making rubber molds from natural rubber latex
Fill a soft brush with soapy water and gently squeeze out the excess. The purpose of this is to make the brush easier to clean after using.
Dip the brush in our 1-P-5-B Mold-forming Compound and coat whatever model you are copying with this Vultex, being sure to cover all the crevices and not allow any air spaces to remain. If necessary, you may dilute the 1-P-5-B compound with a little water for the first coat only, to make sure that it flows into all the crevices. If any bubbles appear on the surface, blow gently on them and break them.
When the rubber appears set, which will probably be evidenced by a change in color or the rubber losing its milky cast which it has when wet, apply a second coat of 1-P-5-B and as many coats as necessary drying in the same way. Build up enough coats to make sure that you have a good film of rubber, say perhaps 1/8” to 1/4”. When the rubber mold is built up so that it would be sufficiently rugged for your purpose, allow the mold to dry overnight in a warm, dry place.
In the case of large flat molds, where an area of more than four square inches is involved, as in a large plaque, the coating is done by patchwork (small squares of the surface are coated and allowed to dry and then they are given additional coats. Small areas between the patchwork squares are filled in later. The purpose of this is to avoid shrinkage and resultant distortion in the object which is ultimately formed. If your object is very small, plan to coat it on all sides and not just the surfaces, as in plaque. An object that stands upright can be coated all over, provided a certain amount of Vultex is brushed down onto the surface on which the model stands, so that the shrinkage during drying will not cause the rubber to pull away from the base.
When finished, the mold is cut upon as much as is necessary to remove the model. If desired, the mold could be sliced into two even parts, each of the halves backed up with plaster when in use. The plaster used thus is known as a “mother” mold and is roughly shaped to fit the outside of the rubber mold. The finished rubber mold is treated on the inside with a glycerin and water mixture, or soapsuds, or mixture of zinc stearate and alcohol before it used to make plaster novelties, in order to prevent any sticking.
The brush may be easily cleaned with soap and water if this is done before the rubber has a chance to dry out. If the rubber dries out on the brush it will be necessary to clean it with kerosene or some similar solvent, followed by a washing in hot soapy water and a rinse in plain water.
The recommendations for use of this product are based on information which has been derived from the best available sources and laboratory tests believed to be reliable. However, there is no guarantee, expressed or implied, regarding the accuracy of this data or the results to be obtained. Nothing contained herein is intended as a recommendation to use our products so as to infringe any patent.