Recommended
Silicone casting rubber 1:1 Shore 40 (transparent)
At a glance
- Hard silicone rubber
- Type: platinum cure
- Food-safe
Fast delivery throughout Europe
Secure payment with PayPal, Mastercard, Visa and more
4.7 out of 5 stars on Trusted Shops
Transparent silicone casting rubber (Shore 40) is a fully clear casting rubber that is ideal for applications where optical transparency is required. This silicone casting rubber is particularly suitable for potting and protecting electronics, sensors and printed circuit boards, as it forms a clear, flexible and insulating layer after curing. It is also widely used for prototyping, technical components, LED encapsulation and other applications where visibility of the encapsulated object is important.
Please note: transparent silicone rubber is less suitable for making epoxy moulds that are used multiple times. Prolonged exposure to epoxy can cause the silicone rubber to yellow or develop a white haze. In such cases, the semi-transparent silicone rubber can be used instead.
Benefits of transparent silicone casting rubber Shore 40
- Transparent.
- High tensile strength.
- Stiff (Shore 40).
- Simple 1:1 mixing ratio.
- Food-safe.
Processing silicone casting rubber
Silicone casting rubber is easy to use thanks to its 1:1 mixing ratio. Follow the steps below for perfect results.
- Accurately weigh the base (component A) and hardener (component B) using a scale in a 1:1 mixing ratio.
- Mix both components thoroughly for approximately 3 minutes (not too vigorously) using a mixing spatula. Make sure to scrape the sides and the bottom of the mixing cup well. Then pour the mixture into a new mixing cup and mix thoroughly once again.
- The silicone casting rubber is now ready for use. The working time is approximately 45 minutes and the recommended processing temperature is 20 °C. At higher temperatures, curing will occur more quickly, giving trapped air bubbles less time to escape. At lower temperatures, curing will take longer.
-
After approximately 8 hours, the silicone casting rubber will be tack-free.
Please note: due to its high viscosity, the casting rubber is relatively thick and therefore more difficult to degas. To remove air bubbles, we recommend using a pressure pot during curing. In addition, the high viscosity may make weighing and mixing slightly more challenging.
Properties
| Set | Base (SR1-40A-T) | Curing agent (SR1-40B-T) |
| 2 kg | 1 kg | 1 kg |
| 6 kg | 3 kg | 3 kg |
| 20 kg | 10 kg | 10 kg |
| 200 kg | 100 kg (10 x 10 kg) | 100 kg (10 x 10 kg) |
| 400 kg | 200 kg (drum) | 200 kg (drum) |
Hardness: Shore 40 (hard)
Specific gravity: 1.02 kg/dm3
Volume: 1 litre of silicone rubber equals 1 kilo
Colour: transparent
Temperature resistance: 200 ℃ continuous, 300 ℃ short-term
Working time: 45 minutes
Curing time: 8 hours (tack-free)
Shelf life: 2 years (in unopened packaging)
Food-safe: yes
Product properties
The key technical properties clearly listed in one place.
- Article number
- SIL001978
-
The technical product category, such as primer, resin, hardener or cleaner. It explains the product's purpose and helps you find other products with a similar function.
- Silicone casting rubber, Platinum Cure RTV-2
-
Mixing ratio indicates how much of each component is needed, for example resin (A) and hardener (B). A ratio of 100:50 by weight means 100 grams of A to 50 grams of B; by volume you might use millilitres. Weight and volume ratios are not necessarily the same because the components may have different densities. Accurate measuring is important for proper curing.
- 1:1
-
Hardness describes a material's resistance to indentation. For silicone rubber and other elastomers, the Shore A scale is commonly used: Shore A 15, for example, is softer than Shore A 40. Harder plastics may be rated on the Shore D scale. The number belongs to its Shore scale and is not a unit like MPa; values on different scales cannot be directly compared.
- Shore 40
-
Density describes the mass of a material per unit volume. Values may be given in g/cm³, kg/L or kg/m³; 1 g/cm³ equals 1 kg/L. For example, one litre of a liquid with a density of 1.2 kg/L weighs approximately 1.2 kg. Density helps convert between weight and volume, but it can vary with temperature.
- 1.02 kg/dm³
-
The period for which an unopened product remains usable under the specified storage conditions. Check whether the period starts from the manufacturing date or another date. Shelf life may be shorter after opening, especially for products sensitive to air or moisture.
- 24 months
-
Working time is the period during which a product remains workable after mixing or activation, usually given in minutes at a specified temperature, often 20 °C. With reactive resins, the chemical reaction also continues in the mixing container, and larger quantities or higher temperatures can shorten this time. Working time is different from gel time and full curing time.
- Approximately 45 minutes (at 20 °C)
-
Food contact suitability means that a material may come into contact with food under specific, defined conditions. This suitability does not automatically extend to every application.
- Food type: for example water-based, acidic or fatty foods.
- Contact time and temperature: brief contact may have different requirements from long-term storage or contact with hot food.
- Processing: correct mixing ratio, full curing and any required post-curing may be conditions of approval.
A fully cured or odourless product is not automatically food-safe. Check the manufacturer's declaration or technical documentation for the permitted use.
- Yes
-
Heat resistance describes the temperature a material can withstand after correct processing and curing, usually expressed in degrees Celsius (°C). Continuous exposure is different from a brief temperature peak, and mechanical loading may also affect the limit. Heat resistance is not the same as the temperature at which the product can be applied.
- Up to 200 °C (short-term up to 300 °C)
- Suitable for 3D-printed moulds
- Yes (tested with PLA, PETG, ASA, ABS and PVB)
- Colour
- Transparant
Reviews
Frequently bought together
Useful additions for your project.
Recommended
