St Amend Cordierite Almond Stoneware Clay 10 kg (R21914)

Single and Double Cooking
Biscuit baking temperature: 980°C
Glazed baking temperature: 1250°C - 1280°C
Packaging: 10 kg (22,05 lb)

Technicial Specifications :
Drying shrinkage: 5.5%
Shrinkage at 1280°C: 6.2%
Porosity 1300°C: 1%
Expansion coefficient: 41 x 10-7
Saint Amand sandstone, geologically termed "Myennes clay", in the Middle Albian (-113 to -100 Ma)
It is a natural clay that comes from layers formed at the very beginning of the secondary age.
The sprawl sinks below the Loire from Saint Amand en Puisaye and heads to Cosne sur Loire to reappear in Borne's cradle.
The formation of the GSA is due to the alteration of kaolin and feldspars in the volcanic basement of the Morvan mountains (Château Chinon massif).
The lacustrine deposits of the fragments have interlayers of kaolinite and feldspar particles, mostly potassium, followed by mica and quartz.
The black aspect of the soil is linked to the vegetative part, dissolved and then structured in humus.
In summary, the sandstone of Saint Amand consists of:
40% quartz
57% kaolinite
3% micaceous minerals (feldspathic sources)
0.8% organic parts

Techniques Features:
This Mud is naturally balanced between plasticity (fineness of particles) and elasticity (organic phase), allowing shaping of all ceramic applications.
The production of the paste, in humidity, is adapted to the production methods and gives the following hardness classification:
5/6 standard turning.
4/5 Flexible turning and calibration of plaster molds.
6/7 Hard Turning and Ram Process Pressing.
7/8 Metal mold pressing.

Tips:
If it is important to choose the right hardness index, note that the moister the mud, the greater will be in elasticity (tensile capacity), detrimental to plasticity.
If there is a habit of working with a lot of water during shooting, compensate with an index of 6/7.
This preserves the harmony of St Amand.
Provide slow cooking following a GSA curve for food containers, 11-12 hours and a maximum of 1280°C.
Rapid temperature rise will damage the sludge.
With the quartz ratio, the transition between 450° and 600° is made at a rate of 50°/hour.
At the end of cooking, wait half an hour for glaze and 15 minutes for biscuits.