Service manual

sive-coated mesh that allows residue to pass through. You
could also use coarse sandpaper. Removing the old coating
gives you a smooth surface to start with. Then recoat the
shelf using the following directions. (Both glass separator
and kiln wash will be referred to as “separator.”)
Caution: Keep separator away from the elements.
1 Mix the separator with water following the directions
on the bag. Stir.
2 Use a haik brush or a soft
paint brush to apply the
separator to the shelf.
(The haik brush is easier
to use because it lays
down a more even coat
-
ing.) Each time you dip
your brush into the sepa
-
rator mixture, swirl the
brush around the bottom
of the container. This is because the separator settles
quickly. Use two or three thin coats changing the di
-
rection of the brush stroke 90° with each coat.
3 Dry the shelf before firing. To speed drying, place the
shelf on 3 - ½” posts inside the kiln. Heat at full rate
to 300°F/148°C and hold for 15 - 30 minutes. Then
turn off the kiln and leave the shelf inside.
4 After the separator has dried and your shelf is cool,
you can smoothen the separator further by rubbing
your hand lightly over the shelf. The smoother the
separator, the smoother the back side of the glass.
A coat of glass separator will usually last several firings.
The lower the fusing temperature, the more firings you can
get from one application of separator.
Using Posts
Ceramic posts support ceramic fireclay shelves.
I
When firing glass, place 3 - ½” posts under the ceramic
shelf on the firebrick bottom. This aids air circulation
around the shelf.
I
You can fire two or more ceramic shelves in your Caldera.
When you load multiple shelves, use a slower firing rate.
This aids heat distribution.
I
Always fire glass on a shelf. Ceramics can be fired on the
brick bottom as well as on shelves.
Venting the Kiln
Some types of ware, such as
ceramics, contain impurities
that burn off during firing.
These impurities must be re
-
leased from the kiln at the begin
-
ning of the firing. Otherwise
they can affect the quality of the
ware. To vent the kiln, place a ½”
post under the top.
Glass Fusing &
Slumping
You will probably fire mostly stained glass, but you can
also fire standard float (window) glass. Some types of float
glass devitrify (form a dull, frosty surface) when fused.
Caution: Never fire tempered glass. It could ex
-
plode if heated inside a kiln.
Basic Glass Tools
Reservoir Glass Cutter uses a reservoir of oil to lu
-
bricate the cutter wheel.
Running Pliers are for cutting large pieces of glass.
Breaking Pliers are for cutting small strips.
Grozing Pliers shape the glass by chipping away the
edges. They are often used when the score line doesn’t break
clean. Note that rough edges will become smooth when fired
to fusing temperature.
How to Cut Glass
Note: IMPORTANT! Wear safety glasses when
cutting or chipping glass.
1 Lay the glass on a clean surface. Mark off the cut with
a grease pencil or felt-tip pen. A small mark on each
end of the glass will do. Lay a wooden straight edge
over the glass and line it up with the marks you just
made.
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