Alisa og Claus Clausen on sun 10 feb 02
Glaze test for: Stonehenge, cone 6, ox.
All tests fired on white, iron flecked, mid-range stoneware.
Fired to cone 6 (1220c) in oxidation.
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)
51.6 Soda Feldspar
8.6 Zinc ox.
1 Cobalt Carbonate
3 Granular Ilmenite
add after screening
All raw materials measured up or down to nearest whole decimal.
Oxides used on percent basis to a 100 gram batch of glaze.
1 gm. RIO for 3 gm.RIO for grounded Ilmenite.
Because Hamer and Hamer describes Ilmenite as Iron and Titanium Oxide, and
because Rutile is describes as natural Titanium oxide with up to 15% iron
oxide) The recipe calls for Rutile already.
A streaking and moving blue gloss. Where thinnest, the glaze is a dark
cobalt blue gloss. Where thickest, the glaze turns more to lighter, whitish
blue, with streaks and feathers. I would like to hear what the original
recipe result looks like. I did not expect such a blue glaze. Even though
the glaze moves a lot, it stayed exactly where glazed.
Regards from Alisa in Denmark