NEUMAN RED CLAY
by David G. Wright
Neuman Clay
I began using red burning clays after my experience in graduate school at the University of Colorado in Boulder. In fact, the word "Colorado" is Spanish for "red or reddish". The landscape of the desert Southwest has always held a tremendous fascination for me since I was very young! I knew it would affect my artwork, but I was unsure of how or when.
Several years later, I found myself living in New Jersey to be close to my family, but longing to be near the desert southwest. My desire to be in the Southwest manifested itself by developing clay bodies that provided me the color, texture, and feeling of that region. I began my search for a deep reddish color, cone six, oxidation fired, throwing body with good working qualities.
To get a red clay at high temperature though, I needed a primary clay that was reddish, so I tried Redart, but quickly learned that it only gave me browns. I then remembered as a student, using a red clay called PBX Valentine fireclay. Unfortunately, PBX was no longer available, so I needed an alternative.
I found a clay called Neuman Red, mined in Sacramento, by H. C. Muddox. *Neuman has a bright orange color and is very refractory, having a PCE (Pyrometric Cone Equivalent) of 19-20. Although, the company considers it a ball clay, as 41.7% of its particle size is -200 mesh, the dry clay feels toothy like a fireclay.
Using a combination of Neuman Red clay with Redart clay I quickly achieved the results I wanted. Neuman provided the color while the Redart made the clay vitrified. The Redart, which would normally go brown, was now able to stay a terra cotta color at higher temperatures.
At the same time, my friend and teacher Bill Daley, was also in search of a red clay. Bill had already developed a red vitrified stoneware using PBX in 1973, as a result of a commission he had received from the Ritz Theater in Philadelphia. He was interested in matching the red brick structure, so he had to develop a red clay body that could withstand the elements, since it would be outdoors. Up to that point, Bill had been using a brown colored clay body that was fired in a reduction atmosphere. He found himself enjoying the new red clay color and also liked the consistency of oxidation firing. At the time, no one else was using a high temperature red stoneware, and it made Bill's pots even more distinctive and original.
Unfortunately, as I mentioned before PBX had stopped being mined, so Bill along with many others, had to change his clay formula to something else. I began using the Neuman clay in 1993 and introduced Bill to it soon after. We did a lot of tests and shared our information, developing the D/W body listed below. Bill ultimately refined his own clay body using more Redart clay for greater vitrification and a darker color.
Other Claybodies
I tested many clay bodies afterward for cone's one through six, as I liked to work at a variety of temperatures. As I tested, I became more and more interested in the many types of clays I discovered. I was fascinated by the variety of color and texture of the clays available. Like the desert Southwest landscape, I wanted clays that were rich and warm, but that could be produced consistently in an oxidation atmosphere.
In the end, I developed a variety of different reddish clay bodies using this combination. Along the way, I discovered clay bodies that were not only red, but also orange, tan, brown, chocolate, white and maroon. I have shared these clay bodies with countless students, who along with myself have had great success using them. I would like to share these recipes with Ceramics Monthly readers.
* A chemical analysis of Neuman Red along with other information can be found in Bulletin #99, by Waldimer Dietrick, at the Bureau of Clay Resources and Ceramics Industry of California.
Neuman/Redart Claybodies
D/W RED BODY
Neuman Fireclay 40A red burning stoneware that is better for hand
RedArt30building than for use on the wheel.
Fireclay20
Ball 10
Total 100%
Bentonite 2%
Fine Grog 5%
Barium Carb. 1%
WRIGHT "RED" STONE
Neuman35This is my current body. It has a nice color and is
RedArt30very forgiving!
Fireclay25
Ball clay10
Total 100%
Bentonite 2%
Barium Carb. 1%
DALEY'S BODY C6
REDART 120This is Bill Daley"s current body based on our
Neuman 80original D/W body, it is less red, but as tight as a
Fireclay 60drum at cone six oxidation.
Ball 40
Total 300%
Grog 10%
Bar. Carb. 1%
BACH'S RED FOR C6-8
Neuman 40Beautiful Orange-Red, but not as tight as the
RedArt 25others. Perhaps 3-4% absorption at cone six.
Fireclay 25
Ball 10
Total 100%
2% Bentonite
5% -120 Molochite
1% Barium Carbonate
MAROON RED C/6 ox.
Redart40Deep rich Maroon Red. Very tight at cone six.
Neuman40It is extremely short, but good for sculpture.
Ball 10
Flint 10
Total 100%
Add: Bar. Carb. 1%
DAVID'S BRICK RED C/6 ox.
Neuman5013% Shrinkage and 3% Absorption at cone six.
Redart20A little more red than Wright "RED" Stone, but not
Ball10as plastic either.
Neph. Syn.10
Flint10
Total 100%
Add:Fine Grog 5%
Bentonite 3%
Barium Carb. 1%
TIGHT RED
Neuman1/3 by weightMy best throwing body.
Redart1/3Deep reddish color and very tight!
Ball clay1/3
1% Barium Carbonate
Grog optional
DAVID G. WRIGHT'S CONE ONE - FOUR CLAYBODIES
Chocolate Body C/1-4
RedArt Clay 50 lbs.A fairly good throwing body with
Ball Clay 20 lbs.moderate dry strength. Fires to a sweet
Barnard Clay 20 lbs.milk chocolate color with about 2%
Fireclay 10 lbs.absorbtion at cone one oxidation.
Total 100 lbs.
Bentonite 2%
Bar. Carb. 1%
RED Throwing Body C/1-4
RedArt Clay 70 lbs.A fairly plastic body for throwing or
Ball Clay 20 lbs.handbuilding. A good, tight body, with 2%
Fireclay 10 lbs.absorption at cone one. A Red-Brown color in
Total 100 lbs. oxidation. An addition of 10% Neph. Syn.
will increase vitrification, but darkens
Bentonite 2% the color considerably.
Bar. Carb. 1%
#18 RED C/1-4
RedArt Clay 80 lbs.A smooth, short body for throwing.
Ball Clay 10 lbs.A deep Red that gets darker when heat
Flint 10 lbs. increases. Beautiful deep red at C/4.
Total 100 lbs
Bentonite 2%
Bar. Carb. 1%
David's Toast Body C1-4
RedArt Clay 100 lbs. A high iron, very workable clay for
Ball Clay 100 lbs. throwing and handbuilding. A Toasty
Fireclay 50 lbs. brown color in oxidation.
Barnard Clay 50 lbs.
Total 300 lbs
Bentonite 2%
Bar. Carb. 1%
Grey Stone C/1-4
Six Tile Kaolin30 lbs.I use this clay on occasion. It works well
Fireclay30 lbs.and has a lovely grey color.
Ball Clay20 lbs.
Neph. Syenite10 lbs.* Iron Chromate is not very healthy to breathe!
Flint 5 lbs.* Try to work wet and keep down the dust!
Fritt 3124 5 lbs.
Total 100 lbs.
Add: 2% Bentonite
Add: 10% Iron Chromate*
Add: 5% Alberta Slip
Other Claybodies for Cones 5-6
TAN THROWING BODY
Ball Clay 125 lbs.A nice all purpose clay!
Fireclay100 lbs.
Redart 75 lbs.
Total 300lbs.
Plus: 5% Fine Grog
DAVID'S PORCELAIN C/6
Six Tile Kaolin 125This sweet white porcelain is my favorite!
Kaopaque 20 25
Ball Clay 20
Neph. Syn. 65
Flint 200m 65
Total 300
Plus:Talc 5%
Veegum-T 1.5%
"SANDY" PORCELAIN
Six Tile Kaolin 100This porcelain is short but fun to work with, as it is
Silica Sand 100extremelyrough and toothy and has a nice textured
Nepheline Syenite 50 surface.
Flint 50
Total 300
Plus: Talc 5%
Bentonite 3%
TOASTY STONEWAREA nice all purpose toasty warm stoneware for
RedArt1/3 by weightelectric firing.
Ball clay1/3
Fireclay1/3
Grog optional