Liner Glazes

[Kork]

Does it make any sense to use a base glaze as a liner?

I'm using a high expansion glaze with colorants.

[bciskepottery]

One benefit would be the liner glaze would match the COE of the exterior glaze -- promoting better/consistent glaze fit. Is it necessary to use a base glaze as the liner, no, but it may mitigate potential fit problems.

[Marcia Selsor]

Base glazes are just a base  without specific colorants. Liner glazes are those used for lining inside pots and as Bciske says they are made to avoid problems with COE.

 

Marcia

[Marcia Selsor]

I have been using liner glazes since the 60s,  before digital fire or computer programs for glazes. BTW, there wasn't much talk about toxicology back then. Barium was a favorite flux for pottery in those days because of the buttery satin surface.

 

Marcia

[Marcia Selsor]

Norm,

Here is a white Liner base I started using in ^6 reduction in 1980. It came from a handout from NCECA in the 70s.

I used it with a lot of different colorants in my classroom.

It works in reduction too as white. 

White Liner ^6 Reduction

Ger. Borate   20

Neph. Syenite                 30

Kaolin                              13.3

Whiting                         9.4

Talc           17.2                    

Silica                               10

Zircopax                         10

 

ADD :Pumpkin 5% Red Iron + 3% Rutile

Gold  3% Rutile

Lt. Blue  0.5% Cobalt Carb

[Babs]

Norm,

Here is a white Liner base I started using in ^6 reduction in 1980. It came from a handout from NCECA in the 70s.

I used it with a lot of different colorants in my classroom.

It works in reduction too as white. 

White Liner ^6 Reduction

Ger. Borate   20

Neph. Syenite                 30

Kaolin                              13.3

Whiting                         9.4

Talc           17.2                    

Silica                               10

Zircopax                         10

 

ADD :Pumpkin 5% Red Iron + 3% Rutile

Gold  3% Rutile

Lt. Blue  0.5% Cobalt Carb

Marcia is this ok in oxidation, you used the word"reduction 2x did you mean oxidation on one of these occasions?

[Marcia Selsor]

sorry. Yes it works in oxidation. It is richer and warmer in reduction,

 

Marcia

[Babs]

thanks Marcia, missing my gas kiln as I type!