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Alberta Slip Lithium Brown Cone 6

Code: GA6-G
Modification Date: 2015-10-30 18:56:03
Member of Group: AS6

Plainsman Cone 6 Alberta Slip based glaze. It can be found among others at http://albertaslip.com.

MaterialAmountPercent
Alberta Slip40.036.4%
Alberta Slip Calcined35.031.8%
Ferro Frit 319521.019.1%
Lithium Carbonate5.04.5%
Alumina Hydrate5.04.5%
Additions
Tin Oxide4.03.6%
 110.00  

Firing Schedule

Rate (F)Temp (F)Hold (Min)Step
100220601
300173302
1082175153
1502075304

Notes

One of the most popular Albany Slip glazes was 11% lithium, 4% Tin and 85% Albany Slip. A portion of the Alberta Slip must be milled or the glaze will crack during drying.

This recipe reduces the lithium to reduce shivering problems (that were common with this) and it employs a frit to help melt the glaze. The surface is very smooth and variation in color with thickness is very good. The added alumina hydrate darkens the color and slightly dulls the very glossy nature of the recipe, you can leave it out if you want.

Visually, this glaze works very well on porcelain showing variegated effects even on smooth surfaces, especially where very thinnly applied. However it crazes on porcelains, please use the alternate lithium brown recipe.

Alberta Slip in the common 11% lithium and 4% tin Albany slip cone 6 glaze.

This 1 inch tall mug is glazed with Alberta Slip plus lithium, tin and some frit.

The 85% Albany, 11% lithium, 4% tin oxide brown recipe using Alberta Slip (left) and reduced lithium content (G2415E).

A variation of Albany lithium brown glaze. Alberta Slip 75, lithium carbonate 10, tin oxide 4, nepheline syenite 11, calcined alumina 5.

10% lithium and 4% tin do this to an otherwise transparent dull brown Alberta Slip.

A classic Albany glaze that often shivers

A classic Albany glaze that often shivers

These mugs have experienced very serious shivering. This is an Albany Slip glaze with 10% lithium carbonate, it is known to have a very low thermal expansion. This problem can be solved by reducing the amount of lithium or adding high-expansion sodium or potassium. However these fixes will likely affect the appearance.

Carbonate gassing can cause glaze blisters

Carbonate gassing can cause glaze blisters

An example of how a carbonate can cause blistering. Carbonates produce gases during decomposition. This glaze (G2415B) contains 10% lithium carbonate, which likely pushes the initial melting temperature down toward the most active decomposition temperatures.

Carbonate gassing can cause glaze blisters

G2415E Alberta lithium brown alternative recipe (cone 6)

Carbonate gassing can cause glaze blisters

A closeup of Alberta Slip lithium brown cone 6 recipe GA6-G on a porcelain. This has been applied very thinly, yet still covers very well and exhibits alot of variation even where thicknesses are slightly different.

Carbonate gassing can cause glaze blisters

GA6-G Alberta Slip lithium brown on the outside of a porcelain mug at cone 6. This is a thin application showing the amazing range of tones it gives.

Calcining Alberta Slip

Calcining Alberta Slip

Calcined Alberta Slip (right) and raw powder (left). These are just 5 inch cast bowls, I fire them to cone 020 and hold it for 30 minutes. Why calcine? Because for glazes having 50% or more Alberta Slip, cracking on drying can occur, especially if it is applied thick (Alberta Slip is a clay, it shrinks). I mix 50:50 raw:calcine for use in recipes. However, Alberta Slip has an LOI of 9%, so I need to use 9% less of the calcine powder (just multiply the amount by 0.91). Suppose, I needed 1000 grams: I would use 500 raw and 500*.91=455.

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By Tony Hansen

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