Apply more glass separator to areas where the coating flakes off or
cracks with use. Gently sandpaper the base and apply another coat.
Note:
Before applying a new coat of glass separator, remove
only enough of the old separator to smoothen the surface. It is
not necessary to remove all the separator.
Shelf paper, sold by art glass
suppliers, does the same thing as
shelf separator: It prevents the
glass from sticking to the kiln
base. The shelf paper is placed
between the glass and the kiln
base. But if you use glass separa-
tor, you do not need shelf paper.
Some brands of shelf paper
produce an odor. For this reason
we recommend only glass separa-
tor when working in a kitchen area.
Note:
Even if you use shelf paper, the kiln base still needs a
coating of glass separator.
Position the Kiln
Inside the Microwave
Firing the kiln on the mi-
crowave's food rotator tray
produces better heat distri-
bution inside the kiln. How-
ever, in some microwaves
the rotator tray jerks as it
turns, moving glass pieces
out of position. If this is a
problem with your micro-
wave, either use a different
microwave, or remove the
rotator tray and rollers from
the microwave. If you cannot
remove the rotator parts,
then turn the rotator tray upside-down, and place 3 of the ½" ceramic
posts that came with your kiln on the tray. If there is enough space, it
may also be possible to remove the tray and place the posts in the bot-
tom of the microwave near the rotator parts.
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9
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Shelf paper under the glass.
Removing the rotator tray and rollers.
Note:
Clean the rollers
and area under the ro-
tator tray for the
smoothest rotation.
Note:
Always position 3
- 1/2" posts under the
kiln inside the micro-
wave oven. The posts
prevent the kiln from
overheating the bot-
tom of the microwave.
The Firing Time
All microwave ovens fire differently. The firing time varies from one
microwave to the next, and a kiln that is still warm from a previous fir-
ing takes less time to fire than a cold kiln. A fluctuation in voltage can
also change the firing time.
Five minutes is the recommended minimum firing time. Use a re-
duced power setting on your microwave if it fires in less time than 5
minutes. This will lengthen the firing time to give you finer control.
See the microwave manual for instructions on reduced heat settings.
The easiest way to
fire the kiln is to fire a
glass piece in several
stages, visually check-
ing the glass at each
stage. Each time you
visually check the
glass, fire 30 - 60 sec-
onds longer until the glass has fused to your satisfaction. Start out
underfiring a test piece, and gradually add more firing time.
Note:
The glass begins to fuse during the last 30 seconds of
firing. This is why precise fusing is much easier with visual in-
spection of the glass.
Keep a detailed firing logbook to record the firing times for each
type of project. Write down the following:
Date
Type of microwave oven
Brand, color, and size of glass
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10
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Left to right: tack fuse, medium fuse, and full fuse.
Clean the rollers and track for the smoothest rota-
tion of the tray.
