146 
RERAMIC STUDIO 
GRAND FEU CERAMICS 
VI.— Casting 
Taxile Boat 
N presence of the many difficulties 
of the various processes for handling 
paste which I have described, which 
difficulties are overcome only by 
special training and long practice, 
I decided early to adopt the mode of 
fabrication called casting, so as to 
obtain results more easily and 
surely. This process is very attrac- 
tive. It is best suited to the work 
of isolated artists, because it does not necessitate an expensive 
outlay and presents no serious difficulties. It requires only 
attention and care. It is exclusive to porcelain, as it is not 
suitable to gres. In this way can be obtained at will, in various 
shapes, the smallest as well as the largest pieces, vases two 
inches or nine feet high, with fancy shapes like the 
Rosenburg or the Dresden wares, the thickest ceramics of 
Chaplet and of Bing & Grondhal as well as the thimiest egg 
shells of the clever Japanese. It is simply a question of 
moulds, which are costly and cumbersome onl3^ for large pieces. 
On account of my modest resources and of the little leisure 
which my work for the State factory leaves me, I have confined 
myself to works of small and medium size. The most important 
of my cast pieces is the triumphal vase reprodticed in the learned 
Encyclopedia of Ceramics of W. P. Jervis. It is 16 inches high. 
First, the slip, whichhas been passed through a screen No. 1 20, 
is prepared in a cylindrical pitcher with spout, having a large 
opening, so as to make_cleaning easy (fig. 8), and containing at 
least double the capacity of the mould, or in a common coffee 
pot (fig. 9) . The sHp is gently stirred with a wooden spatula, 
in order, a very essential point, to expel all the air bubbles, to 
dissolve all the clods and make the paste quite Uquid without 
excess of water. It is called well prepared for casting, when it is 
serai-pasty, that is, when it contains just enough water to make 
it fluid. If it has too much water, the slow time it would take 
for the water to be absorbed would be injurious. There is a 
happy medium which is left to the judgment of the operator. 
1 
1 
i 
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7 
With this process there is no neecl_^of learning to throw, 
beat, turn and finish the paste. The thickness is acquired 
mechanically with a perfect regularit}^. It is the triumph of 
the easy and the joy of the beginners. 
This mode of fabrication is based on the property which 
moulds in dry plaster possess of absorbing water. If in one of 
these moulds, the liquid paste called slip is introduced, the water 
will be rapidly absorbed, the paste will become firmer and will be 
spread uniformly over the walls of the mould, following all 
curves. When a sufficient quantity has thus been fixed on the 
walls, if the excess of sliiD is poured out, there will remain a coat 
of coagulated paste reproducing exactly the outside outlines of 
the piece and the inside of the mould. 
For simple moulds, the pouring out is made through the 
top, by turning them upside down. For those of medium and 
large size, which are complex and heavy to move, the pouring 
is done through the bottom. 
By following exactly the following explanations, any- 
body wishing to attempt grand feu ceramics, will become in a 
weels: familiar with the operation of casting. 
Let us take as an example of a small piece, the casting of 
the two shapes, (fig. 6 and ll). The mould will be simple, 
as no projecting part in the shape will prevent the piece from 
coming out of the mould easily (fig. 7 and lo) . 
The slip is poured into the mould which is filled to the top. 
The absorption of water begins at once, and the slip which goes 
down gradually is constantly replaced so as to keep the liquid 
at a constant height in the mould. All the phases of the 
firming up of the paste can be watched easilj^, and when the 
thickness is judged to be sufficient, the mould- is turned upside 
down, and the excess of useless slip poured out. One must 
carefully avoid jerks in this operation. During this pouring 
out, some slip is left on the edges of the mould. As soon as it is 
coagulated, it is taken out with a wooden knife or with the 
fingers. 
Gradually the water is completely absorbed and the shape 
begimiing to shrink, parts from the mould. The vase is made 
(fig. 11) . The next day it is firm enough to be delicately taken 
out of the mould and put away to dry. 
After using either the sun rays, or the action of a fire or of 
the wind, to dry the mould, the operation can be renewed. 
And the vases comes out like cakes. 
The disadvantage of the simple moulds which are emptied 
from the top, is that the least jerk will bring a deformation of 
the paste which is only firm, but not yet solidified. 
If the shape to be made has one or rnaity projecting parts 
which do not allow a simple mould, one out of which the cast 
piece can come by itself, one inust use moulds in many 
pieces, which are emptied through the bottom (figs. 13, 15 and 
20). This mode of operation is based on the plwsical law dis- 
covered by Galileo, that liquids tend to seek the same level in 
commrmicating vases. 
In this case it is necessary' to construct an apparatus. 
