Thursday, December 6, 2007

FLEXIBLE MOLD COMPOUND

FLEXIBLE MOLD COMPOUND

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.

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