Silicone casting rubber 1:1 Shore 25

RESION Silicone Casting Rubber Shore A25 is a platinum-cure RTV-2 silicone rubber designed for producing slightly flexible moulds for a wide range of applications. The silicone rubber is strong, dimensionally stable, food-safe and produces moulds with excellent durability and outstanding detail reproduction.

Thanks to its simple 1:1 mixing ratio, this platinum silicone is easy to use and suitable for both beginners and experienced users. Shore A25 Silicone Casting Rubber is recommended for applications where a slightly firmer mould is required, while still remaining flexible enough to allow easy demoulding without damaging the cast. This type of silicone is particularly suitable for producing detailed concrete moulds.

Features silicone casting rubber 

• Platinum cure (addition-cure): clean curing with minimal shrinkage.
• Shore A25: slightly flexible; firmer than Shore A15, yet still easy to demould.
• 1:1 mixing ratio: easy to measure and process.
• Low viscosity: flows easily into the mould and helps minimise air entrapment.
• High tensile and tear strength: for durable, long-lasting moulds.
• Food-safe silicone: certified for applications involving contact with food.
• Heat resistant: up to 200°C continuously and 300°C for short periods.
• Chemical resistance: resistant to epoxy resin hars, polyester casting resing, polyurethane casting resins, plaster, concrete and many other casting materials.
• Low shrinkage: minimal shrinkage after curing.

What is Shore A25 silicone rubber used for?

Shore A25 is the ideal choice when you need to produce sturdy, slightly flexible and highly detailed moulds for applications such as:

• Detailed concrete moulds. The higher Shore hardness provides the mould with sufficient rigidity to withstand the pressure of concrete, while still offering enough flexibility for easy demoulding without damaging the finished cast.
• Silicone moulds for epoxy resin castings.
• Moulds for polyurethane and polyester casting resins.
• Food-safe applications, such as moulds for chocolate, fondant and ice.

The slight flexibility of Shore A25 offers the ideal balance between rigidity and ease of demoulding, making it a versatile choice for both decorative and technical applications.

Processing platinum silicone casting rubber

1. Accurately weigh Component A (base, green) and Component B (curing agent, white) in a 1:1 ratio using a scale.
2. Mix both components thoroughly but gently for approximately 3 minutes using a mixing spatula. Scrape the sides and bottom of the mixing cup well. Then pour the mixture into a second, clean mixing cup and mix briefly again.
3. Pour the silicone slowly into the mould or mould box. The working time is approximately 45 minutes at 20°C. At higher temperatures, the silicone cures more quickly, giving air bubbles less time to escape.
4. After approximately 8 hours, the silicone is fully cured and tack-free.

Specifications

Type: Platinum-cure RTV-2
Hardness: Shore A25 (flexible)
Mixing ratio: 1:1
Colour: component A (green) / component B (white)
Specific gravity: 1.02 kg/dm³ (1 litre = approx. 1 kg)
Working time: approx. 45 minutes at 20°C
Curing time: approx. 8 hours (tack-free)
Heat resistance: 200°C continuously / 300°C for short periods
Food-safe: yes
Shelf life: 2 years (in unopened packaging)

Also available in other Shore hardnesses

Looking for a softer or firmer silicone rubber? RESION also offers the following 1:1 mix ratio variants:

• Shore A8 - very flexible
• Shore A15 - flexible
• Shore A40 - hard and rigid

Buy silicone casting rubber 1:1 Shore 25

Order Silicone Casting Rubber Shore A25 and all other silicone rubber products easily from Polyestershoppen.com. Place your order on working days before 5:00 PM CET, and it will be dispatched the same day. If you have any questions about silicone casting rubber or would like advice on choosing the right Shore hardness, feel free to contact one of our specialists.