|As this is really
a fuse and slump combined, the firing is to a full fuse. We
VERY seldom fuse first and slump later, 99% of our firings are
done all in one on the mold to a full fuse temp of 1480F . Molds
are designed to withstand these temperatures. Using firing programs
that go up fast and come down fast, this is not ideal for the
molds OR the glass! Our recommended firing schedules are below.
Program 5 is ideal for float, and program 6 would be suitable
We use float glass
in the UV molds, cutting 4mm thick pieces for the base, enough
to pile up to be level with the top of the foot depression.
Usually 5 pieces. They are cut in 'steps' to follow the splay
on the base area. In other words, the first piece might be
160mm across, the second is cut 165 across, 3rd piece 170
etc. This stops the top glass from rolling into the space
that will be left between the foot pieces and the side of
the mold as they are fusing.The foot pieces are washed and
placed in the base. The top piece is best if is 5 or 6 mm
thick. Decorate as desired and place this on the mold.
Remember if the mold has steep sides, the
decoration pieces must be placed so they do not slide down
the sides of the bowl as it is slumping!
The top piece will slump down, and fuse to the base pieces
which have fused into a solid piece.
The UV range having the very heavy "foot"
of glass, need to be annealed at a slow rate to allow for
this thickness. No faster than 300F down to cold. Remember
there is at least 20 to 25 mm of glass in the base!
The soft glass - Bullseye, Spectrum, etc.
would have to have the top layer fused flat to make 6mm thickness
before then stacking the base of the mold, and firing again
to fuse and slump the top to the base. This might
have to be watched to judge the correct temperature, as the
soft glass does behave differently depending on the color!
In the UV range, the UVSQR and the
UVRTRI have steeper sides that the others, so to achieve the
best with an applied design, a fused flat tile should be made
first to avoid the shift and "avalanching" that
could occur in the pattern pieces.
NOTES ON USE AND CARE OF DRAGON
GLASS SLUMPING MOLDS
Dragon Glass molds are made from refractory
clay, and so need to be treated with a certain amount of care.
Dragon Glass molds do not have to be ¡®burnt off¡¯ before using,
they are ready to use from the box.
When you receive your new mold, it needs
to be wiped over with a damp sponge to remove any dust from
the manufacturing process. This will ensure that the first
layer of mold release/kiln wash will adhere properly to the
The occasional high spot or depression can
be sanded smooth with a bisque file, nail file or fine sand
The molds can be dried in the kiln after
washing and coating with mold release.
For top loading glass kilns i.e., shallow
¡°coffin¡± type glass kilns with elements in the roof - dry
on a fast ramp with the lid vented approximately 3 cm (1?¡±)
until no more moisture is evident, around 250oC to 300oC (400oF)
Let kiln cool to around 180oC (350oF) before opening the lid
wide. This is to avoid ¡®shocking¡¯ the molds. Fast ramp should
be approx. 700oC per hour (1290oF) This applies to front loading
kilns as well.
All clay molds must not be crash cooled below
650 oC (1200F). IMPORTANT
When the kiln is in the down, or annealing
cycle, it should not be opened hotter than 280oC (535oF),
then can be opened 3 cm (1¡±), until glass can be handled without