Moldsil-100 – High Performance Silicone Rubber for Mold making

Product Description

Moldsil-100 is a premium grade condensation curing type medium viscosity Silicone RTV, recommended for mold making applications. This is a lowable grade, having high mechanical strength and cures with various catalyst options (depending on the application requirements) at room temperature to a flexible elastomer, well suited for detailed and exact reproduction of artifacts, figures, architectural items and similar
bjects. Moldsil-100 will reproduce the finest detail of the master and is suitable for a variety of art related and industrial applications such as mold making for reproducing prototypes, furniture, architectural items and sculptures.

Moldsil-100 can also be thickened with Thixopol 88 additive for brush-on type applications for reproducing vertical surfaces.

Product Features

  • Flowable type high strength silicone rubber curing at room temperature – Excellent detail reproduction
  • Good mechanical properties - leading to long service life
  • Highly elastic and excellent release properties – for easy de-molding
  • Excellent chemical resistance – compatible with most molding materials with long service life
  • Vertical surface replication with the use of a Thixotropic additive Thixopol 88


  • Moldsil-100 offers a good combination of good flow, high mechanical properties and excellent detail reproduction with good service life in mold making applications
  • Moldsil-100 is compatible with several master materials such as wood, metal, plastics, rubber, clay...
  • Molds made of Moldsil-100 can be used to cast a variety of reproduction materials such as polyester resins, polyurethanes low melt metal alloys, epoxies, wax, gypsum, clay, concrete …..
  • Moldsil-100 is well suited for pad printing applications used in printing curved surfaces

Technical Overview

Uncured Properties

Property Standerd Units Valus
Colour White
Viscosity Component A m.Pa.s 20000
Specific Gravity ASTM D-1475 1.07
Mixed Viscosity ASTM D-2393 m.Pa.s 15000
With 5% CAT-1 ASTM D-2471 Min. 110
With 5% CAT-9 ASTM D-2471 Min. 45
With 5% CAT-15 ASTM D-2471 Min. 20

Cured Properties *(With 5% CAT- 9)

Property Standerd Units Valus
Hardness ASTM D-2240 Shore A 14
Tensile ASTM D-412 MPa 4.2
Elongation ASTM D- 412 % 550
Tear Strength ASTM D-624 N/mm 20
Linear Shrinkage % <0.5

*Typical Properties, should not be used as specification

Catalyst Options

Moldsil-100 can be cured in to elastomeric products using the following cure options:

  • CAT-1 : General purpose catalyst with long work life for slow demolding
  • CAT-9 : Fast demolding catalyst with short work life for fast demolding

Catalyst Properties

Property CAT -1 CAT -9
Colour Transparent Transparent
Density (g/cc) 0.95-0.97 0.95-0.97
Viscosity (m.Pa.s) 25 25
Mix Ratio (A:B) 100:5 100:5

Method Of Use

  • Surface Preparation: The master surface should be clean, free of loose materials and dust particles. With porous substrates use a suitable release agent such as petroleum jelly or soap solution.
  • Mixing of Components: Thoroughly stir Moldsil-100 before use, as filler separation might have occurred during prolonged storage. Select a container for mixing which is 4-5 times larger than the total material to be mixed. Weigh the A and B components in the desired ratio (ex: 100:5). Stir vigorously for several minutes scraping the sides and the bottom of the container to produce a homogeneous mix. Hand or mechanical (power) mixing can be used but do not mix for an extended period of time to avoid entrapping large amounts of air or causing over heating resulting in shorter work life.
  • De-aeration : It is recommended that entrapped air be removed under vacuum to eliminate voids in the final product. This process will make the mixture to expand and then collapse. A volume increase of about 4-5 times will occur during the de-aeration process. Therefore, a large container should be used to accommodate this volume change. It should be also noted that prolonged application of vacuum will remove the volatiles from the mixture that can result in poor cure.
  • This system is sensitive to temperature and humidity and therefore can influence the cure speed. However, the final mechanical properties of the mold will be attained in one week. The material will cure to a flexible rubber within 24 hours at room temperature and the mold can then be separated from the master
  • Pouring the Mix and Curing: The mix should be poured as soon as possible on to the original master to avoid air entrapment. The material will cure at a speed depending on the selection and the amount of the catalyst.

Handling Precautions And Safety

Moldsil-100 contains constituents that have been found to be safe. Hence special handing precautions except general industrial hygiene need to be followed. Catalysts (CAT-1 and CAT-9) contain organo-tin compounds and are flammable and might cause irritation upon contact with eyes and skin. Adequate protective measures are recommended. Refer to Material safety Data Sheet (MSDS) for safe use of the product

Usable Life And Storage

The shelf life of Moldsil-100 and the catalysts (CAT-1 and CAT-9) is 6 months from the date of manufacturing if stored below 27o C in original unopened containers.


Moldsil-100 is available in following kit forms :

  • Kit of 5.25 kg (5 kg Moldsil-100 + 250 grams of CAT-1 or CAT-9)
  • Kit of 1.050 kg (1 kg Moldsil-100 + 50 grams of CAT-1 or CAT-9)


This product is neither tested nor claimed as suitable for food contact, medical or pharmaceutical applications.