The Glaze Between
A line blend connecting the two glazes satIron_mashiko_neph_Imerys and
satIron_Alex_Z30_PPSi
satIron_Alex_Z30_PPSi is a capricious glaze, balanced between a full gloss
with scattered micro-crystals,
Which face satIron_Alex_Z30_PPSi shows depends somewhat on firing temperature,
but mostly on glaze application
No line blend, dart throwing time. It was the inlay on the
vase , with its bright coppery band surrounding
satIron_mashiko_neph_Imerys is a semi-matte saturated iron glaze with a
metallic sheen and contrasting
alex_mashiko_Imerys by contrast is a full gloss, essentially untextured.
Images are shown of the end members satIron_mashiko_neph_Imerys, and
satIron_Alex_Z30_PPSi in both
The design on the plate and vase, which is not addressed in this analysis, is
created by adhering a mask and then
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 50 min hold at 1750 deg F
50 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 0.08
Al2O3 0.61
SiO2 4.03
molecular percent Silica 66.7%
K2O 0.08
Al2O3 0.66
SiO2 3.69
molecular percent Silica 67.4%
K2O 0.08
Al2O3 0.62
SiO2 3.95
molecular percent Silica 66.2%
displayed a surprise glaze, alex_mashiko_Imerys,
with little resemblance to either end. This glaze is located near the
left member, satIron_mashiko_neph_Imerys. Its composed of four parts
satIron_mashiko_neph_Imerys
and one part satIron_Alex_Z30_PPSi.
and a micro-crystalline matte with a cellular
structure, whose glossy substrate manages only to peek through sporatically.
thickness. It is therefore not altogether
surprising that mixing it with another glaze produces unexpected results.
the inlay that
instigated this exploration. I noted that the metallic band seemed
brighter
closest to the inlay, and therefore chose a point on the line closer to
satIron_mashiko_neph_Imerys.
micro-crystals. satIron_Alex_Z30_PPSi also
features an array of semi-matte microcrystals.
its forms; and of the blended glaze,
alex_mashiko_Imerys.
applying the main glaze. After
drying, the mask is removed and the open area filled in with a second glaze.
Image of the left member satIron_mashiko_neph_Imerys
plate ~10 inches in diameter
Image of the right member satIron_Alex_Z30_PPSi
vase ~6 inches high
small section of a larger piece to show glaze
Image of the glaze alex_mashiko_Imerys
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 satIron_mashiko_neph_Imerys :
Na2O 0.11
Li2O 0.28
CaO 0.51
MgO 0.02
Fe2O3 0.25
P2O5 0.15
Empirical Formula satIron_Alex_Z30_PPSi :
Na2O 0.35
Li2O 0.17
CaO 0.25
MgO 0.15
Fe2O3 0.10
P2O5 0.03
Empirical Formula alex_mashiko_Imerys :
Na2O 0.16
Li2O 0.24
CaO 0.46
MgO 0.06
Fe2O3 0.26
P2O5 0.13