Product Description
SMOOTH-SIL 940
Smooth-Sil™ Platinum silicones cure at room temperature with minimal shrinkage. Highly versatile, these silicones are suitable for creating molds of any size, from small to large production molds. They offer excellent chemical, wear, and heat resistance. Materials such as plaster, concrete, wax, low-melting metals, or resins (urethane, epoxy, or polyester) can be cast into Smooth-Sil™ 940 without a release agent. The pot life is 30 minutes, and full cure occurs in 24 hours at room temperature.
Smooth-Sil™ Platinum silicones are ideal for rapid prototyping, wax casting (for foundries and candle makers), architectural restoration, and concrete casting. Smooth-Sil™ 940 is also food-safe for culinary applications.
Features
- Room-temperature cure
- High tear strength
- High heat resistance
- Low shrinkage
- No release agent required
Applications
- Food-safe mold making
- Prototyping
- Mold production
- Wax and plaster casting
- Compatible with most casting resins (urethane, polyester, epoxy)
Hardness (ShoreA) | 40 |
Mixing Ratio (by weight) | 100A : 10B |
Pot Life | 30 min |
Curing Time | 24 h |
Heat resistance (min) | -53 °C |
Heat resistance (max) | 232 °C |
Shrinkage | <0.0254 mm/mm |
Viscosity (cP) | 35 000 |
Tear strength (N/mm) | - |
Tensile strength (N/mm²) | - |
Elongation (%) | 300 |
Color | Light Pink |
Usage Instructions
Mix both components thoroughly, as they may separate during storage. Measure A and B by weight or volume in a 1:1 ratio and mix for at least 3 minutes, scraping container sides and bottom to ensure even curing.
Remove air bubbles by vacuum degassing (pump ≥1 bar). Allow silicone to expand and collapse fully before pouring into the mold.
Pour silicone slowly from the lowest point, filling gradually to avoid bubbles.
Cure at room temperature (23 °C) for at least 6 hours. Avoid curing below 18 °C. Cure time can be shortened with mild heat (e.g., 60 °C oven).
Inhibition: Certain materials (latex, tin-cure silicones, sulfur-rich clays, some woods, new polyester casts, epoxy, and urethane products) may inhibit platinum silicone curing. Test compatibility if unsure. Coating the model with clear acrylic can prevent inhibition.
Safety
Use in well-ventilated areas. Wear safety glasses, long sleeves, and vinyl gloves (latex gloves may inhibit curing). Store and use at room temperature (~23 °C). Higher temperatures shorten working and curing times. Use promptly; product has limited shelf life.