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Considerations for this method


  • Resilient once cured
  • Can be colored with special pigments


  • Incompatible with some materials (chemically inhibiting the curing process)
  • Requires degassing in vacuum chamber for maximum clarity
  • Mixture ratio 10:1 must be carefully measured


Material options

 METHODMATERIALCOST ($/cubic inch)TIME: totalProduction StepsTime requiredSpecial Equipment NeededConditionsAble to be colored?health and safetyChemical CompositionPPEWhere to Purchase

Without Vacuum ChamberSORTA-Clear 40$0.8016.5 hours (30 minutes preparation and 16 hours cure time)Measure each component of the 2-part product into mixing container as specified by manufacturer's instructions.
Stir thoroughly to combine two components.

Pour into the lowest point of the model/mold to avoid trapping air bubbles. A thin stream poured slowly from high above may help to remove small air bubbles not collapsed by vacuum chamber.
Allow 16 hours for substance to cure before handling.
Pot life is 60 minutes. Cure time is 16 hours, regardless of volume. Curing can be accelerated by applying mild heat (up to 60º C). PRODUCT WILL DARKEN CONSIDERABLY IF HEATED.Scale to measure the two components by weight accurately.
Large, clean mixing container and stir stick.

Product is a platinum-cure silicone rubber, and is incompatible with materials bearing platinum-cure inhibitors. Will not cure if ratio of two components is not accurately measured.Yes.
Add a small amount of Silc Pig™ color pigment to Part A and mix thoroughly before combining with Part B.
Part A: No data on possible toxicological effects available.
Part B: No data on possible toxicological effects available.
UnlistedVinyl gloves to limit skin contact, splash goggles to prevent contact with eye.
(latex gloves will inhibit cure of the product)
Reynolds Advanced Materials

With Vacuum ChamberSORTA-Clear 4017 hours (1 hour preparation and 16 hours cure time)

See above, after measuring and mixing the two components, degas the mixture using a vacuum chamber. (Mixing container must be at least 4 times the volume of the combined components, as the gas expands and may over-flow the container.)

Then follow remaining steps, above.

In addition to above, a vacuum chamber to degas the mixed substance before it is poured into mold/model.



Mold preparation