agent to keep the grains of enamel in place. Allow the enamel
to dry completely before firing.
Firing Enamel
1
Heat the kiln to 1450°F/787°C for most enameling.
Use a Single Segment. (Please see your digital con-
troller instruction manual.)
Rate
Temp.
Segment
°F/°C
°F/°C
Hold
1
1799/999
1450/787
01.00
Note:
Hold time should be the length of time you
will be inserting enameling into the kiln. In the
above example, hold time is for a one hour.
2
Lay the copper shape on an enameling rack. If the
part that touches the rack is enameled, place a stilt
under the copper. Some bowls or other shapes have
enameled sides that might run during firing. These
should be fired with a stilt even if the piece has a plain
bottom. Use an enameling fork or, if the rack is small,
a 6” putty knife, to place the rack into the kiln on top
of ½” ceramic posts.
Note:
Firing the piece at enameling temperature
should take about three minutes and requires undi-
vided attention!
3
Look at your piece every 15 seconds by cracking open
the door. Remove the rack when the copper piece ap-
pears a rosy red and the enamel is smooth. Place the
rack on a steel pad or large ceramic kiln shelf and let it
cool completely.
4
After counter enameling, you will need to clean the
fire scale off the front of the piece. A 3M Scotch
Brite® pad works well for this. Then clean it with
Thompson Sparex No. 2.
Ceramic Overglaze
Pyrometric Cones
Pyrometric cones are small pyramids of clay and mineral
oxide that soften and bend
when exposed to heat. They
indicate when ceramic ware
has fired to maturity.
Pyrometric cones come
in 1 1/8" and 2 ½" lengths.
Use the 2½” cones. Cones
mounted on the kiln shelf
must be slanted 8° from ver-
tical. They will not bend ac-
curately if they are slanted
to the wrong angle.
Self-supporting large
cones have the correct slant
built into the base. Stan-
dard cones must be
mounted in a clay or wire
plaque.
The chart on page 14
shows the temperatures of
pyrometric cones. Program
your controller to the cone
recommended for the ce-
ramic ware that you are
firing.
For small ceramic
pieces, such as figurines,
program a rate of
400°F/222°C. Fire to the
temperature shown in the
108°F column of the Tem-
perature Equivalents chart
for the cone number you
are firing.
Before deciding on the
firing speed of important pieces, test fire sample clay pieces.
Note:
Do not fire beyond your kiln’s maximum
temperature. Firing hotter will void your warranty.
Kilns with glass view port: do not fire hotter than
1700°F/926°C.
Loading and Firing
Overglaze
Overglaze is decoration applied over fired glaze or pol-
ished porcelain bisque. Overglazes include china paints,
gold, and luster, which fire from cone 022 to 014.
Load overglazed ware the same way you would load ce-
ramic glaze. Use stilts and make sure ware is not touching
other ware. Ware must be completely dry before firing.
13
A self-supporting cone fired to matu-
rity. Do not be concerned if the tip is
slightly higher or lower than shown.
A “puddled” over-fired cone.
Under-fired cone.
