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Kiln repair
now available in So. California area
We now offer full service kiln repair &
service in the Southern California area:
To schedule kiln
service, call us at 818/782-1500
Q:
How do I fire the kiln to prevent pieces from "exploding"?
A: Slowly. The cause of the legendary "exploding" pot
is almost always steam, that right, steam from the leftover
water in the pot. Water turns into steam at 212°F, so the
key is to keep the kiln below that temperature until you are
certain all the pieces are really dry. Potters call this
technique "candling" or preheat.
Q:
What is the best way to load a kiln?
A: The results you get from a kiln depend greatly on
the methods you employ when you load the kiln. Since most of
the heatwork is accomplished via infrared heat transfer it
is very important to load each shelf with lower pieces on
the edges and taller pieces in the center of the shelf. This
will afford every piece on every shelf a good cross section
of IR heat.
Q:
Which type of clay would be good to get started with?
A: There are 2 main types of clay that are popular in
school settings. Earthenware (lowfire) and Stoneware (highfire).
Our recommendation would be to get started with nice white
earthenware clay body. Now, you need to remember we aren't
clay experts (but we can sure fire it). One key to your
success is probably to find a full service distributor and
purveyor of ceramic supplies. They are a wealth of knowledge
in all aspects of firing ceramic products (we'll stick with
making great kilns, OK?) You dont have to go far to find
us!.
Q:
What is a bisque firing?
A: The first firing which will take a raw & fragile
piece of clay to a durable ceramic object. This firing
should not be confused with the 2nd firing which generally
is referred to as the glaze firing.
Q:
When can I glaze a clay piece?
A: After a piece has been through the initial bisque
firing. Then glaze (sometimes called color) can be applied
to the piece.
Q:
Which firing speed should I use?
A: Slow. The mantra with hand built or wheel thrown
pieces is: when in doubt fire slower.
Q: Does my kiln need to be ventilated?
A: Yes. In most school settings the building codes
require kilns to be ventilated. Local codes vary, but there
are very few exceptions.
Q: How often should I use pyrometric cone with my digital
kiln?
A: Or better yet, what is a pyrometric cone? Well a
cone is 2" tall piece of specially formulated clay that will
tell you how much heat the objects on the kiln shelves
received during the firing. They "indicate" this heatwork by
bending from almost vertical at room temperature (no bend)
to 90° (angular) a perfect firing.
Now,
on with the main question. Over time the temperature probe
in a digital kiln (called a thermocouple) will decalibrate.
By using at least 1 cone every firing you will be able to
keep and eye on the thermocouple. When the cone ceases to
bend properly (range: 40<good firing<95 angular degrees) you
should replace the thermocouple.
So as
you can see utilizing pyrometric cones periodically will
keep your kiln firing the way we both intend it to fire.
Q: OK, my Principal just told me I'm in charge of the
clay program, now what?
A: If you are like a lot of Art Teachers you have had
excellent training in many areas, but are perhaps lacking
the confidence needed to get you feeling comfortable with
clay, glazes and the kiln. Don't fret, you aren't alone.
Call us and we can help in all areas of your project.
You're
right to have a healthy respect for the temperatures that a
kiln reaches. But we can help you understand how the kiln
manages that extreme heat and how safe the units are.
Simple & Important safeguards for operating a kiln.
Please read and
observe the following safety warnings before operating your
kiln:
Install kiln
18" or more from any wall or combustibles.
Fire only on
stand or legs furnished.
Never fire
hotter than cone 10 or 2350 degrees.
Do not fire
hotter than the manufacturer's recommendation for your clay,
glazes, or decals, or permanent damage may result to your
kiln or ware.
Do not open lid
until kiln has cooled.
Before opening
lid, turn off all switches, then carefully open lid and test
that lid brace is securely engaged before allowing lid to
stand freely.
Do not leave
kiln unattended while firing.
Never use an
extension cord.
Operate kiln
only in a well-ventilated room.
Unplug kiln
before servicing or cleaning.
Dangerous
Voltage - Do not touch heating elements with anything.
Do not touch
hot sides of kiln or hot lid. Burns may result.
Never store
anything under kiln; never lean objects against kiln.
Do not store or
use flammable liquids or sprays in the same room with your
kiln.
Do not store or
use your kiln outside; keep rain and moisture away from
kiln.
Do not use kiln
if cord is damaged.
Wall receptacle
must not be corroded.
Use kiln only
with adequate electrical supply and with the correct
voltage, amperage and correct fuse size (not too large or
small). Be sure the wire size is large enough (avoid
aluminum wiring). Do not use a 208 VAC kiln on 220 VAC.
Kiln must be
grounded properly.
Wear goggles
when looking thorough peephole.
Wear protective
gloves when handling hot peephole plugs.
When firing
objects to be used with food and drink, use only supplies
tested and labeled "safe" for such purposes.
Avoid breathing
fumes from materials being fired.
It is imperative
that you read all instructions and follow
ALL of the manufacturers instructions and recommendations before
operating the kiln.
These are very
simple guidelines, there is so much more to know before you
are ready to use your kiln.
Electric Requirements of Kiln (Volts &
Amps)
Most small test kilns (1 cu./ft.) can be fired on a standard
110-volt outlet, and only draw 15 amps. However, larger
kilns require more volts and amps. Ask your electrician what
the available voltage is to your kiln room. The voltage
supplied might be 208 or 240 volts. Note the voltage when
ordering the kiln. If your voltage supply is 240 and your
kiln requires 208 volts this situation will shorten the life
of the kiln elements and switches. If you voltage is 208 and
the kiln draws 240 volts the kiln might not reach its
maximum temperature during the firing. The goal is to match
the kiln to the power supply. When you have selected a kiln,
ask the ceramic's supplier the voltage and amperage (amps)
requirement of the kiln you are considering purchasing then
relay this information to your electrician so he can
determine the correct electrical connections when the kiln
is in place.
A Reputable Ceramic Supplier (An
Important Choice)
Before purchasing any ceramic supplies or equipment consider
the company that stands behind their product or service.
This will be the most important decision you will make when
purchasing an electric kiln. Look for a local ceramics
supplier who has a good business reputation and offers full
service to its customers. It is best to buy from a "full
service" dealer with a good reputation.
Click here for some places to kiln fire your
ceramics in the US and Canada
Happy &
Safe Firings!
