MAKING YOUR OWN PLASTIC MOLDED OBJECTS

MAKING YOUR OWN PLASTIC MOLDED OBJECTS

SULPHO-PLASTICS

This plastic is particularly adaptable for making molds and

light castings requiring tensile strength but very clear

outline. It may also be used for making ornaments and

novelties. However, as this is flammable, do not use for

ashtrays.

While the name would convey the thought of plastic sulphur which

is an unstable allotropic form of sulphur, this is not the case,

as the sulphur acts as a bond to hold the filler together and

forms a stable material.

Interesting marble effects may be obtained by varying the filler

used; and by substituting a small quantity of chalk to replace

some of the graphite, a very pleasing glazed surface marble is

formed.

As long as the graphite is retained as a filler, this plastic

may be electroplated and forms a very economical base for such

work.

FORMULA: Mix thoroughly and smoothly together 25 parts of

GRAPHITE and 75 parts SULPHUR and place over heat. As soon as

the mass has melted and runs like water, remove from the heat.

In any case, a temperature of 235 degrees F. not be exceeded.

If heated about 250 degrees F. the plastic will form a rubbery

mass and will have to be cooled and reheated. In this liquid

state the plastic is ready for casting and may be poured into

smooth surfaced molds.

N.B. to heat this mixture properly, a good even heat is

necessary. Should the heating be done by flame, the container

should be placed in a sand bath to insure an even heating

surface. The cast-iron top of a heater or stove is excellent.

EQUIPMENT: The only equipment for the above that is required is

space enough to work in, a stove or heater, a pan to heat the

mixture in and a bench or table.

PROCEDURE: Before making any casting you will need a pattern.

After choosing a design that fits your need, your next step is

to make the mold. Then you may start into production. If your

product requires any holes, threads or machining, this may be

done in the same manner as in working with a metal casting.

Always think of your castings as metal, for they have metallic

properties, i.e., conduct heat, electricity and can be

electroplated. In fact, the most valuable quality of

Sulpho-Plastic is the fact that it can be used as a metal

substitute. This permits you to make products that look and are

as good and even better, in some cases, than a true metal. For

instance, to make a chrome plated metal lamp base or other metal

casting would require foundry equipment and machine shop work

and in all, a process miles out of the reach of the small

manufacturer. However, with our plastic, a lamp base, similar in

all respects, may be made for a fraction of the other cost.

ELECTROPLATING: While this can be done at home with very little

equipment, it is advisable to have it done by a commercial

electroplater, who does it very cheaply and much more

efficiently. Electroplating is only used on expensive replicas

and is not advisable for a start.

DESIGN: The number and variety of articles that can be

manufactured from Sulpho-Plastic is practically unlimited and to

make a complete list would be impossible. However, any article

of reasonable size and simplicity of design such as lamps,

curios, buddhas, incense burners, elephants, vases, plaques,

brooches, desk-sets, toys paper weights, etc., may be cast by

using an original or purchased article for a pattern or model -

or an original design may be patterned in clay and used to make

a mold. It is advisable for the beginner to choose a simple

article for a start, preferably solid, such as paper weights or

book-ends.

MOLDS: Molds may be made of metal or plaster of paris. Metal

molds, however, require a great deal of skill and equipment to

produce. Therefore for the beginner, it is advisable to use

plaster of paris.

To make plaster of paris molds; first obtain a box, wood or

cardboard will do; about an inch longer each way than the

article to be cast. Coat the inside of the box very thoroughly,

yet thinly, with stearine or sweet oil. Use this also on the

article to be cast. This acts as a lubricant and the plaster of

paris will not cement itself to either the box or the article,

if the oil is evenly distributed.

Now, next make a thick, creamy mixture of plaster of paris by

sifting the plaster gradually into the water, stirring

constantly to prevent lumping. Let this stand a few minutes to

allow the air bubbles to escape. Pour mixture slowly over

pattern in this box to about double the thickness of the pattern.

Allow several hours to dry, then remove. If the stearine or

sweet oil was applied properly, this will be easy. When the

mold is thoroughly dry, give it a coat (thin) of shellac and

repeat in 12 hours. Mold is now ready for use.

MOLDING: First and foremost always make sure that you have

lubricated your mold with beeswax or stearine. Place molds on a

reasonably level surface and pour the sulpho-plastic into the

mold, quickly and smoothly. Do not pour from a height as this

will break the lubricant and leaves blemishes on the casting.

Plastic must be poured quickly to prevent cooling in folds and

thus making a poor casting. One of the big assets of

sulpho-plastics is the fact that it dries and hardens almost

immediately. There is no long wait for casting to dry.