Making Your Own Plastic (Interesting)

Hey All, I forgot about this one, but looking through past
accumulated articles on “How To”, I came across the following, which
might prove useful in many situations that I can think of around the
bench. Such As:

- Tool Handles
- Cast Originals
- Carving Substance
- Perhaps a substitute for Neillo (forgive the spelling)

And NO I have not tried it yet.


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

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."


I’m not allergic to sulphur -I don’t think I have an allergy to
anything anymore BUT…

Sulphur can easily catch fire. When it does so it releases SO2 -
Sulphur dioxide. This enters the lungs and dissolves in the bodies
fluids forming H2SO3 (sulphurous acid - not sulphuric) which causes

Wear a specialized mask and do it outdoors. Even a quick lungful is
awfully nasty.

Tony Konrath
Key West Florida 33040