cottle

Place a piece of wood inside the cottle and pour onto that.

6. Mouldmaking and Plaster of Paris 1991

Special clamps can be made to hold the cottle in position and are very convenient if many moulds are to be made, but this is rarefy done.

6. Mouldmaking and Plaster of Paris 1991

For most purposes, a “universal cottle” is used, which can be adjusted to any shape.

6. Mouldmaking and Plaster of Paris 1991

This is filled with plaster of paris, and as soon as it has set enough to hold its shape, the cottle is removed and rough shaping is done immediately while the plaster is still wet and soft.

6. Mouldmaking and Plaster of Paris 1991

Hold it together with rubber bands, turn it upside down’ cut notches and place a cottle around it.

6. Mouldmaking and Plaster of Paris 1991

In practice, bricks, clay, etc., are generally used to hold the cottle.

6. Mouldmaking and Plaster of Paris 1991

Allow about 4 cm between cottle and largest diameter of the vase.

6. Mouldmaking and Plaster of Paris 1991

Take care with this step, as the pressure of liquid plaster is sometimes surprising, and a lot of work can be lost if all the plaster runs out of the cottle.

6. Mouldmaking and Plaster of Paris 1991

FIGURE 6. 5.2-A Universal cottle with clamps made from iron bars.

6. Mouldmaking and Plaster of Paris 1991

A multiple-piece mould can also be made without using a cottle.

6. Mouldmaking and Plaster of Paris 1991