Phosphorus
The high phosphorus glaze satIron_ZT_Mashiko is shown on a mug here:
Here I show a modification of this glaze with higher magnesium.
As the source of phosphorus is bone ash, higher magnesium with similar phosphorus reqires similar calcium, and thus less alkali metals. To partially compensate lithium is increased.
cone 10 oxidation
Firing profile
Up Fire profile
150 deg F an hour to 250 deg F
400 deg F an hour to 2050 deg F
120 deg F an hour to 2250 deg F
60 deg F an hour to 2310 deg F with a hold of 20 minutes at 2310 deg F
Down Fire Profile
A half hour hold at 1750 deg F
A three hour hold at 1700 deg F
slow downfire at 25 deg F an hour in the interval 1700 deg F to 1650 deg F
A one hour hold at 1650 deg F
The cones show this as a cone 10 firing.
K2O .08
Al2O3 .6
SiO2 4.37
molecular percent Silica 69
K2O .04
Al2O3 .6
SiO2 4.32
molecular percent Silica 68%
Note that the higher Magnesia glaze, satIron_ZT_Mashiko_1E_0 compared to
satIron_ZT_Mashiko is satin matte rather than full gloss, Clay body is a grolleg porcelain from Tacoma Clay Art Center.
glaze compositions
Empirical Formula glaze satIron_ZT_Mashiko :
Na2O .08
Li2O .17
CaO .49
MgO .18
Fe2O3 .23
P2O5 .16
Empirical Formula glaze satIron_ZT_Mashiko_1E_0 :
Na2O .03
Li2O .19
CaO .51
MgO .23
Fe2O3 .24
P2O5 .17
glaze satIron_ZT_Mashiko
glaze satIron_ZT_Mashiko_1E_0
bowl ~ 4 inches in diameter
Remarks
and red-orange
rather than yellow-orange.