Firing Effects
A glaze which shifts from iron red to a variegated orange and black with
an additional hold
Several other glazes were noticeably affected by that retarded downfire near
peak temperature. I show four of them.
The first firing drops from top temperature to 1750 deg F at 300 deg F an
hour. This rate of temperature
The second firing drops only to 2210 deg F at that rapid rate of 300 deg F an
hour. It then has a one hour hold,
The primary difference between these two firings is that slow cooling at a
temperature near the top,
Both firings have holds at 1750 deg F, and 1700 deg F. The difference in the
lengths of these holds will effect the
bowl is ~ 4 inches in diameter.
bowl is ~ 4 inches in diameter.
vase is ~11 inches high.
The design is created by adhering a mask and then applying the main
glaze. After drying, the mask is removed
bowl is ~ 4 inches in diameter.
bowl is ~ 4 inches in diameter.
bowl is ~ 4 inches in diameter.
bowl is ~ 4 inches in diameter.
bowl is ~ 4 inches in diameter.
150 deg F an hour to 250 deg F
400 deg F an hour to 1800 deg F
300 deg F an hour to 2050 deg F
120 deg F an hour to 2310 deg F with a hold of 20 minutes at 2310 deg F
300 deg F an hour to 1750 deg F then a half hour hold at 1750 deg F
300 deg F an hour to 1700 deg F then a Three hour hold at 1700 deg F
25 deg F an hour to 1650 deg F then a one hour hold at 1650 deg F
150 deg F an hour to 250 deg F
400 deg F an hour to 2050 deg F then a hold of 20 min
120 deg F an hour to 2310 deg F with a hold of 20 minutes at 2310 deg F
300 deg F an hour to 2210 deg F then a one hour hold at 2210 deg F
80 deg F an hour to 1900 deg F
300 deg F an hour to 1750 deg F then a half hour hold at 1750 deg F
300 deg F an hour to 1700 deg F then a Two hour hold at 1700 deg F
300 deg F an hour to 1600 deg F then a Two hour hold at 1600 deg F
K2O 0.11
Al2O3 0.71
SiO2 4.27
molecular percent Silica 69%
K2O 0.08
Al2O3 0.65
SiO2 3
molecular percent Silica 63.5%
K2O 0.22
Al2O3 0.98
SiO2 4
molecular percent Silica 65.3%
K2O 0.13
Al2O3 0.97
SiO2 3.5
molecular percent Silica 62.4%
on the way down near top temperature is seen
here .
drop is an approximation to "dropping like a
stone," yet slow enough that the multiple zones in the kiln can maintain
nearly the same temperature.
then drops to 1900 deg F at only 80
deg F an hour.
but not so high that a higher cone would thereby be
reached.
size of crystals formed, but not their
formation.
Image of the glaze longquan_iron_mashiko_0 in Firing 1
inside
outside
Image of the glaze longquan_iron_mashiko_0 in Firing 2
inside
outside
Image of the glaze satIron_Alex_Puah in Firing 1
and the open area filled in with a
second glaze, using a bulb syringe with a needle applicator.
Image of the glaze satIron_Alex_Puah in Firing 2
inside
outside
Image of the glaze longquan-iron-shino-Z37 in Firing 1
inside
outside
Image of the glaze longquan-iron-shino-Z37 in Firing 2
inside
outside
Image of the glaze longquan-iron-shino-Z38-1 in Firing 1
inside
outside
Image of the glaze longquan-iron-shino-Z38-1 in Firing 2
inside
outside
oxidation firing to cone 10 in an electric kiln
Firing profile 1
Up Fire profile
Down Fire Profile
Firing profile 2
Up Fire profile
Down Fire Profile
Clay body is a grolleg porcelain from Tacoma Clay Art Center.
glaze compositions
Empirical Formula longquan_iron_mashiko_0 :
Na2O 0.45
Li2O 0.15
CaO 0.11
MgO 0.18
Fe2O3 0.19
Empirical Formula satIron_Alex_Puah :
Na2O 0.34
Li2O 0.18
CaO 0.22
MgO 0.18
Fe2O3 0.07
P2O5 0.03
Empirical Formula longquan-iron-shino-Z37 :
Na2O 0.33
Li2O 0.22
CaO 0.18
MgO 0.05
Fe2O3 0.15
Empirical Formula longquan-iron-shino-Z38-1 :
Na2O 0.41
Li2O 0.20
CaO 0.21
MgO 0.05
Fe2O3 0.14