Description
SORTA-Clear™ 18 silicone rubber is a water-clear, translucent material with a platinum catalyst that cures at room temperature with minimal shrinkage.
It offers high tensile and tear strength, making it suitable for molds where visibility is crucial. It can be used with urethane, epoxy, or polyester resins without a release agent and can be pigmented with silicone pigments.
It is food safe for culinary applications and skin safe, certified by an independent laboratory.
Technical Properties
- Mix Ratio By Weight: 100A:10B
- Working time: 60 minutes
- Cure Time: 24 hours
- Shore Hardness: 18 A
- Specific Gravity: 1.08 g/cc
- Specific Volume: 0.93 cm³/g
- Tensile Strength: 2.93 MPa
- 100% Modulus: 241 kPa
- Elongation @ Break: 545%
- Die B Tear Strength: 14.0 kN/m
- Color: Water Clear Translucent
- Useful Temperature (min): -54°C
- Useful Temperature (max): 232°C
Instructions
Safety
Use proper ventilion. Wear safety glasses, long sleeves, and vinyl gloves. N.B. latex gloves will inhibit the cure of the rubber.
Storage and Usage
Store and use at room temperature (23°C). Warmer temperatures reduce working and cure time.
Storing at cooler temperatures will extend the shelf life.
Cure Inhibition
Inhibition may occur with contaminants like latex, tin-cure silicone, sulfur clays, and certain wood surfaces. Test compatibility on a non-critical area.
Seal the object with a clear acrylic lacquer to prevent inhibition. Allow the sealer to dry before applying the rubber.
When in doubt, a small test application to determine suitability for your project is recommended.
When working with modeling clays that contain heavy amounts of sulfur, even a sealer will not suffice. Do a small scale test for compatibility before starting your project.
Applying A Release Agent
The use of a release agent is usually not necessary, but will help with the ease of demolding. Use Ease Release™ 200. Spray the object once, then brush lightly over the surface, spry once more lightly and let dry for 30 minutes.
Test on an identical surface if unsure.
Measuring & Mixing
Pre-mix Part B thoroughly.
Disperse the prescribed amounts of Parts A and B in a mixing container and mix for 3 minutes. Make sure to scrape sides and bottom of the container repeatedly.
Vacuum degassing is recommended to remove air. Vacuum until material rises and implodes, then vacuum for 1 minute more.
Pouring
Pour the mixture at the lowest point of the mold. Let it level at least 1.3 cm (1/2 inch) over the highest model point.
Curing
Allow to cure fully at room temperature (23°C) for 24 hours. Do not cure below 18°C. Mild heat can reduce demold time but may darken the rubber.
Post Curing
Post curing enhances properties. After room temperature curing, expose to 80°C for 2 hours and 100°C for 1 hour. Cool to room temperature before use.
Using The Mold
New molds have natural release characteristics. No release agent is needed for wax or gypsum. Use Ease Release™ 200 or a similar product for polyurethane, polyester, and epoxy resins to extend mold life.
Mold Performance & Storage
The mold's life depends on it's use. Abrasive materials like concrete erode detail faster. Clean the molds with a soap solution and dry them before storage. Assemble multi-part molds before storage and keep them on a level surface in a cool, dry place.
