The glaze that drove me mad!

I spent a very long time experimenting with this white-ish stoneware glaze, cone 8. Trying to get it just right.

The whole point of this glaze was to replicate a reduction fired look in an electric kiln. It’s pretty much an opaque glaze but I played with the recipe to get just a little of the clay body to show through, for a bit of warmth. I developed a matt and gloss version of the glaze. On the clay body I made up here there’s no crazing or any other bad glaze faults or defects. I also tried to achieve the slightly reddish burnt look on the body where the glaze stops.

Simple White Stoneware Gloss 3h, cone 8, oxidisation

Petalite – 20
Potash feldspar – 20
Serina kaolin – 18
Wollastonite – 15.5
Silica – 15.5
Zicropax – 4
Magnesite – 5
Lithium carbonate – 2

Simple White Stoneware Matt 3i, cone 8, oxidisation

Petalite – 32
Potash feldspar – 11
Serina kaolin – 18
Wollastonite – 13
Silica – 13
Zicropax – 4
Magnesite – 7
Lithium carbonate – 2

Cobalt oxide and a few other ingredients, brushed on

Cobalt oxide and a few other ingredients, brushed on

The variegated look of the oxide brushwork is also a mock reduction effect. It’s a mixture of cobalt oxide, iron oxide, water and a bit of whatever clay body you’re using. Sounds weird, but it works. You can vary the colour from a hard blue through to a bluey-grey. This recipe I adapted from one I was given by Suzanne Passmore when she retired.

Blue oxide decoration
Clay – 3
Red Iron oxide – 1
Cobalt oxide – 1

Brown oxide decoration
Clay – 2
Rutile flour – 1
Manganese dioxide – 1