Fix High Calcium SemiMatte crawling with #6 Tile Kaolin

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High Calcium Semimatte 1 (Mastering Glazes)

From page 86 of Mastering Glazes book

Code #

G4615A

Materials Amt
Ferro Frit 3195 20.000
Wollastonite 29.000
Nepheline Syenite 4.000
EPK 30.000
Silica 17.000

Total:100.00

Auto Unity Formula

CaO 0.91
Na2O 0.08
(KNaO) 0.08
B2O3 0.20
Al2O3 0.44
SiO2 3.00

Ratios

Si:Al: 6.8:1
SiB:Al: 7.2:1
R2O:RO: 0.1:0.9

Expansion

6.5 (Molar:6.6)

LOI

4.5

Cost

0.00 per kg

Notes

Pictures

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="High Calcium Semimatte 1 (Mastering Glazes)" keywords="From page 86 of Mastering Glazes book" id="283539" key="nf62rR6G" date="2026-10-16" codenum="G4615A"> <recipelines> <recipeline material="Ferro Frit 3195" amount="20.000"/> <recipeline material="Wollastonite" amount="29.000"/> <recipeline material="Nepheline Syenite" amount="4.000"/> <recipeline material="EPK" amount="30.000"/> <recipeline material="Silica" amount="17.000"/> </recipelines> </recipe> </recipes>

Born: 2026-01-04, Modified: 2026-10-16 16:26:18

High Calcium Semimatte 1 with #6 Tile kaolin

From page 86 of Mastering Glazes book

Code #

G4615B

Materials Amt
Ferro Frit 3195 20.000
Wollastonite 29.000
Nepheline Syenite 4.000
#6 Tile Kaolin 30.000
Silica 17.000

Total:100.00

Auto Unity Formula

CaO 0.91
Na2O 0.08
(KNaO) 0.08
TiO2 0.02
B2O3 0.20
Al2O3 0.45
SiO2 2.98

Ratios

Si:Al: 6.6:1
SiB:Al: 7.1:1
R2O:RO: 0.1:0.9

Expansion

6.5 (Molar:6.6)

LOI

4.1

Cost

0.00 per kg

Notes

#6 Tile kaolin is being substituted for EPK. This is resulting in crawling because this new kaolin is so much more plastic (thus it shrinks more on drying, creating cracks that become crawling during firing).

The impact on the chemistry of the glaze appears minimal.

Pictures

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="High Calcium Semimatte 1 with #6 Tile kaolin" keywords="From page 86 of Mastering Glazes book" id="296710" key="ZXhNYSNb" date="2026-10-16" codenum="G4615B"> <recipelines> <recipeline material="Ferro Frit 3195" amount="20.000" tolerance=""/> <recipeline material="Wollastonite" amount="29.000" tolerance=""/> <recipeline material="Nepheline Syenite" amount="4.000" tolerance=""/> <recipeline material="#6 Tile Kaolin" amount="30.000" tolerance=""/> <recipeline material="Silica" amount="17.000" tolerance=""/> </recipelines> </recipe> </recipes>

Born: 2026-01-04, Modified: 2026-10-16 16:28:33

High Calcium Semimatte 1 with #6 Tile/Calcined kaolins

From page 86 of Mastering Glazes book

Code #

G4615C

Materials Amt
Ferro Frit 3195 20.000 20.41%
Wollastonite 29.000 29.59%
Nepheline Syenite 4.000 4.08%
#6 Tile Kaolin 18.000 18.37%
Silica 18.000 18.37%
Calcined Kaolin 9.000 9.18%

Total:98.00

Auto Unity Formula

CaO 0.91
Na2O 0.08
(KNaO) 0.08
B2O3 0.20
Al2O3 0.44
SiO2 3.02

Ratios

Si:Al: 6.9:1
SiB:Al: 7.4:1
R2O:RO: 0.1:0.9

Expansion

6.5 (Molar:6.6)

LOI

2.5

Cost

0.00 per kg

Notes

Pictures

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="High Calcium Semimatte 1 with #6 Tile/Calcined kaolins" keywords="From page 86 of Mastering Glazes book" id="296711" key="gc6SfFsE" date="2026-10-16" codenum="G4615C"> <recipelines> <recipeline material="Ferro Frit 3195" amount="20.000" tolerance=""/> <recipeline material="Wollastonite" amount="29.000" tolerance=""/> <recipeline material="Nepheline Syenite" amount="4.000" tolerance=""/> <recipeline material="#6 Tile Kaolin" amount="18.000" tolerance=""/> <recipeline material="Silica" amount="18.000" tolerance=""/> <recipeline material="Calcined Kaolin" amount="9.000"/> </recipelines> </recipe> </recipes>

Born: 2026-01-04, Modified: 2026-10-16 16:29:20

Edit

EPK

Status

Treated as an added material in recipes

Using the following chemistry from

EP Kaolin

Oxide Analysis Formula Mole%
CaO 0.18 0.01 0.28
MgO 0.10 0.01 0.22
K2O 0.33 0.01 0.30
Na2O 0.06 tr 0.08
TiO2 0.37 0.01 0.40
P2O5 0.24 tr 0.15
Al2O3 37.37 1.00 31.89
SiO2 45.75 2.07 66.25
Fe2O3 0.79 0.01 0.43

Volatiles

H2O 1.40
LOI 13.20
SO3 0.21

LOI

14.8%

Formula Weight

231.43

Calculated Thermal Expansion (?)

5.0

Ratios (?)

Si:Al Ratio:2.1:1

Alkali Ratio:0.4:0.6

Cost and Cost Units

2.36 per KG

Notes

Inventory Movements

None found.

Reference Material

Tile #6 Kaolin

Highly Plastic Fine Grained

Alternate Names

Tile 6, Tile#6 Kaolin, #6 Tile kaolin

CAS Number

1332-58-7

Oxide Analysis Formula Mole%
CaO 0.30 0.01 0.46
MgO 0.40 0.03 0.85
Na2O 0.10 tr 0.14
TiO2 1.40 0.05 1.50
Al2O3 38.19 1.00 31.98
SiO2 45.61 2.03 64.81
Fe2O3 0.50 0.01 0.27

Volatiles

LOI 13.50

LOI

13.5%

Formula Weight

231.04

Calculated Thermal Expansion (?)

5.0

Ratios (?)

Si:Al Ratio:2.0:1

Alkali Ratio:0.1:0.9

Cost and Cost Units

Can only be set in your own custom materials

Notes

#6 Tile is an air-floated highly plastic kaolin. It thus offers high green strength. No other kaolin we know of in the world even comes close to the plasticity of this material. A cone 10 porcelain can be made using a 50:25:25 recipe of this with silica and feldspar. With a small bentonite addition, bodies can be made that are plastic enough for wheel-throwing gigantic vessels. #6 tile is thus also good for suspending glazes. However, this material is relatively impermeable to water compared to other kaolins, it is thus the last choice for casting bodies.

#6 Tile kaolin fires to respectable whiteness and compares well with most other North American kaolins. It is an excellent example of one having properties that cannot be fully appreciated from numbers on a data sheet, it is only by getting your hands dirty that its properties will become truly evident.

#6 Tile kaolin has been available for many decades and the consistency has been excellent.

Particle size, % < 2 microns 60
325 mesh screen residue, % max 0.5
M.B.I. (meq/100g) 9.8
Specific Surface Area (sq-m/g) 20.0
pH, 20% solids 6.5
*The information given here is from their data sheet dated Jan 2013

Inventory Movements

Can only be set in your own custom materials