Manual Glass Kiln

agenttokeepthegrainsofenamelinplace.Allowtheenamel
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
shouldbefiredwithastiltevenifthepiecehasaplain
bottom.Useanenamelingforkor,iftherackissmall,
a 6” putty knife, toplace therack intothe kilnon top
of ½” ceramic posts.
Note: Firing the piece at enameling temperature
shouldtakeaboutthreeminutesandrequiresundi-
vided attention!
3 Lookatyourpieceevery15secondsbycrackingopen
thedoor.Removetherackwhenthecopperpieceap
-
pears arosy redand theenamel issmooth. Place the
rackonasteelpadorlargeceramickilnshelfandletit
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
whenexposed toheat.They
indicatewhenceramicware
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
mustbeslanted8°fromver
-
tical.Theywillnotbendac
-
curately if they are slanted
to the wrong angle.
Self-supporting large
coneshavethecorrectslant
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
pyrometriccones.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
firingspeedofimportantpieces,testfiresampleclaypieces.
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.