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woodfire blue temmoku.

updated sun 31 oct 99


Stephen Grimmer on sat 30 oct 99

I needed a liner for some greenware vases to go in our wood burner, and
calculated the following to (low in Si&Al if you include iron in the

Redart Liner
REDART.............. 56.00 53.85%
WHITING............. 22.00 21.15%
FLINT............... 22.00 21.15%
IRON OXIDE RED...... 4.00 3.85%

CaO 0.70* 14.60%
MgO 0.07* 0.98%
K2O 0.07* 2.56%
Na2O 0.01* 0.23%
TiO2 0.02 0.67%
Al2O3 0.25 9.56%
P2O5 0.00 0.13%
SiO2 2.82 62.59%
Fe2O3 0.15* 8.67%

Cost/kg 0.73
Si:Al 11.11
SiB:Al 11.11
Expan 7.10

In a C10 reduction fire, this is a nice temmoku. On several of the jars in
the firebox of the wood kiln, however, the rims are covered with a vivid,
matte, indigo blue, flowing into the green and yellow ash on the sides. It's
as if someone applied a wash of cobalt to the rims. The kiln was fired to
C11/12 in the fire box over a period of five days with about 95% white oak
and 5% pine. Most of the wood is slab with plenty of bark, generally
well-seasoned, though we did run into a patch of wetter-than-ideal wood that
was stoked for about 12 hours. Could this be the result of fabled hydrogen
reduction? Is the phosphorus in the ash doing something?

curious-er and curiouser,

Steve Grimmer
Bowling Green State University
Bowling Green, OH