GA6A Alberta Slip Base comparison using Frit 3134, 3149, 3195

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These columns compare the original Alberta Slip cone 6 base (using Frit 3134) with versions using Frits 3249 and 3195 (which have a lower thermal expansion and produce a better glass).


Original Alberta Slip Base Glaze Cone 6

Code #

GA6-A

Materials Amt
Alberta Slip 40.000
Alberta Slip 1000F Roasted 40.000
Ferro Frit 3134 20.000

Total:100.00

Auto Unity Formula

CaO 0.48
MgO 0.24
K2O 0.09
Na2O 0.19
(KNaO) 0.28
B2O3 0.20
Al2O3 0.39
SiO2 2.70
Fe2O3 0.07

Ratios

Si:Al: 7.0:1
SiB:Al: 7.5:1
R2O:RO: 0.3:0.7

Expansion

7.6

LOI

4.9

Notes

*The long-time cone 6 base recipe for Alberta Slip. To this are added colorants, opacifiers and variegators to create other glazes.

Although other Frits can be used (e.g. 3195, 3249), this version (having Frit 3134) is the only one that produces rutile blues in the cool-and-soak firing schedule. This is likely because this has a lower Al2O3 level (the extra alumina is likely preventing the crystallization of the TiO2 in the rutile). This is also the only version that crystallizes on cooling in slow cool firing (e.g. the C6DHSC schedule).

Pictures

MA6A Alberta Slip Base Glaze Cone 6 glaze cones

On M350 and M340

GR6A and GA6A at cone 5R

Ravenscrag and Alberta Slip cone 6 bases. On buff burning body.

GA6A Alberta Slip base using Frit 3124, 3249 and 3195

The body is dark brown burning Plainsman M390 (cone 6). The amber colored glaze is 80% Alberta Slip (raw:calcine mix) with 20% of each frit. The white engobe on the inside of two of the mugs is L3954A (those mugs are glazed inside using transparent G2926B). The Alberta Slip amber gloss glaze produces an ultra-gloss surface of high quality on mugs 2 and 3 (Frit 3249 and 3195). On the outside we see it this glaze on the white slip until midway down, then on the bare red clay. The amber glaze on the first mug (with Frit 3124) has a pebbly surface that is not working nearly as well. These mugs are fired using a drop-and-soak firing schedule.

GA6-A Alberta Slip base crazes on P300

Fired in a cool-and-soak firing. It is better to use GA6-B (which employ Frit 3195 instead of Frit 3134).

MA6A plus 4% rutile at cone 6

Made by Joe Schmidt

Melted glaze for thermal expansion test has bubbled

GA6-A glaze with four frits (flow tests)

Four frits in GA6-A at cone 6

Frit 3195 (top left), 3134 (top right) 3214 (bottom left), 3249. 10 gram melt balls.

Alberta Slip on P300 with Frits 3134, 3124, 3249, 3195

This porcelain can be difficult to fit glazes to because it has a lower-than-normal silica content. Each of these test samples was thermal shock tested: 300F to ice water. Frit 3134 version (top left) crazing. 3124 slight crazing (top right). 3249 and 3195 (bottom) are uncrazed. 3134 version has the cleanest surface but 3195 is close behind. These were not slow cooled or drop-soaked during firing so they are all transparent.

Typecodes

ST-Untitled typecode

Alternate Code Number:GA6-A

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Original Alberta Slip Base Glaze Cone 6" id="70758" key="bfp5STNe" date="2021-04-20" typecodes="ST" codenum="GA6-A" picturebasename=""> <recipelines> <recipeline material="Alberta Slip" amount="40.000" tolerance=""/> <recipeline material="Alberta Slip 1000F Roasted" amount="40.000" tolerance=""/> <recipeline material="Ferro Frit 3134" amount="20.000" tolerance=""/> </recipelines> </recipe> </recipes>

Born: 2007-03-09, Modified: 2021-04-20 12:56:21

Alberta Slip Base Using Frit 3195

Code #

GA6-B

Materials Amt
Alberta Slip 1000F Roasted 40.000
Alberta Slip 40.000
Ferro Frit 3195 20.000

Total:100.00

Auto Unity Formula

CaO 0.45
MgO 0.28
K2O 0.11
Na2O 0.17
(KNaO) 0.27
TiO2 0.01
B2O3 0.23
Al2O3 0.51
SiO2 3.15
Fe2O3 0.08

Ratios

Si:Al: 6.1:1
SiB:Al: 6.6:1
R2O:RO: 0.3:0.7

Expansion

7.2

LOI

4.9

Notes

*An alternative recipe to GA6-A (this uses Ferro Frit 3195 instead of 3134). It fires to a more brilliant glossy surface.

This fires to a lower thermal expansion (by virtue of higher B2O3, Al2O3 and SiO2 levels) so will solve crazing issues on most bodies on which the GA6-A version crazes.

The chemistry in this is not compatible with the rutile blue version (see picture below).
This one also does not crystallize on slow cooling.

Pictures

GA6-A base using Frit 3249 and 3195 on buff body

The body is buff-burning Plainsman M340 (cone 6). The amber-colored glaze is 80% Alberta Slip (raw:calcine mix) with 20% of each frit. The inside of mug 1 is white engobed (L3954A) and with transparent over it (G2926B). The GA6-B glaze uses Frit 3195, covering mug 2 completely. Mug 1 uses low expansion frit 3249, it fires to the same brilliant gloss. But its low expansion could cause shivering on certain bodies. These mugs are fired using a drop-and-soak firing schedule yet no micro-crystals have grown as they would using the GA6-A recipe with Frit 3134.

GA6-A Alberta Slip Base with tin to prevent crystallization

Left: L3820 (casting M390) with Ravenscrag Floating blue outside and Alberta Slip GA6-A inside. That inside glaze has 1% added tin, it prevents the crystals that that normally grow when this is slow cooled using the C6DHSC firing schedule (like the inside glaze on the right). These crystals can be very beautiful on decorative surfaces, but if you want a clear amber glass they are not good. Right: M390 red-burning cone 6 stoneware (P6281) with Alberta Slip Rutile blue glaze outside and GA6-A liner (the slow cooling having crystallized it). Crystallization cannot also be prevented by using frit 3195 or 3249 instead.

GA6-B Alberta Slip base glaze does not crystallize

Right: The traditional Alberta Slip amber transparent has 80% Alberta Slip and 20% Ferro Frit 3134. It forms micro-crystals if the kiln is not cooled quickly. The Frit 3195 version on the left retains its brilliant transparent nature. The reason is the higher levels of Al2O3 (Frit 3134 has almost zero Al2O3).

M390 clay with white engobe inside

L3954A engobe inside, clear glazed inside (G2926B). Outside is GA6B base (uses Frit 3195 instead of 3134). The result is a glossier more defect free glass.

P300 with AlbertaSlip:Frit 3195 glaze fires crystal-free

This glaze produces a flawless results with a normal free-fall cool cycle. But that is not what this was. In this cone 6 firing the temperature was dropped from 2200F to 2100F, held for 30 minutes, then dropped slowly (300F/hr) all the way down to 1400F. In that firing schedule the standard GA6-A base recipe would be completely covered in iron silicate crystals.

M340 with L3954B engobe, GA6-B base glaze. Cone 6.

GA6-B base Alberta Slip glaze on M340. Cone 6.

GA6-B plus iron oxide

Top: GA6-B Bottom: Plus 1, 2, 3 and 4% iron oxide.

Alberta Slip as a Celadon at cone 6 and 10R

Left: Alberta Slip 80, Frit 3195 20. On Plainsman M370. Right: Alberta Slip/Ravenscrag Slip 50:50 mix. On Plainsman P700.

GA6-B Base does not make rutile blue

Left is the standard GA6-A with Frit 3134. GA6-B on the right has the rutile also, and was in the same firing, but the higher Al2O3 prevents its variegating action.

Typecodes

ST-Untitled typecode

Alternate Code Number:GA6-A

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Alberta Slip Base Using Frit 3195" id="143991" key="KpsdX8d1" date="2021-04-20" typecodes="ST" codenum="GA6-B" picturebasename=""> <recipelines> <recipeline material="Alberta Slip 1000F Roasted" amount="40.000" tolerance=""/> <recipeline material="Alberta Slip" amount="40.000" tolerance=""/> <recipeline material="Ferro Frit 3195" amount="20.000" tolerance=""/> </recipelines> </recipe> </recipes>

Born: 2007-03-09, Modified: 2021-04-20 12:48:32

Alberta Slip Base Using Frit 3249

Code #

L3500E

Materials Amt
Alberta Slip 40.000 21.05%
Ferro Frit 3249 20.000 10.53%
Alberta Slip 1000F Roasted 40.000 21.05%
Water 90.000 47.37%

Total:190.00

Auto Unity Formula

CaO 0.33
MgO 0.47
K2O 0.10
Na2O 0.10
(KNaO) 0.20
B2O3 0.28
Al2O3 0.50
SiO2 2.93
Fe2O3 0.08

Ratios

Si:Al: 5.9:1
SiB:Al: 6.4:1
R2O:RO: 0.2:0.8

Expansion

6.5

LOI

2.6

Cost

0.00 per kg

Notes

*This is part of a program to compare the results of fluxing Alberta Slip for cone 6 using 4 different frits (3134, 3124, 3195 and 3249).

Frit 3249, used here, is a low expansion frit, it reduces the thermal expansion of the Alberta Slip base GA6-A (from 7.6 to 6.5), such that it works well on even P300 porcelain.

Even though this recipe calculates to a low Si:Al ratio and a very high MgO level (both indicative of a matte glaze), this one fires ultra glossy.

We generally add 2% iron oxide to darken the color.

2700 water, 3000 dry gives 1.43

Pictures

GA6-A base using Frit 3249 and 3195 on buff body

The body is buff-burning Plainsman M340 (cone 6). The amber-colored glaze is 80% Alberta Slip (raw:calcine mix) with 20% of each frit. The inside of mug 1 is white engobed (L3954A) and with transparent over it (G2926B). The GA6-B glaze uses Frit 3195, covering mug 2 completely. Mug 1 uses low expansion frit 3249, it fires to the same brilliant gloss. But its low expansion could cause shivering on certain bodies. These mugs are fired using a drop-and-soak firing schedule yet no micro-crystals have grown as they would using the GA6-A recipe with Frit 3134.

P300 and M370 mugs with GA6A Alberta Slip (using Frit 3249)

Rather than the normal 80:20 AlbertaSlip:Frit3134 recipe, this one substitutes Frit 3249 (super low expansion). The glaze is less runny and even glossier. These are fired at cone 6 in a cool-and-soak firing. They survived boiling water:ice water tests without crazing. The finish is dazzling, a brilliant amber glass with no defects and perfectly even coverage. Of course, the iron in the glass prevents the colors of the blue underglaze from showing through. But the black is great.

GA6A base using Frit 3249 - P300 cone 6

Surface is flawless. Drop and soak firing.

P6850 M390 with L3500E AltaSlip 3249 base inside

2% iron has been added, making the color much deeper. On this dark clay (inside) it fires almost black. GA6-C outside, firing is slow cool.

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Alberta Slip Base Using Frit 3249" id="113315" key="c6PCNSrk" date="2021-04-20" codenum="L3500E"> <recipelines> <recipeline material="Alberta Slip" amount="40.000" tolerance=""/> <recipeline material="Ferro Frit 3249" amount="20.000" tolerance=""/> <recipeline material="Alberta Slip 1000F Roasted" amount="40.000" tolerance=""/> <recipeline material="Water" amount="90.000" tolerance=""/> </recipelines> </recipe> </recipes>

Born: 2006-08-30, Modified: 2021-04-20 14:30:03