Tech

Clay Bodies

Porcelain (Sikora/Metz)
55.00 Grolleg Kaolin
17.00 Custer Feldspar
15.00 Silica
05.00 Pyrax Pyrophyllite
02.50 molochite (Flour, 200 mesh)
02.00 Hectabrite
=========
96.50
This is my standard porcelain body. It is a direct descendant of the Judy Cornell porcelain from the early days of the Archie Bray foundation, and can be found listed under lots of names with minor variations. My contribution is the substitution of Hectalite for VGum T. Hectalite is a brand name of the mineral hectorite, and has a much higher viscosity than VGum. It is super clean and contributes greatly to the plasticity and workability to the body. I blunge the Hectalite in 27% hot water before adding the rest of the dry ingredients. The clay is pugged in a de-airing pug mill.

Grimmer Dark Stoneware ‘D’

30.00 Foundry Hill Creme
20.00 Hawthorne Bond
30.00 OM-4
08.00 Redart Clay
12.00 Custer Feldspar
02.00 Red Iron Oxide
05.00 Fine Grog
02.00 Bentonite
00.25 Barium Carbonate
=========
109.25
This is a body of my own development. For a less porcelaneous feel, substitute Goldart for the Foundry Hill Creme. This clay body looks great under a few light glazes and opaque celadons, but can overwhelm many others. It will bloat if overfired, so hold it to about cone 9 to be safe.

Glazes

Choy Blue Celadon
50.00 G-200 Feldspar
06.00 Whiting
16.00 Barium Carbonate
04.00 Grolleg Kaolin
24.00 Flint
02.00 Red Iron Oxide
02.00 Hectalite
=========
104.00
This is a standard blue celadon, attributed to Katherine Choy, the first director of the Clay Art Center in Port Chester, NY. I suspend it with Hectalite because of the low clay quantity.

Ishii Celadon 2.0
41.53 G-200 Feldspar
19.42 Barium Carbonate
01.43 Grolleg Kaolin
34.70 Silica
00.97 Black Iron Oxide
01.94 Hectalite
=========
99.99
This is a blue celadon I developed in 1999 at Bowling Green State University from an analysis of a glaze by Mr. Ishii in Japan, listed in Ian Currie’s excellent book, Stoneware Glazes. Apparently there’s another Ishii celadon out there, but it’s not mine. This glaze likes a long, slow, firing.

Bone Ash
40.00 F-4 Feldspar
30.00 Dolomite
04.00 Talc
05.00 Bone Ash
25.00 Edgar Plastic Kaolin
=========
104.00
Gee, this is another one of those glazes from the 60’s. There’s another version out there without the talc. Responds well to iron in clay bodies and slips, and even looks nice as a white glaze on porcelain if not too thick.

AA no Corn
26.75 Custer Fledspar
33.97 Whiting
26.96 Edgar Plastic Kaolin
12.32 Silica
=====
100
+ 4% Copper: Blue-Green, turquoise, black crystals.
+ 6% Titanium, 4% Red Iron Oxide: Taffy
+ 4% Titanium, 6% Red Iron Red/Orange Crystal
This is a re-calculation of the well-known Val Cushing AA base glaze (46 Cornwall, 34 Whiting, 20 EPK; also known as Diane’s Blue Black, Mike’s Green, Val’s Taffy, etc.) that I did one time when I got sick of breaking up Cornwall Stone rocks. It’s pretty much the same glaze. Probably not entirely food safe, so best to use it on the outsides of functional pots. Responds well to most colorants and looks great in atmospheric firings, though it can get runny when excited by too many vapors. As can we all.

Runny Money
23.29 Custer Feldspar
29.12 Whiting
09.71 Strontium Carbonate
03.88 Dolomite
15.53 EPK Kaolin
17.47 Silica
01.00 Cobalt carbonate
=========
100.00
A fake ash glaze of my own design that I came up with while fiddling around with the Insight glaze calc program. I started with a Redart-based fake ash and recalculated it using iron-free materials while maintaining the flux balance of iron in reduction. It does what you’d expect a fake ash glaze called Runny to do. It’s surname is Money because it’s blue and everyone loves blue, right?

Slips

So-So Blue
50.00 Nepheline Syenite
50.00 EPK Kaolin
00.25 cobalt carbonate
=========
100.25
Mix this up to the consistency of milk, and apply to greenware if you don’t want cracking. Apply to bisque if you think cracking is OK. It looks much bluer in the bisque state than when mature, so don’t be alarmed. This slip does neat things in atmospheric kilns, and under celadons. For a little more action, add 1% soda ash.

Orange Flashing Slip
40.00 Edgar Plastic Kaolin
31.00 Helmer Kaolin
02.50 Redart
10.00 Nepheline Syenite
11.00 Custer Feldspar
08.50 Silica
=======
102.50
A combination of a couple of slips I had left over in buckets that I poured all together one day. It works well, and so I incorporated the recipes and use it like that. Mix to the consistency of milk and apply to greenware, or to bisque if you like crackling where it’s thick.

Leave a Reply

Your email address will not be published. Required fields are marked *