1. Stir the base (Part A) well before use (except when machine dispensing).

2. Weigh the desired amount of base into a clean mixing container. Tip the container and roll the base all the way around the

side-wall up to two inches from the top. This will prevent the catalyst from becoming absorbed into the container. It is recommended that the container be filled to not more than 1/3 the container depth to allow sufficient room for expansion during the de-aeration procedure.

3. Weigh the proper amount of catalyst into the container. Mix the base and catalyst together by stirring with a stiff, flat ended metal spatula until a uniform color is obtained. Scrape the container walls and bottom well to insure a thorough mix.

4. Place the container into a vacuum chamber and evacuate the entrapped air from the mixture using a vacuum pump capable of achieving 29 inches of mercury vacuum. The mixture will rise, crest and then collapse in the container. Interruption (bumping) of the vacuum may be necessary to prevent overflowing the container. Keep the mixture under full vacuum for 2-3 minutes after the material has receded in the container.

5. Bleed air slowly into the vacuum chamber. When the chamber is at atmospheric equilibrium, remove the cover plate and take out the container.

6. Pour the deaired material slowly in a steady stream from one end of the mold box so that the material flows evenly over the pattern. This should minimize entrapment of air bubbles under the flowing material. A "print" coat may be poured first over the pattern which will also help reduce the possibility of entrapping air on the pattern and in the cured rubber. A mold release (petroleum jelly) may be applied on the pattern first to improve release.

7. Allow the rubber to cure for 16-24 hours at 75±5°F (24°C) before removing the cured rubber mold from the pattern. For best results, allow the mold to air cure an additional 24 hours before using it in production. Full cure is achieved in 3-7 days.



1. For best results, mix and cure the material at 75°F (24°C) and 50% relative humidity.

2. Higher temperature and humidity will decrease the work life and pot life of the material. The faster cure will also affect the flow properties. Refrigeration of the base prior to use in hot environments has shown to improve the handling properties of this material.

3. Lower temperatures and humidity will increase the work life and pot life of the material. The slower cure will increase the flow time. Cure temperatures below 68°F (20°C) are not recommended and have been found to cause a reduction in final cure hardness and properties.

4. It is important that the catalyst containers are tightly closed after use to prevent contamination.

SILBIONE RTV 4044 A may be stored for up to 18 months from its date of manufacturing.Please consult the Safety Data Sheet of this product.


SILBIONE RTV 4044 is a 1:1 mix ratio, two-component clear, high strength, addition cure silicone rubber compound. It is formulated to cure overnight at room temperature or within hours at elevated temperature to give a hardness of approximately 38 ShA. Its low viscosity makes the product easy to pour and quick to degas.

SILBIONE RTV 4044 is designed to serve the needs of the prototyper by reproducing intricate details and maintaining tight tolerances. In addition, SILBIONE RTV 4044 has been formulated to provide improved urethane resin resistance.

2 Part RTV

  • Conventional production and prototype molds
  • Finished rubber parts
  • Stereolithography (SLA) molds
  • Low temperature molding and overmolding

North America












pot-life_0d649a54-7503-4c7c-a047-9d0c4b3e9f6apot-life_0d649a54-7503-4c7c-a047-9d0c4b3e9f6aPot life2.125PairedMixASTM C 603hrs
hardness_cd523e03-72a3-4261-93f9-36f7bbeeafb1hardness_cd523e03-72a3-4261-93f9-36f7bbeeafb1Hardness39PairedMixASTM D 2240sh.A
elongation_68a5ddf2-2baf-4e60-ac6f-0a8a18a758b2elongation_68a5ddf2-2baf-4e60-ac6f-0a8a18a758b2Elongation> 280PairedMixASTM D 412%
tear-strength_a14604f3-602f-4240-a9bf-15d90bbfbd13tear-strength_a14604f3-602f-4240-a9bf-15d90bbfbd13Tear strength> 100PairedMixlb/in





SILBIONE RTV 4044 BSILBIONE RTV 4044 B/our_offer/Product/90061046/90061045/SILBIONE-RTV-4044-B