M332

Mid-temperature, sandy, plastic, semi-vitreous, warm medium brown, native throwing body.

M332 is made from seven different native clay materials and it is generally used for two reasons: its appealing warm red fired color at cone 5-6 and its combination of a sandy texture and high plasticity. M332 is attractive when used with glazes that absorb and highlight body iron and with ware that leaves some bare patches of clay showing. Many people find the texture and feel of M332 matches their way of throwing and they find they can make thinner and larger pieces.

Process Properties

M332 has a highly plastic base with a sand complement to add texture. It throws and generates slip well. However M332 requires that you exercise caution in some areas. It can be 'grabby' during throwing if inadequate water or slip are used. Because of the sand content it will develop splits during construction or throwing if water is allowed to sit on the surface at stress points (i.e. the belly of a thrown vase). Also, you will find that techniques will have to be developed to minimize splitting during the pulling of handles. It is best to keep sponging of leather hard or dry ware to a minimum also as this tends to remove fine particles at the surface and expose the coarser ones. This can be a problem on the lips of functional ware where some glazes tend to thin during firing and expose sharp particles of sand making the rim rough.

M332 needs to be dried with care to avoid cracking. We recommend the use of a grogged slip with minimal water content to assure even shrinkage on joins. Turn open shapes over as soon as they will support themselves and cover ware with cloth and plastic (not just plastic).

Firing

M332 burns to a warm brick-red at cone 3-5, shifting to a medium variegated brown at cone 6, and finally to a greenish brown by cone 8. If you want the attractive red color remember that M332 undergoes a sudden color shift from red to brown between cone 5 and 6. You should fire carefully to avoid overshooting the target temperature and losing the red. If you fire to cone 6, the body will remain a similar color through cone 7 and will be more vitrified.

Glazing

Since we add materials with coarser particles and impurities to give the surface a more earthy appearance you can expect that the body will not provide perfectly clean glazed surfaces for functional ware. Glaze disruptions such as small pinholes and specks will be common. You can often solve this by soaking the firing at top temperature, firing a little higher, or using a more fluid glaze. In other cases it may be necessary to fire the bisque a little higher to expel more gases of decomposition. It extreme situations you may have to apply a slip between glaze and clay. On the other hand you may find that the gas expulsion 'activity' at the surface coupled with the body's coarser speck producing particles can 'liven up' a glaze and give it much more interesting effects.

Although M332 burns a warm red color at cone 5, if you apply a transparent glaze it will flux the surface and the color will likely darken and turn a brown shade characteristic of a cone or two higher. Thus, if you need to achieve red glazed colors it may be necessary to fire at cone 3-4. Also, because this is an iron-brown burning body it will impose some of its color on all glazes, darkening them and muddying most colors.

Glaze Recipes

You can develop a compatible glossy or matte base for this body from our suggested starting point base recipes available on our Internet web site at http://digitalfire.com/education/glaze/cone6.htm. Information is given on how to fit the glaze to your body and how to customize it it for colors, opacity, speck, variegation, etc. For slip decoration, be careful to match drying and fired shrinkage of the slip with the body since low temperatures generate little glass to adhere the slip.

Physical Properties

 Drying Shrinkage: 6.0-7.0%
 Dry Strength: n/a
 Water Content: 19.5-20.5%
 Drying Factor: c332
 Dry Density: n/a

Sieve Analysis (Tyler mesh):

     +48: 0.1-0.5%
   48-65: 2.0-4.0
  65-100: 6.5-9.5
 100-150: 6.0-8.0
 150-200: 8.0-11.0
 200-325: 8.0-12.0

Fired Shrinkage:

 Cone 4: 3.0-4.0%
 Cone 5: 3.5-4.5
 Cone 6: 4.0-5.0
 Cone 7: 4.5-5.5
 Cone 8: 5.0-6.0

Fired Absorption:

 Cone 4: 5.5-7.5%
 Cone 5: 4.5-6.0
 Cone 6: 3.5-4.5
 Cone 7: 2.5-3.5
 Cone 8: 1.5-2.5

Chemical Analysis

 BaO       0.4
 CaO       0.5
 K2O       2.4
 MgO       0.8
 Na2O      0.4
 TiO2      0.6
 Al2O3    16.0
 P2O5      0.1
 SiO2     69.2
 Fe2O3     2.7
 MnO       0.0
 LOI       6.9%

Plainsman Clays Ltd.
Box 1266, 702 Wood Street, Medicine Hat, Alberta T1A 7M9
Phone: 403-527-8535 FAX: 403-527-7508

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