Specifications

Apply three thin coats (milk consistency) to the top of
each kiln shelf with a large house brush. Allow to dry
completely before firing. Kiln wash is not applied to the lid,
sitter, elements, or the undersides of the shelves. Kiln wash
will last many firings and it is not necessary to reapply
unless the surface has flaked or has a lot of glaze build up on
them. Simply scrape off any buildups of glaze with a putty
knife. If glaze remains on the shelf, use a belt sander with
coarse grit to remove it and then reapply kiln wash. A new
application of kiln wash is required prior to firing any glass
in the kiln.
Peepholes
Peepholes are exactly what the name infers: openings in
the kiln wall that allow you to view inside the firing
chamber. They allow air circulation into the kiln chamber
and permit fumes and gases to escape during firing.
Peepholes can have either plugs or hinged coverings.
The top peephole should never be closed in a standard bisque,
glaze or luster firing until the kiln has shut off. The lower
peepholes should always remain closed throughout the firing,
as they can cause two things to happen. An open peephole
can chill the shelf cone causing it to perform inaccurately.
Leaving the peepholes open during any kind of firing can
cause a piece to fracture due to a draft onto the ware. When
firing glass, all peepholes should be closed during the entire
firing to prevent cold drafts from fracturing the glass.
Stilts
Stilts are bisque platforms with nichrome wire points that
keep the glaze pieces from adhering to the shelf. They come in
various sizes and heights, allowing the best heat and air circu-
lation to the ware during firing. Most stilts are composed of a
three prong configuration to give the best degree of stability to
the ware. There are also multi-pronged stilts for accommo-
dating larger items. Use the largest stilt to fit the size of the
piece to ensure support. Taller stilts should be used for bright
bisque red and orange glazes for better air circulation.
Maintain your stilts by cleaning the points regularly with a
pair of pliers; if the stilt has a glaze-like surface, it needs to be
replaced. Use of old stilts can discolor the glaze on the piece.
Firing's Four Basics
Understanding the basic equipment now leads us to what
happens during the firing process. There are four very
important factors required to complete a properly fired piece:
Time, Temperature, Air Circulation and Ventilation.
Other factors that happen during the firing are: air expansion,
ware shrinkage, and how all these factors interact.
• Time is the length that the piece is subjected to heat.
• Temperature is the degree of heat required to mature
the piece. Time and temperature combined are referred
to as "heat work." This is a very important term to
know and understand.
• Air Circulation is the way movement of air occurs in
the firing chamber.
• Ventilation is the removal of the fumes and gases
during the firing. Air circulation and ventilation are
independent and are often confused.
Venting Systems
New kilns come equipped with mechanical ventilation
systems; older kilns can be retrofitted with them. Systems
that pull the air through a hole(s) in the top of the kiln
maintain a more even temperature throughout the firing
chamber. The oxygen that is pulled through the opening(s)
allows the glazes to develop better during firing. Never place
a piece directly below one of the top vent holes; it can cause
a cold spot on the piece, making it crack during firing.
Firing Preparation
•Maintain your kiln by vacuuming on a regular basis,
and making sure the kiln sitter is adjusted, as they can
become out of line over time.
•Glazed ware or greenware with trapped air pockets (for
example, hollow arms or handle attachments) should be
vented.
•Greenware and glazes should be bone dry. Unnecessary
moisture can affect the glaze or ware, creating bubbles,
craters, glaze crawling, or explosion of the piece.
• Pieces glazed inside and out take longer drying time.
•Turn kiln to OFF.
Loading the Kiln
Keep the four basics of firing
(time, temperature, air circulation
and ventilation) in mind
when loading the kiln.
When arranging the ware,
consider the heat penetration.
Air and heat cannot circulate
on the kiln floor. Therefore,
the first thing to do is create
a "false bottom" on the kiln
floor. Place three
1
⁄2” posts
under a kiln shelf; this shelf
will remain in the chamber at
all times. The improved air
circulation and heat distri-
bution helps overcome stress
in the pieces and other problems in subsequent firings, like
crazing, pinholes, cloudy glazes and ware warping.
Heating every piece evenly requires you to load a
variety of pieces on each shelf when possible. Never put all
of the same shape on the same shelf.
•Agood rule to follow when placing pieces in the kiln is a
minimum of two finger spacing for greenware and three
finger spacing for glazes (approximately 2
1
⁄2
".) Increase
spacing to four fingers (approximately 3
1
⁄2
") for glass
firings. If you are firing a smaller load, increase the
spacing and spread the ware evenly around the kiln.
• Lids should be placed on the piece during a greenware
firing. Never put pieces inside larger pieces during firing.
•You may prevent warping by "boxing" cups and placing
them rim to rim on top of one another during a
greenware firing.
10
Firing
If a glazed piece feels
cold to the touch, it
indicates that the
piece is still damp
and needs additional
drying time before
firing.