Tony Hansen on wed 10 jul 96
>Michelle Campbell posted a ^5 MATTE Transparent back in Oct 95.
>I tested it over some iron oxide brush strokes on a buff stoneware.
>Here it is.
>1213P Calcium Matte Transparent
>Wollastonite 33.88
>Frit 3134 21.10
>Kaolin 45.01
The glaze posted was part of a series I did to produce a saturated
calcia matte glaze using wollastonite instead of whiting. Note you need
to split the kaolin with calcined kaolin. If you don't the glaze will
shrink too much and crack during drying, then crawl during firing. You
can make your own calcined kaolin by bisque firing a planter full of raw
kaolin. Remember to use 12% less calcined because of the LOI.
I also tried high alumina low silica and sure enough, that gives a matte
too, just like the textbooks say. However the best results came with
both high CaO and high Al2O3 as follows: (this is still under
development)
CALCIUM ALUMINA TRANSPARENT MATTE CONE 5-6
RECIPE AMT OXIDE FORM ANAL
------------------------------------------
WOLLASTONITE 30.00 CaO 0.90 19.35
FERRO FRIT 3134 21.50 MgO 0.01 0.10
KAOLIN 25.50 Na2O 0.10 2.29
CALCINED KAOLIN 19.00 TiO2 0.00 0.02
FLINT 4.00 B2O3 0.19 5.14
Al2O3 0.51 19.94
SiO2 2.29 52.95
Fe2O3 0.00 0.17
MnO 0.00 0.04
WEIGHT: 259.87 L.O.I 3.33
-----------------------------ooO-(_)-Ooo---------------------------
Tony Hansen, IMC, 134 UPLAND DRIVE, Medicine Hat, Alberta
T1A 3N7 Canada Phone:403-527-2826 FAX:527-7441 BBS:527-6074
email: thansen@mlc.awinc.com web: http://digitalfire.com/imc.html
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