Ravenscrag Slip cone 6 base glaze using various frits

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Ravenscrag Original Clear Base

Code #

GR6-A

Materials Amt
Ravenscrag Slip 50.000
Ferro Frit 3134 20.000
*Ravenscrag Slip Roast 1000F 30.000

Total:100.00

Auto Unity Formula

CaO 0.68
MgO 0.09
K2O 0.07
Na2O 0.16
(KNaO) 0.22
TiO2 0.01
B2O3 0.28
Al2O3 0.28
SiO2 2.84
Fe2O3 0.01

Ratios

Si:Al: 10.1:1
SiB:Al: 11.1:1
R2O:RO: 0.2:0.8

Expansion

7.3

LOI

4.4

Notes

*Ravenscrag Slip is produced by Plainsman Clays. I melts, at 100%, to a silky transparent at cone 10R. A 20% frit addition melts it for use at cone 6 oxidation.

Tranitionally we have used Ferro Frit 3134, but have also experimented with other frits (e.g. 3249, F-524).

Ravenscrag Slip suspends well in water and normally one can just mix it 80:20 with a frit. But we have found that this can crack during drying. Thus we use a 50:30 mix of raw:roast material (more information on the page at PlainsmanClays.com). However, if you wish to add some CMC Gum, then the 50:30 mix is not needed (although it will dry slower and be more difficult to get an even layer (without drips).

This can be used as a base recipe. You can add opacifiers, colorants and variegators to produce all manner of visual effects. This differs from a regular clear glaze made from industrial minerals in that the fired appearance is more organic, less sterile.

Pictures

GR6-A Ravenscrag Clear cone 6

On M370, M340 and M390.

GR6-A Ravenscrag white cone 6

Adds 10% zirocpax to the GR6-A recipe. On M370, M340 and M390.

G2936 vs GR6-A - Cone 6 on M370

G2936 vs GR6-A - Cone 6 on M370

On M370

Alternate Code Number:GR6-A

Variations

1 - Pink

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Ravenscrag Original Clear Base" id="56548" key="QEirPpWR" date="2021-09-14" codenum="GR6-A"> <recipelines> <recipeline material="Ravenscrag Slip" amount="50.000" tolerance=""/> <recipeline material="Ferro Frit 3134" amount="20.000" tolerance=""/> <recipeline material="Ravenscrag Slip Roast 1000F" amount="30.000" tolerance=""/> </recipelines> </recipe> </recipes>

Born: 2014-03-03, Modified: 2021-09-14 13:52:45

Ravenscrag with 20% Frit 3249

Code #

G2936

Materials Amt
Ravenscrag Slip 80.000
Frit 3249 20.000

Total:100.00

Auto Unity Formula

CaO 0.55
MgO 0.33
K2O 0.09
Na2O 0.02
(KNaO) 0.11
TiO2 0.01
B2O3 0.29
Al2O3 0.44
SiO2 3.39
Fe2O3 0.01

Ratios

Si:Al: 7.7:1
SiB:Al: 8.4:1
R2O:RO: 0.1:0.9

Expansion

5.9

LOI

7.0

Cost

2.20 per kg

Notes

*This frit appears to produce slightly better results than Frit 3134 (less dimples, surface defects). We used the PLC6DS firing schedule.

Since this is not a roast:raw mix it would be best to use an appropriate CMC gum solution:water mixture.

Pictures

G2936A - Ravenscrag with 20% Frit 3249

Cone 6 PLC6DS firing. Excellent results, no pinholes, bubbles as can happen with frit 3134.

G2936 clear vs G2936A white - Cone 6 PLC6DS firing

G2936 vs G2936A - Cone 6 PLC6DS firing

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Ravenscrag with 20% Frit 3249" id="57080" key="Nzc3kCuL" date="2021-09-14" codenum="G2936" picturebasename=""> <recipelines> <recipeline material="Ravenscrag Slip" amount="80.000" tolerance=""/> <recipeline material="Frit 3249" amount="20.000" tolerance=""/> </recipelines> </recipe> </recipes>

Born: 2014-03-17, Modified: 2021-09-14 14:04:03

Ravenscrag +20% Frit 3249 +Zircon

Code #

G2936A

Materials Amt
Ravenscrag Slip 80.000
Frit 3249 20.000
Additions Amt
Zircopax 10.000

Total:110.00

Notes

*We also incorporated some gum solution, this worked well to eliminate cracking on drying (thus no roast:raw mix was needed).

The white variation of the GR6-A glaze can be quite striking (compared to the "toilet bowl" appearances of other whites. This version is likely to produce a more defect-free surface. And this frit, although more expensive, reduced the thermal expansion, that should eliminate any issues with crazing on just about any clay body.

Pictures

G2936 clear vs G2936A white - Cone 6 PLC6DS firing

G2936A - Cone 6 PLC6DS firing

On M370, M340, M390 - Excellent results on all of them!

G2936 vs G2936A - Cone 6 PLC6DS firing

Tin opacified g2926b vs g2936a on black engobe

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Ravenscrag +20% Frit 3249 +Zircon" id="205853" key="bz2wjhFH" date="2021-09-19" codenum="G2936A" picturebasename=""> <recipelines> <recipeline material="Ravenscrag Slip" amount="80.000" tolerance=""/> <recipeline material="Frit 3249" amount="20.000" tolerance=""/> <recipeline material="Zircopax" amount="10.000" added="true"/> </recipelines> </recipe> </recipes>

Born: 2014-03-17, Modified: 2021-09-19 14:41:08

Ravenscrag Slip Clear Cone 6 Using 3D

Code #

G3898

Materials Amt
PR#3 D 30.000
Ferro Frit 3134 27.000
*PR#3 D Roast 29.000
Dolomite 4.000
Whiting 9.000
Additions Amt
Zircopax 2.000

Total:101.00

Auto Unity Formula

CaO 0.72
MgO 0.09
K2O 0.03
Na2O 0.16
(KNaO) 0.19
B2O3 0.31
Al2O3 0.19
SiO2 2.00
ZrO2 0.04

Ratios

Si:Al: 10.8:1
SiB:Al: 12.5:1
R2O:RO: 0.2:0.8

Expansion

7.8

LOI

7.9

Cost

0.10 per kg

Notes

*A cone 6 base made directly from Plainsman 3D (from which Ravenscrag Slip is made). This achieves a higher percentage of it than GR6-A. Al2O3 and SiO2 are a little higher, but the extra frit should melt them.

This has a lower thermal expansion.
Mixed 1020 powder, 810 water to get a slurry that is a little too viscous.

Pictures

GA6-A vs G3898 flow test - Cone 6

Alternate Code Number:GR6-A

Testdata

LDW - LOI/Density/Water Content

WWGT DWGT H2O LOI DENS
1 8.56 4.83 43.6%

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Ravenscrag Slip Clear Cone 6 Using 3D" id="179024" key="bm6QwSkd" date="2021-09-14" codenum="G3898"> <recipelines> <recipeline material="PR#3 D" amount="30.000" tolerance=""/> <recipeline material="Ferro Frit 3134" amount="27.000" tolerance=""/> <recipeline material="PR#3 D Roast" amount="29.000" tolerance=""/> <recipeline material="Dolomite" amount="4.000" tolerance=""/> <recipeline material="Whiting" amount="9.000" tolerance=""/> <recipeline material="Zircopax" amount="2.000" added="true"/> </recipelines> </recipe> </recipes>

Born: 2014-03-03, Modified: 2021-09-14 14:00:10