| 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. |
