CASTING AND MODELLING.
One of the leading authorities in this country has aptly said, "The
ideal taxidermist must be a combination of modeller and anatomist,
naturalist, carpenter, blacksmith and painter. He must have the eye of
an artist and the back of a hod carrier." This should not dismay the
beginner for such casting and modelling as will be indispensable are
comparatively simple.
In order to cast we must have molds and in our work these are chiefly of
plaster. They are divided into two classes known as piece and waste
molds. As the names indicate the latter is wasted or destroyed after
making one copy while the piece variety can be used for a number of
reproductions. The piece mold is divided into sections in such a way as
will allow its removal without injury to either mold or cast. The waste
mold is made from soft or fleshy objects which can be drawn from it in
spite of projections known as undercuts.
As an illustration let us procure a cast of a deer's nose for reference
in mounting the head later. For our purpose we wish a cast of the nose
and lips, so with the head in the flesh at hand, the hair as far back as
the corner of the mouth is coated with clay water to prevent the liquid
plaster from penetrating and adhering. This done the head is propped up
on the table and a rough box arranged around it, which will reach nearly
to the mouth as the head is placed with nose uppermost. Pour sand in
this box until only as much of the nose projects as is desired to cast.
Now mix in a bowl or basin a sufficient amount of water and plaster of
paris to cover the surface of the deer's nose about 1/4 inch thick. This
should be of the consistency of cream and enough bluing or lampblack
should be added to give it a decided tint.
If the skin of the lips and nose is disposed naturally the plaster may
be ladled on with the spoon, endeavoring to get about an even coating.
Wash any remaining bits from the dish and mix say twice the amount of
plaster without coloring. Distribute this over the other and allow to
harden, which they will do in about 20 minutes. A little careful work
will withdraw this mold from the nose and it may either be laid aside or
used at once in making the cast.
To do this brush the inside with clay water and pour it full of plaster.
Shake well to prevent bubbles and when hardened chisel away the mold. In
doing this lay it on the lap or a cushion and chip off the mold. When
the first layer (the colored one) appears work with caution to avoid
marring the cast.
If a wire loop was inserted before the plaster hardened the cast may be
hung on the wall for future reference.
[Illustration: THREE PIECE MOULD OF HEAD.]
The preparation of a piece mold is somewhat different. A mold can be
made in two pieces of a round object like a ball and if each piece is
exactly one-half, it will draw, because there is no point under which
the plaster will hold. Any hollows or projections will form "under cuts"
necessitating making the mold in a number of pieces that it may relieve
or be lifted off the cast. Molds of heads from which to cast paper forms
are often wanted and are easily made. With the skinned head of a fox,
let us say, on the table, the lower part is embedded in fine sand or
clay about on a line with the mouth. Cover half of the exposed upper
part of the head also with clay. Pour to the depth of at least 1/2 inch
on the remainder.
Remove the clay from the other half of the face, and after
countersinking two or three shallow holes in the edge of that part of
mold already made and coating that edge with clay water, pour plaster
for the second piece of mold. When this hardens pick up head from its
bedding of sand or clay and turn over so the final piece of model can be
made.
Always coat the edges with shellac or clay water to prevent adhesion and
countersink a few holes for dowels to aid in holding the pieces in
place. Dry out thoroughly and shellac the whole interior and joining
edges. If it is slightly oiled before using a great number of casts may
be made from it. This will give us a complete cast of a fox head with
closed mouth.
A shorter method to obtain molds of the upper part of the head and face
for making paper half-head forms, is to imbed in sand or clay as
directed and stick a piece of stout thread or cord along the central
lines of the head and face. A little clay will hold this in place and
there should be a few inches surplus at each end. Mix the plaster and
cover the entire top and sides of the head with it. Just as the plaster
begins to harden draw the thread upward through the stiffening plaster
cutting it in two parts which are easily removed when hard. When dry
coat with shellac, tie together and they are ready for use.
[Illustration: MAKING MOULD FOR HALF HEAD.]
To cast half head forms soak some paper and after coating one side with
paste, press into the mold with the fingers. The first layer should be
quite soft so as to crowd into all depressions. About six layers of
building paper is thick enough for a fox head size. When dry cut the
cords and detach the mold.
Molds for deer head forms are made in two pieces, one for each side of
the head, and are necessarily not carried completely around the antlers.
This gap is just filled in the head form by the plate of bone bearing
the antlers, which is sawed from the skull.
The entire neck may be molded in connection with the head if desired.
Gelatine and compositions of glue and wax are used for molds where fine
definition is desirable, and wax as well as plaster and paper for making
casts. The ground up paper pulp is used for many casts, pressing it into
mold with fingers and spatulas.
Clay is the stand-by of the taxidermist modeller. That furnished by art
dealers is best, but for common use potter's clay is all that is
necessary. A little glue mixed in plaster delays its setting and makes
it harder when dry. Good papier mache is one of the best materials for
much modelling and wax for very fine work. Tools for this work may be
purchased or home made of wood, bone or metal.
Many forms of fishes and reptiles are difficult or impossible to mount
by ordinary methods. On these the caster and modeller may work his will,
and if he also possesses a good eye for color the results may be of the
best. As an indisputable record of anatomy even a poor cast is valuable.