Description
This translucent platinum cure silicone is mixed in a 1A:1B ratio by volume, eliminating the need for a weighing scale. It has a low viscosity, and vacuum degassing is not required for most applications. The silicone cures to a soft, strong rubber that is tear-resistant and exhibits very low long-term shrinkage. Molds made with this silicone are durable and suitable for casting wax, gypsum, resins, and other materials. It allows for an infinite number of color effects by adding silicone pigments or effects powders.
Properly cured, it complies with 21 CFR 177.2600 for use with dry food and aqueous food only. It is not intended for repeated use in contact with fatty foods.
Features
- Heat resistant up to 232°C (450°F).
- Suitable for casting low-temperature melt metal alloys.
- Will not cure against surfaces containing sulfur, even when sealed.
- Certified skin safe by an independent laboratory.
- Dry food safe and suitable for use with water/ice.
Technical Properties
- Mix Ratio By Volume: 1A:1B
- Mix Ratio By Weight: 1A:1B
- Pot Life: 20 minutes
- Cure Time: 3 hours
- Shore Hardness: 40A
- Specific Gravity: 1.12 g/cc
- Specific Volume: 0.89 cm³/g
- Color: Translucent
- Tensile Strength: 4.52 MPa (656 psi)
- 100% Modulus: 745 kPa (108 psi)
- Elongation @ Break: 500%
- Die B Tear Strength: 24.5 kN/m (140 pli)
- Useful Temperature (max): 232°C (450°F)
- Useful Temperature (min): -54°C (-65°F)
- Mixed Viscosity: 11,000 mPa·s
Instructions
Preparation
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. Mixing containers should have straight sides and a flat bottom. Mixing sticks should be flat and stiff with defined edges for scraping the sides and bottom of your mixing container.
Store and use material at room temperature (23°C/73°F). Warmer temperatures will drastically reduce working time and cure time. Storing material at warmer temperatures will also reduce the usable shelf life of unused material. These products have a limited shelf life and should be used as soon as possible.
Cure Inhibition
Addition cured silicone rubber may be inhibited by certain contaminants in or on the pattern to be molded, resulting in tackiness at the pattern interface or a total lack of cure throughout the mold. Latex, sulfur clays, certain wood surfaces, newly cast polyester, epoxy, tin cure silicone rubber, or urethane rubber may cause inhibition. If compatibility between the rubber and the surface is a concern, a small-scale test is recommended. 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 has passed. To prevent inhibition, one or more coatings of a clear acrylic lacquer applied to the model surface is usually effective. Allow any sealer to thoroughly dry before applying rubber.
Because no two applications are quite the same, a small test application to determine suitability for your project is recommended if performance of this material is in question.
Note: Even with a sealer, platinum silicones will not work with modeling clays containing heavy amounts of sulfur. Do a small scale test for compatibility before using on your project.
Applying A Release Agent
Although not usually necessary, a release agent will make demolding easier when casting into most surfaces. Ease Release™ 200 is a proven release agent for releasing silicone from silicone or other surfaces. Mann Ease Release™ products are available from distributors. Because no two applications are quite the same, a small test application to determine suitability for your project is recommended if performance of this material is in question.
Measuring & Mixing
Stir Part A and Part B thoroughly before dispensing. After dispensing required amounts of Parts A and B into the mixing container (1A:1B by volume or weight), mix thoroughly making sure that you scrape the sides and bottom of the mixing container several times.
Optional: Vacuum Degassing - Although not necessary, vacuum degassing helps eliminate any entrapped air in pourable silicone rubber. After mixing parts A and B, vacuum material at 29 inches of mercury, making sure that you leave enough room in the container for product expansion.
Pouring, Curing & Performance
Pouring - For best results, pour your mixture in a single spot at the lowest point of the containment field. Let the rubber seek its own level. A uniform flow will help minimize entrapped air. If using as a mold material, the liquid rubber should level off at least 1.3 cm (1/2”) over the highest point of the model surface.
Curing - Allow rubber to cure as prescribed at room temperature (23°C/73°F) before demolding. Do not cure rubber where temperature is less than 18°C (65°F).
Heat Curing - Time to demold can be reduced with mild heat. Example: After pouring, place the mold in a hot box or industrial oven at 60°C (140°F). This may reduce the demold time substantially. Note - time will vary depending on mold thickness.
Making a Brush On Mold? - This silicone can be thickened with a thickener for brush-on application and effects. Maximum recommended loading rate of the thickener is 2 parts (2% of part A). Do not use other silicones for brush on mold making.
Mold Performance & Storage
The physical life of the mold depends on how you use it (materials cast, frequency, etc.). Casting abrasive materials can quickly erode mold detail, while casting non-abrasive materials (wax) will not affect mold detail. Before storing, the mold should be cleaned with a soap solution and wiped fully dry. Two-part (or more) molds should be assembled. Molds should be stored on a level surface in a cool, dry environment.
