leaves on saturated iron glaze
Surface active glazes are those glazes where the interaction at the surface is
an integral part of the evolution
The first glaze longquan-iron-shino-Z3N-0 as seen
here it has micro-crystals which form
The second glaze, satIron_ZG_Z3N_EPK, develops leopard spots, is derived from
the glaze
satIron_ZG_Z3N
Rae Graden of Tacoma Clay Art Center remarked that kaolin enters the melt much
more readily than does mica.
Compared to its origin satIron_ZG_Z3N, it is a bit higher in silica, and the
K2O:Na2O ratio has changed.
plate is ~ 7 inches in diameter.
plate is ~ 7 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 1850 deg F then a 2 hour hold at 1850 deg F
300 deg F an hour to 1750 deg F then a 1 hour hold at 1750 deg F
300 deg F an hour to 1700 deg F then a 3 hour hold at 1700 deg F
25 deg F an hour to 1650 deg F then a one hour hold at 1650 deg F
K2O 0.13
Al2O3 0.88
SiO2 3.49
molecular percent Silica 62.2%
K2O 0.13
Al2O3 0.73
SiO2 3.65
molecular percent Silica 64%
K2O 0.43
Al2O3 0.54
SiO2 3.33
molecular percent Silica 48%
A leaf is softened by soaking in water laced with trisodium phosphate. After
the pot is glazed, the leaf is pressed
of the glaze. Here are leaf prints on
two surface active glazes. It was expected that an additional layer atop
the glaze, which is the leaf wash, together with the surface activity of the
glaze will combine to
texture the leaf print.
on the surface of the glaze.
The glaze application on this plate was thick, resulting in this textured
surface.
which does not mature at cone 10, as a result of
containing mica.
Rae suggested that I replace the mica with EPK
Kaolin, then replace the missing alkali metals with Na2O.
satIron_ZG_Z3N_EPK
is the direct result of that suggestion, which had seemed strange to
me, yet as seen here,
it worked spectacularly well.
Image of the plate with glaze longquan-iron-shino-Z3N-0 and leaf wash
leaf_Z3K.
Image of the plate with glaze satIron_ZG_Z3N_EPK and leaf wash leaf_Z3K.
oxidation firing to cone 10 in an electric kiln
Firing profiles
Up Fire profile
Down Fire Profile
Clay body is a grolleg porcelain from Clay Art Center in Tacoma, WA.
glaze compositions
Empirical Formula longquan-iron-shino-Z3N-0 :
Na2O 0.47
CaO 0.28
MgO 0.12
Fe2O3 0.16
P2O5 0.08
Empirical Formula satIron_ZG_Z3N_EPK:
Na2O 0.57
CaO 0.28
MgO 0.02
Fe2O3 0.24
P2O5 0.07
Empirical Formulae of leaf wash glaze leaf_Z3K:
Na2O 0.53
CaO 0.04
P2O5 0.15
into the glaze. When the glaze
dries, a swatch of plate including the leaf is coated with wax. When the wax
is dry, the leaf is removed and the indentations in the glaze are coated
with a very thin layer of an
underfired glaze.