Description
This water-clear urethane casting resin is designed for applications requiring clarity.
Crystal Clear™ 202 features low viscosity for easy mixing and pouring, curing at room temperature with negligible shrinkage.
The cured castings are UV-resistant and non-brittle, allowing vibrant colors and effects when pigments are added.
Features
- UV Resistant
- Not brittle
- Vibrant colors are achievable with pigment dispersions
Applications
- Encapsulation
- Prototype models
- Lenses
- Sculpture reproductions
- Decorative cast pieces
- Jewelry
- Special effects
- Props
Technical Properties
- Mix Ratio By Weight: 100A:90B
- Pot Life: 9 minutes
- Cure Time: 90 minutes
- Shore Hardness: 80 D
- Specific Gravity: 1.036 g/cc
- Specific Volume: 0.97 cm³/g
- Color: Clear
- Tensile Strength: 24.13 MPa
- Elongation@Break: 10%
- Compressive Modulus: 303.42 MPa
- Heat Deflection Temp: 49°C
- Flexural Strength: 37.15 MPa
- Flexural Modulus: 1,263.76 MPa
- Compressive Strength: 28.96 MPa
- Tensile Modulus: 594.42 MPa
- Shrinkage: 0.0125 mm/mm
- Index of Refraction at 20°C: 1.49888
- Index of Refraction at 25°C: 1.49893
- Mixed Viscosity: 600 mPa·s
Instructions
Safety
Store and use at room temperature (23°C). These products have a limited shelf life and should be used as soon as possible.
Environmental humidity should be as low as possible. Good workshop ventilation is essential. Wear safety glasses, long sleeves, and rubber gloves to minimize the risk of contamination.
Wearing a NIOSH-approved respirator will minimize inhalation of residual fumes. Use in a low-humidity environment (below 50% RH).
Mixing
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. Liquid urethanes are moisture sensitive and will absorb atmospheric moisture.
Mixing tools and containers should be clean and made of metal or plastic. Materials should be stored and used in a warm environment (23°C/73°F).
Stir or shake Part B thoroughly before dispensing. The proper mixing ratio is 100A:90B by weight. You must use an accurate digital gram scale to properly weigh Parts A and B.
Do not use an analog scale or attempt to measure components by volume.
Dispense the required amount of Part A into a mixing container. Weigh out the appropriate amount of Part B and combine with Part A. Mix SLOWLY but thoroughly for at least 90 seconds, making sure to scrape the sides and bottom of your container several times. If coloring or filling the product, add filler or pigment dispersion to Part B and mix thoroughly before adding Part A.
Pouring
If casting into a rubber mold, pour the mixture into a single spot at the mold's lowest point. If encapsulating an object, do not pour the mixture directly over the object. Let the mixture seek its level. A uniform flow will help minimize entrapped air.
Curing
Castings will reach ultimate physical properties at room temperature in 7 days. Castings removed from the mold before the recommended cure may exhibit a tacky surface that can be eliminated by exposing the casting to 65°C for 6 hours.
Working time and cure time depend on mass concentration and mold configuration.
Post-curing is recommended for thin or low-mass-concentration castings.
Castings should be post-cured in a mold or support structure. Post-cure Schedule: Allow the material to cure fully at room temperature, then heat for 6 hours at 65°C–72°C. Allow casting or part to cool to room temperature before demolding.
Storage
IMPORTANT: The shelf life of the product is reduced after opening. The remaining product should be used as soon as possible. Immediately replacing the lids on both containers after dispensing product will help prolong the shelf life of the unused product.
XTEND-IT™ Dry Gas Blanket (available from Smooth-On) will significantly prolong the shelf life of unused liquid urethane products.
Warnings
CAUTION: NOT FOR HOME USE. THIS PRODUCT IS FOR INDUSTRIAL USE ONLY. With adequate local exhaust ventilation, respiratory protection is not normally required when using this product. Where risk assessment shows air-purifying respirators are appropriate, follow OSHA respirator regulations and European Standards EN 141, 143 and 371. Protective clothing (gloves and long sleeves) is required to minimize the risk of dermal sensitization. If breathing is affected or a dermal rash develops, immediately cease using this product and seek medical attention. Read SDS before using.
