Friday, December 16, 2011

#1 Cone 6 Porcelain
15   6 Tile Kaolin
15   C&C ball clay
20  Grolleg Kaolin
20  Silica 325 mesh
15   G-200 feldspar
5    Talc
5    Frit 3195
5    Wollastonite
2    Bentonite (added)

Adsorption:  0%
Shrinkage:  12.5%
Slumping:  moderate
Translucency:  medium


#2 Cone 6 Porcelain
50   Grolleg Kaolin
20   Silica 325 mesh
17    G-200 feldspar
3     Talc
3     Frit 3195
5     Wollastonite
2     Veegum T

Adsorption:  0%
Shrinkage:  12.5%
Slumping:  moderate
Translucency:  High


The first clay body was developed to be as plastic and affordable as possible, while maintaining a decent degree of translucency.

The second is the most translucent, but has a higher cost. If you want an even greater degree of whiteness and translucency, New Zealand Halloysite (aka kaolin) can be substituted for some or all of the Grolleg.

I definitely recommend doing small test batches to see if these recipes will work for you, they may need to be adjusted.


Notes on materials:

G-200 feldspar: I developed this recipe over a decade ago, so it is the old G-200. If using G-200HP or other feldspar, modifications will be necessary.

Bentonite:  Western 325 mesh

Wollastonite:  Needs to be sieved, or you will have lumps in your clay, I use 60 mesh.

Veegum T or macaloid:  Always add it to the water first, I find it necessary to slowly sift it into the water.


Mixing:

I mix these clays into a slip to get everything evenly distributed, and soaked well.
I add all of the fluxes to the water first (unless using veegum), mixing well to disperse them, a small amount of clay from the recipe can be used to help prevent settling if necessary. Then add clays, the bentonite is dry mixed with another clay before adding.



I hope this helps those interested in cone six porcelains, and those who enjoy experimenting.