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M332

Description

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. M332 has exceptionally high dry strength.

Process Properties

M332 has a highly plastic base with a sand complement to add texture. While it throws very well and generates sufficient slip, it can be 'grabby' during throwing with care to make sure pressure surfaces are not well lubricated. Once you learn how to throw it you will be amazed at what it can do.

Cautions: Because of the sand content it can develop splits during construction or throwing if water is allowed to sit on the surface at stress points (i.e. the outer belly of a thrown vase). In addition, when pulling handles, you must develop techniques to minimize splitting. It is best to keep sponging of leather hard or dry ware to a minimum as this tends to remove fine particles at the surface and expose the coarser ones (a problem on the lips of functional ware. M332 needs to be dried with care to avoid cracking. Turn open shapes over as soon as they will support themselves and cover ware with cloth and plastic (not just plastic) to even out any gradients in water content.

Firing

M332 fired bars from cone 4 to 8 oxidation (bottom to top).

M332 burns to a warm brick-red at cone 3-5, shifting to a medium variegated red brown at cone 6, and finally to a grey 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 6 and 7. Fire carefully to avoid overshooting the target temperature and losing the red. The redish color depends on the body firing to 4-5% porosity.

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 using a drop-and-soak firing schedule. In other cases it may be necessary to fire the bisque a little higher to expel more gases of decomposition.

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 dark brown brown. 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 colors.

Glaze Recipes

You can develop a compatible glossy or matte base for this body from our suggested starting point base clear recipes . Add colorants, opacifiers and specking agents to get endless visual effects. For slip decoration, be careful to match drying and fired shrinkage of the slip with the body. Our standard middle fire L3954B engobe will work.

Thermal Expansion

We do not supply a thermal expansion value. The reason is that such numbers often mislead users. First, a body has different thermal expansion characteristics when fired at different temperatures, schedules and atmospheres. Dilatometers are only useful when manufacturers can measure bodies and glazes over time and in the same firing conditions. If a chart is supplied here, please view only as a way to compare one body with another.

Another significant issue is that many customers compare measured thermal expansion numbers with calculated values of glazes in efforts to fits those glazes to a body. This does not work. Calculated values are relative only and have limitations that must be understood. The best way to fit glazes to your clay bodies is by testing, evaluation, adjustment and retesting. For example, if a glaze crazes, adjust its recipe to bring the expansion down (using your account at insight-live), fire a glazed piece and thermal stress it (300F into ice-water). If it still crazes, repeat the process.

If we recommend a base clear or glossy glaze, try calculating the expansion of that as a rough guide to know whether your glazes will fit.

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

Gallery

M332 bowl by Louise Bouchard.

Safety Data Sheet

Click here for web view.

Logo Plainsman Clays Ltd.
702 Wood Street, Medicine Hat, Alberta T1A 1E9
Phone: 403-527-8535 FAX:403-527-7508
Email: plainsman@telus.net