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glaze test for saffire blue, cone 6, ox.and revision by ron roy,

updated mon 11 feb 02


Alisa og Claus Clausen on sun 10 feb 02

cone 6, ox.

Glaze test for: Saffire Blue, cone 6, ox.

Credited to:

All tests fired on white, iron flecked, mid-range stoneware.
Fired to cone 6 (1220c) in oxidation.

Firing ramp:
100c (212f) per hour to 600c (1112f)
150c (302f) per hour to 1100c (2012f)
100c per hour to 1220c (2228f)
15 - 30 minute soak depending on matts and glosses used.
cool down 100c per hour to 900c.
Natural cool down to 150c (approximately 15 hours)

25.5 EPK
42.6 Frit 3134
25.5 Custer Spar
15 Silica

4.3 Rutile
2.1 Cobalt oxide

All raw materials measured up or down to nearest whole decimal.
Oxides used on percent basis to a 100 gram batch of glaze.

Forshammer feldspar for Custer.

Resulted in:
Well covering light blue gloss, breaking darker blue with slightly greenish
cast. A lot of movement in glaze, but stayed where glazed. The thickest
areas are light to medium cornflower blue and the thinnest areas are dark
greenish in color.

Saffire Blue, revised by Ron Roy

37 Frit 3134
26 EPK
17 Flint
4 Strontium Carbonate
16 Custer Spar

2.5 Cobalt Carbonate
4.5 Rutile

Forshammer Feldspar or Custer

Resulted in:
a dark glue gloss that ran off the test tile.
Have to retest.

Regards from Alisa in Denmark