Description
This silicone mold rubber is a Shore 29A tin-catalyzed product known for its low viscosity, fast cure, and long library life. It does not require vacuum degassing and has a mix ratio of 100A:10B by weight. The working time is 45 minutes, and the cure time is 6 hours at room temperature. It is suitable for reproducing fine details in various industrial and art applications, such as making molds for prototypes, furniture, sculpture, and architectural elements. It can be used to cast materials like wax, gypsum, low melt alloys/metals, and urethane, epoxy, or polyester resins. However, it is important not to cast concrete into molds made with this product as it will not cure properly.
Features
- Fast cure time of 6 hours at room temperature
- Does not require vacuum degassing
- Low viscosity for easy mixing and pouring
Technical Properties
- Mix Ratio By Weight: 100A:10B
- Specific Gravity: 1.17 g/cc
- Specific Volume: 0.85 cm³/g (23.7 cu. in./lb.)
- Pot Life: 40 minutes
- Cure Time: 6 hours
- Color: Yellow
- Shore Hardness: 29 A
- Tensile Strength: 2.88 MPa (417 psi)
- 100% Modulus: 372 kPa (54 psi)
- Elongation @ Break: 361%
- Die B Tear Strength: 16.8 kN/m (96 pli)
- Useful Temperature Range: -54°C to 204°C (-65°F to 400°F)
- Dielectric Strength: 330 volts/mil
- Dielectric Constant, 100Hz: 3.29
- Dissipation Factor, 100Hz: 0.005
- Volume Resistance: 8.29E+11 ohm
- Volume Resistivity: 5.83E+13 ohm/cm
- Thermal Conductivity: 0.21 W/M*K
- Shrinkage: 0.002 mm/mm
- Mixed Viscosity: 10,000 cps
Instructions
Use in a properly ventilated area. Wear safety glasses, long sleeves, and rubber gloves to minimize contamination risk. Use vinyl gloves only, as latex gloves will inhibit the cure of the rubber. Store and use material at room temperature (23°C/73°F). Storing material at warmer temperatures will reduce the shelf life of unused material. These products have a limited shelf life and should be used as soon as possible.
Applying a Sealer / Release Agent
The rubber may be inhibited by sulfur-based clays, resulting in tackiness or a lack of cure. If compatibility is a concern, perform a small-scale test. Apply a small amount of rubber onto a non-critical area of the pattern. Inhibition has occurred if the rubber is gummy or uncured after the recommended cure time. To prevent inhibition, apply a “barrier coat” of clear acrylic lacquer onto the pattern and allow it to dry thoroughly. A release agent will make demolding easier. Ease Release™ 200 is recommended for making molds with silicone rubber and for releasing new silicone from cured silicone.
Measuring & Mixing
Materials should be stored at about 23°C (73°F). Wear safety glasses, long sleeves, and rubber gloves. Pre-mix Part A thoroughly to re-disperse fillers. Using a gram scale, dispense required amounts of parts A and B into a mixing container and mix for 3 minutes, scraping the sides and bottom of the container several times.
Pouring
Pour the mixture in a single spot at the lowest point of the containment field. Let the rubber seek its level up and over the model. The liquid rubber should level off at least 1.3 cm (1/2”) over the highest point of the model surface.
Curing & Performance
Allow the mold to cure fully (at least 6 hours) at room temperature before demolding. Post curing the mold for an additional 4 hours at 65°C (150°F) will eliminate residual moisture and alcohol. Allow the mold to cool to room temperature before using. Do not cure rubber where temperature is less than 18°C (65°F).
Accelerating Cure
Accel-T™ tin cure silicone rubber accelerator will accelerate the cure time. Note: working time is reduced in proportion to the amount of Accel-T™ added.
Thinning
Silicone Thinner™ will lower the mixed viscosity of tin cure or platinum cure silicone rubber products. It offers a lower mixed viscosity, better flow over intricate details, and increased pot life. However, ultimate tear and tensile are reduced in proportion to the amount of Silicone Thinner™ added. It is not recommended to exceed 10% by weight of the total system.
Making Brush-On Rubber Molds
Due to low viscosity, this product is not recommended for making brush-on rubber molds. Use Mold Max™ Stroke™ for this purpose.
Mold Performance & Storage
The physical life of the mold depends on usage. Casting abrasive materials can erode mold detail, while non-abrasive materials will not. Clean the mold with a soap solution and dry it fully before storage. Assemble multi-part molds and store them on a level surface in a cool, dry environment.
