Page
7
of
7
SECTION 4 - Firing Time
4.1 Influences on Firing Time
For kilns & kilns fitted with Non Indicating Control firing time depends upon many use factors
including the type of ware, the mass of the ware and the temperature which the
furnace is required
to operate at.
Once the operator has learned the heating time taken for the particular process for
which the kiln is being used, this time should be noted so that in future, the kiln can be checked to
observe that it is not taking an unusually long time to reach the set temperature- which could
indicate a problem with the kiln.
NOTE:
The firing time will vary slightly with variations in the mass of the load, but this is normal.
4.2 Firing Time - Influences on Firing Time
It is possible to set the firing rate to a speed that is faster than the
kiln
power
can
provide.
Therefore
it
is
important
to
learn what the kiln
is
capable
of
providing
particularly
at
the
very
end
of
the
firing
.
The maximum firing rate will be influenced by many factors including the type of ware,
the mass of the ware and the maximum temperature to which the kiln is required to operate.
Once the operator has learned the maximum heating rates and has the times, then the firing rate
can be set so that it is always controlling the kiln and so the firing time (for a particular setting
rate) from one firing to another will always be the same. The kiln can be checked to observe that it
is not taking an unusually long time
to
reach
the
set
temperature
-
which
could
indicate
a
problem
with
the kiln.
SECTION 5 - Suggested Firing Ramp Rates and Soaks.
Top Temp
Soak (
Sp3
)
Ramp Rate (
rr
)
Bisque
(Check Clay Recommendations)
980
o
C -
1000
o
C
10 mins
1
o
C –
1.6
o
C / min
Earthenware Glaze
(Check Glaze recommendations)
1080
o
C -
1100
o
C
15 - 30 mins
1.6
o
C
– 2.5
o
C /min
Stoneware / Porcelain
(Check Clay Recommendations)
1220
o
C -
1260
o
C
10 mins
1
o
C –
1.6
o
C / min
Stoneware / Porcelain Glaze
(Check Glaze recommendations)
1220
o
C
- 1260
o
C
0 - 15 mins
1.6
o
C
– 2.5
o
C /min