-
How is CLAY
worked?:
There are different ways of working clay. All through the history of
DERUTA, there have been three basic ways in which the process has
been, and still is, carried out. Throwing
of clay on the WHEEL is obviously the best-known and most
fascinating method, with which the majority of objects produced in
DERUTA were and still are created. Throwing on the wheel is the
oldest technique known, and is to be found illustrated on Greek
vases.
The potter’s
wheel is essentially made up of a vertical shaft with a disk on top
where the manipulations needed for moulding take place. At the
bottom of the shaft is a flywheel, originally driven by the
potter’s feet; nowadays the wheel is electrically powered, so the
potter expends considerably less physical energy. Only objects with
a circular section, except for later additions, can be produced on
the wheel.
When objects
do not have a circular form, shaping has to be done using Moulding. The moulds are made of plaster, which is the only material
that, being porous, does not allow the clay to stick to it. A model
is therefore constructed on which a casting of plaster is made; an
external mould is thus obtained which can be used to produce the desired objects. The oldest method used for moulding in
Deruta is pressing. The
clay is pressed into the mould by hand, after which there is a delay
while it dries out to the point that it can be detached from the
plaster. Today, this method has almost totally been superseded by
hydraulic presses, which greatly facilitate the craftsman’s
work.
The third method of working clay used in Deruta is Slip-casting.
In this technique plaster moulds are again produced, between
which is poured a casting of liquefied clay. After a certain period
of time the moulds are emptied, ensuring that the desired thickness
of clay remains attached to the plaster. After allowing the clay to
dry, the moulds are opened and the object is finished off. In all
shaping methods the object has to be finished off: this involves
cleaning away the excess clay and then carrying out all the
additional applications needed to finalise the object. This phase of
production must take place before the object is completely dry,
while the clay can still be modelled.
The final but
equally important phase is drying. The objects must be completely
devoid of moisture before the first firing in the kilns, otherwise
they are sure to break.
There are of
course many other ways of shaping an object, but I have limited
myself to describing these three because in my opinion they are the
ones that have been used most in DERUTA throughout its history.
|
Whell
NEXT
- The
First (biscuit) Firing
>>
.
|
