Skutt KilnMaster Kilns Manufactured between 2000 and 2006 - Manual (Page 16)

14
G LAZE F IRING
Glaze firings require that you have kiln
washed the bottom of the kiln and one
side of each shelf. Glaze will stick perma-
nently if you fail to keep a good coating of
kiln wash on these surfaces.
Don’t let any of your pieces touch one
another or the side of your kiln.
Stilts are devices used in glaze firing to
elevate the fired pieces from the shelves.
There are many styles. Use those that
provide the widest bearing capacity for
stability. If a piece wobbles on its stilts, it
may tumble during firing. Make sure you
have a good solid base.
“Dry-footing” a glazed piece will elimi-
nate the need to stilt your ware. To dry-
foot, avoid glazing the base of your piece.
Or you can apply wax resist to the base
which will cause the glaze to puddle up,
making it easy to remove with a damp
sponge. Any part of the ware that will
touch the shelf cannot have glaze on it.
Leave all possible breathing room
between pieces for best firing uniformity.
Ware should be at least 3/4” apart on the
shelf or bubbles and fumes may contami-
nate adjoining pieces.
P ORCELAIN AND S TONEWARE
F IRINGS
These materials differ only in purity of
clays, although they appear different in
color and texture. By definition, both must
be fired hot enough to render the bodies
waterproof (or vitreous) at which temper-
atures they tend to wilt.
Because the bodies become soft, they
must be bisque and glaze fired resting flat
on a freshly kiln washed surface, or one
sprinkled with silica flour (flint). Flint
must be kept out of the element grooves.
Remember to vacuum the grooves period-
ically.
Be sure to check clearance at the top of
your porcelain load with a ruler so that
pieces do not touch the lid and stick to it.
To avoid distortion, pieces must either
be carefully designed or the overhangs
specially supported. Figurine arms are
generally supported by hollow greenware
pillars, made of the same clay material.
These will shrink along with the piece,
which in high firings can be as much as 12
percent.
Simpler shapes such as wide plate rims
are generally supported by reusable rings
(setters) made of even higher firing mater-
ial specifically shaped for that one article.
Both porcelain and stoneware glaze fir-
ings are dry-footed to prevent fusion to
the shelves.
O VERGLAZE F IRINGS
Stilting may be helpful because it allows
heat to penetrate between the ware and
the slower-heating shelves. Large double-
pointed stilts can be used to hold plates
apart when fired on edge.
G LASS F USING AND
S AGGING F IRINGS
When firing with more than two shelves,
the lower one is usually posted well off
the kiln floor and the upper one is placed
at least 3” above the first mold. The center
of the load should fall a bit above the cen-
ter of the kiln.