Making Molds with Natural Latex

HX-80 (Natural Latex)

A time-tested formula which has been used by mold makers the world over.

HX-80 is a vulcanizeable Natural Latex compounded from specially processed Latex with a high solid content, which minimizes shrinkage.  HX-80 is therefore suitable for making rubber molds by painting, brushing or spraying.  The special method of compounding, and its high solid content, permit reproduction of the finest detail.  It's major uses have been in the manufacture resin figures, ornamental wax candles, and isostatic molding bags.

HX- 80 also has the following additional characteristics:

  • High Latex stability and long storage life
  • Films that are very tear-resistant
  • Excellent resistance to aging & sunlight
  • Exceptionally long runs while casting concrete, plaster, waxes and certain metals
  • Continuous uniform batches made under strict quality control
  • Shrinkage is minimal


HX-80 is preserved with ammonia, and has a distinct ammonia odor to it.

HX-80 also has a distinct thickening agent called CECO Powder.  This powder has been developed after many years of research.  In addition to thickening the Latex without clumping, CECO Powder helps improve the strength of the rubber as well as its resistance to degradation by the casting materials.



HX-80 is a formulation compounded from a specially prepared high solids content natural latex. It is of the vulcaniseable type.  This means that after you have completed the buildup of coats on your model, heat or time must be used to bring about the final cure.


Vulcanisation is the process of causing the Latex to complete its final process of cross-linking.  This can be accomplished by either time or heat. The time recommended is approximately 3 days at room temperature.  If heating is chosen, it is recommended that you heat the completed rubber mold on the model for approximately four hours at 120 degrees Fahrenheit.


In testing for Vulcanisation, the following procedure is usually advisable: After being certain that the Latex is not tacky, take a sharp object and make a small indentation in the Latex.  It should spring back within an hour.  Only a small fraction of the indentation should remain.  If more than a small fraction remains, then heat the Latex for about another hour.  This should be sufficient to bring about the total cure.


HX-80 is approximately 64 percent solids.


HX-80 is compounded with ammonia. It has a distinct ammonia odor.  Ammonia is one of the most common preservatives used in Latex when it is shipped from the plantation.



  • High latex stability.
  • Long storage life.
  • Vulcanized molds have excellent resistance to tearing.
  • Excellent resistance to sunlight and aging.
  • Uniform batches made under strict quality control.


All latex has a tendency to shrink. HX-80, however, because of its high solids content, shrinks very little.  When making your model, an allowance for shrinkage should be made.


HX-80 has a shelf life of approximately one year if kept in a cool place.  The Latex will turn into a cottage cheese consistency when it is spoiled or will develop a putrid odor.


HX-80 is the old standby of the following industries:

  • Plaster

Our HX-80 Latex has been used by those who pour plaster since the end of World War II.  It has great resistance to the heat that is generated by the Plaster and maintains excellent detail.  The ingredient characteristics of this Latex are such that no release agent is needed when casting plaster.

  • Concrete

HX-80 has also been used by those who pour concrete since the end of World War II.  Very long runs have been obtained by producers of Lawn and Garden Ornaments and similar items made from concrete.

  • Wax

HX-80 has good resistance to the heat generated by wax.  Although it cannot be used for exceptionally long runs, short and medium size runs work out very well.

  • Polyester Resins

HX-80 can be used when pouring polyester Resins, but only with limited success.  If the Latex is properly vulcanized, runs of between twenty and fifty pieces with polyester resins can be obtained.  It is important to vulcanize the Latex properly when working with polyester resins.  If this is not done, the heat generated by these resins, as well as several side chemical reactions, will cause a rapid degradation of the Latex.


HX-80 is a milky white, or sometimes slightly grey, compound of medium viscosity.