see what difference replacing
one material by another makes. Again you weigh out and mix up your
materials and make up a glaze you apply to a test tile. Now there are
several methods, ways, of doing this. And these should be tried out till
you find one you like, can stick with, and that works for you.
One of us prints out the recipes--or mixes-- to
be tested on her computer. She pastes each recipe to the container where
the test will go, crosses off the ingredients as they are added to the
The other uses paper with little squares printed
on it. Across the top of the sheet she writes the names of the materials
to be used. Down the left margin: the names or ID of the glazes or
tests. On a line with the glaze name the amount of material that glaze
wants is entered in the material’s column. As the material weighed out
and added to the test container, it is checked off on the paper.
What containers you use to mix your tests in are
up to you. Old yoghurt or cottage cheese containers work well, as do
disposable plastic “glasses” The important thing is to have solid
containers, that you mark clearly! Here too systems vary. Some use
letters and numbers to identify glazes being tested. A test series might
be Jan/09/A, Jan/09/B with numbers added for the next (Jan/09/A1) and
next and next test--and so on. Others prefer actual names. This is
mostly done when one tests another person’s glaze. Cooper 163, or Cowles
Mope, or Thorpe Cornwall Stone. As said letters or numbers can be used
to identify tests in series. The only important part of this is that you
mark your tiles clearly, that you keep good records, that you do the
WHEN THE KILN IS OPENED!
After the tests come out you need to sit down and examine them.
Both good light and a good magnifying glass are a must. We suggest a
magnifying glass with 10x magnification, as well as one with 30x
Look at each test tile carefully. Ask the
questions. Did this test mature properly? Did it underfire? Overfire?
Craze? Bubble? Write your observation down in whatever record “book” you
Assuming the glaze turns out perfect, test it
on an actual pot. One of us makes 200 gram test batches, the other 100
gram. The latter never is enough to test on a pot--so a new and bigger
batch is made up. While that sounds like extra work, it is an excellent
control on whether the original was weighed out correctly! Assuming the
glaze has defects. Hit the books and try the remedies! Keep excellent
notes all along the way, and for every step. That is how you learn! In a
few years you will know “instinctively” what is what...and need to
consult your notes less often. Till then it is upon your record keeping
that your success depends.