Shifting Edges
The glaze longquan-iron-shino produces an opaque coppery matte surface with
black highlights, and a metallic sheen if thin.
The glaze longquan-iron-shino-PAlSi is derived from it by increasing the
alumina and silica with nearly the same
The ratio of alkali metals to alkaline earths in lonquan-iron-shino-PAlSi also
increased slightly,
The result in a translucent, near black tenmoku with a lustrous iridescent
surface film.
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
K2O 0.21
Al2O3 0.81
SiO2 3.56
molecular percent Silica 64.7%
K2O 0.22
Al2O3 0.89
SiO2 3.93
molecular percent Silica 66.01%
longquan-iron-shino-PAlSi is a less viscous glaze than longqun-iron-shino, but
only slightly so. The increased alkali metals
silica alumina ratio.
so it might seem that really all that happened is
that some CaO was replaced by Alkali metals, but, that change
does not account
for the entirety of the increase in Alumina.
Image of the glaze longquan-iron-shino
inside
outside
Image of the glaze longquan-iron-shino-PAlSi
inside
outside
oxidation firing to cone 10 in an electric kiln
Firing profiles
Up Fire profile
Down Fire Profile
Clay body is a grolleg porcelain from Tacoma Clay Art Center.
glaze compositions
Empirical Formula longquan-iron-shino :
Na2O 0.31
Li2O 0.19
CaO 0.24
MgO 0.05
Fe2O3 0.12
Empirical Formula longquan-iron-shino-PAlSi :
Na2O 0.32
Li2O 0.21
CaO 0.21
MgO 0.04
Fe2O3 0.13
Remarks
have more influence on the
viscosity of this glaze than higher Alumina and higher silica.