Flexible Molding Compound
Formula: Remelts. Use it over and over again
This is new mold material is much superior
to ordinary gelatin
(mold glue) and is very easily made. It does not shrink or dry
out like ordinary casting gelatins. If made according to
directions it will retain all its original qualities
indefinitely, and can be remelted when necessary.
FORMULA:
Flake Gelatin . . . . . . . 4 1/2 pounds
Water . . . . . . . . . . . 4 1/2 pints
Glycerin . . . . . .. . . . 9 pounds
Glucose . . . . . . . . . . 1 pound
Denatured Alcohol . . . . . 1 ounce
PROCESS: Place the gelatin in a large container and pour the
water over same; then cover container with damp cloth to
prevent evaporation. Mix up thoroughly with the hands every ten
minutes to keep water evenly distributed, otherwise the bottom
will absorb too much water and the top portion will dry out and
harden. Replace cloth after each mixing. After gelatin is
thoroughly softened, squeeze out all surplus water (if any), and
place in double boiler and melt. A few minutes after it begins
to melt start stirring and keep stirring until the gelatin is
all melted and free from lumps. Then add the glycerin (which
should have previously been heated) and stir until blended.
Continue to stir until all ingredients are thoroughly
incorporated and remove from fire. Now add the alcohol and stir
until thoroughly blended with the rest of the mixture. The
compound is now ready for use. Do not add water when remelting.
A double boiler can easily be made by using
two metal buckets or
pans, one larger than the other. Put a few stones in the bottom
of the larger container and partly fill with water. Then put
mold compound into smaller container and place it in large
container. There should be enough water in large container to
come up at least half way on outside of small container. The
stones are to prevent the small container from touching the
bottom and thereby burning the mixture. Leave unused material
in container in which it was melted.
HOW TO GET THE ABOVE COMPOUND TO MAKE MOLDS: First select the
article you desire to duplicate. Almost all articles can be
duplicated, such as celluloid novelties, metal toys, dolls, etc.
Articles cast in compositions, book-ends, emblems, etc.
If the article to be cast is very simple,
with one entire side
flat like a book-end, emblem, or plaque, it is only necessary to
lay it on some flat, smooth surface, like glass or marble, face
up. Place a frame of wood or metal bars around it, having oiled
the object and other parts well; then pour the pliable mold
composition over it. However, for more complicated things such
as door stops and novelties in forms of dogs, cats, dolls, etc.,
you will have to make a mold in two pieces.
To make two piece molds, plaster should
be used to reinforce the
mold. To make good molds you must bear in mind that both this
compound and rubber gives under the weight of the casting
material. Therefore, some means must be used to hold molds made
from these materials in shape. It must be made so that the mold
can easily be removed from the reinforcing shell so that the
mold may then be removed from the casting without damaging it.
After you have applied the molding composition
or last coat of
rubber and compound starts to set - spread about 1/2 inch
thickness of plaster mortar over it with a trowel, let set and
then remove it. For full body molds in two parts - make one
half, let it stand until set, cut notches in the plaster shell
around the edge that will be spliced to the other half and then
apply rubber and plaster to the other half. To prevent the
plaster sticking, coat the splice edge of the first half with
two coats of ordinary rubber cement.
RUBBER MOLDS
GUTTA-PURSHA MOLDS:
Purchase a sheet of GUTTA-PERCHA, about
one-fourth of an inch
thick. Cut it about size desired. Soak it in NAPTHA (which
causes it to swell), then soak it in hot water. This makes the
sheet of Gutta-Percha soft and mushy in appearance, somewhat
like a wet rag. Then in this condition, press it against your
model, slowly but firmly.
When there are small cavities such as the
mouth or eyes of a
figure, be sure that you get the rubber all the way in . . . the
better you press it, the sharper the mold will be.
Try it on a plaque first, for that can
be made in one piece
mold. When it is sufficiently pressed, have some plaster mixed
and pour it over the mold. This will harden quickly and so hold
your rubber mold (Gutta-Percha), in place until it gradually
dries out. It will then retain its shape. This plaster shell
should always be used to hold mold rigid while casts are being
made.
To make a mold of a figure in the round
(showing both sides) the
mold must be made in two pieces, with shell of plaster to hold
them in place, same a described previously.
