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PlatSil® Silicone Mold Rubbers
PlatSil® rubbers are platinum-cured (also known as addition-cure), room temperature-curing silicones that are used to make flexible, high-strength molds and parts. PlatSil® molds are often selected over other mold materials (e.g., polyurethane rubbers) because of their excellent release properties. They also exhibit long library life and low shrinkage on cure compared to other mold material options.
PlatSil® molds are excellent for casting polyurethane, epoxy and polyester resin, polyurethane foam, wax, plaster, soap, concrete, and more. Release agent is generally not needed to cast any of these materials.
These rubbers are commonly used in Sculpture & Foundry, Prototyping, Architectural Reproduction & Restoration, Foam, Plastic & Plaster Millwork & Ornamentation, Theming & Display, Candle Making, Craft & Hobby projects, and some Concrete Casting applications.
Looking for skin-safe PlatSil® Gel Silicones? Visit the PlatSil® Gel page.
View all product options within this series under "Product Options" below:
- Two-part platinum-cured (addition-cure) silicone rubbers
- Room temperature curing (RTV)
- Shore Hardness Options: A10-A60
- Do not exhibit shrinkage upon curing so they are useful for casting dimensionally stable parts for highly accurate prototyping and model making applications
- Molds do not require release agents when casting most materials
- Cured molds have a long library life
- Pourable or brushable (thicken with PlatThix liquid thickener or Fumed Silica)
- High-strength
- Excellent chemical resistance
- Reproduces fine details
- Can be accelerated for rapid cure
- Ideal for the most demanding resin casting applications
NOTE ON CURE INHIBITION: Sulfur/tin/amine-contaminated materials and tools will cause cure inhibition in platinum-cured silicone rubbers, which means that the rubber that is in contact with the contaminated surface will remain gummy or uncured. Make sure to test cure the rubber on your surface before full-scale application. Use a polyurethane or tin-cured silicone rubber if you know that you’ll be working with any of these inhibitors.
All individual PlatSil® products are listed below. Select an option to view additional product specifications and buying information:
PlatSil® FS-Series (Fast-Setting) Silicone Rubbers
Fast-Setting, High Performance Silicones
| Product | Mix Ratio by Weight or Volume | Shore Hardness | Pour Time | Demold Time | Cured Color |
| 1A:1B | OO60/A13 | 8 min. | 25 min. | Milky White | |
| PlatSil® FS-20 | 1A:1B | OO66/A20 | 8 min. | 25 min. | Milky White |
PlatSil® 71-Series Silicone Rubbers
| Product |
Mix Ratio by Weight |
Shore Hardness | Pour Time | Demold Time | Cured Color |
| PlatSil® 71-10 | 1A:10B | A10 | 5 min. | 30 min. | Pink |
| PlatSil® 71-11 | 1A:1B | A10 | 20 min. | 4 hr. | Blue-Green |
| PlatSil® 71-20 | 1A:1B | A20 | 25 min. | 4 hr. | Light Purple |
| PlatSil® 71-30 | 1A:10B | A30 | 60 min. | 24 hr. | Light Green |
| PlatSil® 71-35 | 1A:10B | A35 | 60 min. | 24 hr. | Blue |
| PlatSil® 71-40 | 1A:10B | A40 | 90 min. | 24 hr. | Translucent |
PlatSil® 73-Series Silicone Rubbers
Higher performance and lower in viscosity compared to PlatSil® 71-Series
| Product |
Mix Ratio by Weight |
Shore Hardness | Pour Time | Demold Time | Cured Color |
| PlatSil® 73-15 | 1A:1B | A15 | 20 min. | 4-5 hr. |
White Translucent |
| PlatSil® 73-20 | 1A:1B | A22 | 5 min. | 1 hr. |
Blue Translucent |
| PlatSil® 73-25 | 1A:1B | A25 | 15 min. | 4-5 hr. | Green |
| PlatSil® 73-29 | 1A:10B | A30 | 45 min. | 16 hr. | White |
| PlatSil® 73-40 | 1A:10B | A40 | 45 min. | 16 hr. | Yellow |
| PlatSil® 73-45 | 1A:10B | A45 | 40 min. | 16 hr. | Green |
| PlatSil® 73-60 | 1A:10B | A60 | 45 min. | 16 hr. | Blue |
Specialty PlatSil® Products
| Product | Mix Ratio by Weight | Shore Hardness | Pour Time | Demold Time | Cured Color |
|
A super-clear, glass-like rubber for a broken glass special effect |
1A:1B | A40 | 7 min. | 30 min. | Clear |
Looking for skin-safe PlatSil® Gels? Visit the PlatSil® Gel page.
| Softener | Add Silicone Fluid 50cSt to PlatSil products for a lower-viscosity mix and a softer rubber. |
| Thickener | Add PlatThix or Fumed Silica to thicken the liquid mix for application by brush or trowel. |
| Retarder | Add PlatSil® 71/73 Part R Retarder to slow the cure of PlatSil products. |
| Accelerator | Add PlatSil® 71/73 Part X Accelerator to accelerate the cure of PlatSil products. |
| Color Pigments | Use Silicone Color Pigments to color PlatSil® Silicone Rubber. Available in fleshtone, red, blue, green, yellow, black and white. |
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