Tip #83: Single Firing
Most pottery is fired twice (or in some cases 3 or
more time!). The first firing is called the bisque, then there is a second
firing for the glaze. This is the
way you probably learned, and they way you probably do it. But
it is possible to fire only once.
In fact, ancient pottery, such as Chun Pottery, was often only
fired once. This is called
“Single Firing” or “Once-Fired Ware”.
There are many advantages to doing two firings.
 | Glazes
are easy to apply. You
don’t have to worry about the piece absorbing too much glaze and
coming apart. |
| If
you apply your glaze poorly, you can wash it off. |
| You
can more easily do decorative techniques where you apply a remove
glaze (for example, to wipe off the high spots of a textured surface.) |
| If
your piece is not dry it can “explode” in the kiln.
Without glaze on the pieces, this doesn’t hurt anything
(except maybe neighboring pieces.)
But if that piece were covered with glaze, the pieces would
stick all over the kiln. |
| Organics
have a chance to burn off in the bisque firing, so they don’t affect
the glazes. |
The advantages of single firing are:
| Less
work |
| Less
power used |
| Some
people feel they get a better clay-glaze interface, or they prefer the
process of making the piece all at once instead of in stages where
focus is first on form, then on decoration. |
Not all glazes can be used for the Single Firing
method. The glaze should have
a high clay content. Beyond
that, a lot of testing is required to find a combination of clay and glaze
that works consistently for you.
To summarize, there is a good reason why most people
use two firings. You do have
more loss with single firing. (In
addition to pieces cracking you tend to get more crawling and pinholing.) So most people believe that in the long run, it is not any
more efficient. But it is
possible, and some potters have found ways to do it successfully.
Perhaps there will be a resurgence
of interest in Single Firing as fuel costs continue to rise. But it
certainly would not be recommended for a one-of-a-kind piece that you
spent months on.
copyright Cindi Anderson BigCeramicStore 2008
|
|
