Wacker Catalyst Paste T 40 – Curing Agent/Catalyst for ELASTOSIL® M Condensation Silicones & Mould Making

Premium Tin-Cure Catalyst for Professional Mould Making and Reproduction Applications

Wacker® Catalyst Paste T 40 is a red, ready-to-use curing agent in paste form for condensation-cure (tin-cure) RTV-2 silicones from the Wacker ELASTOSIL® M series. The paste ensures fast, reliable curing at room temperature, with a density of 1.1 g/cm³ and a flash point of 55 °C (ISO 2719). The standard dosage ratio is 2 to 3 percent by weight on the silicone Part A, whereby more curing agent leads to faster curing and a shorter pot life, and less curing agent to a longer demoulding time and a better chance for air bubbles to escape. The red colour serves as a visual check for homogeneous mixing with the white or grey silicone base. T 40 is ideally suited for applications where fast curing, reliable reactivity and easy manual processing are essential.

Key Benefits

• Paste consistency for exact dosing: – the viscous paste prevents spills and makes accurate dosing by weight easy, even for small batches
• Dosage ratio 2–3 wt.%: – flexible adjustment of curing time and pot life to the working conditions without compromising final quality
• Red signal colour: – visual control during mixing ensures that the catalyst is completely and homogeneously distributed through the silicone for consistent curing
• Density 1.1 g/cm³: – stable and predictable dosing weights with every M series system
• Flash point 55 °C (ISO 2719): – safe to handle under normal workshop conditions, provided ignition sources are avoided
• Broad compatibility within the M series: – suitable for both pourable (M 4400, M 4440, M 4470) and kneadable (M 1470) condensation silicones from Wacker

Typical Applications

• Curing Wacker ELASTOSIL® M 4400, M 4440 and M 4470 for casting moulds in mould making and reproduction
• Curing Wacker ELASTOSIL® M 1470 kneadable condensation silicone for hand-modelled moulds
• Production of moulds for polyurethane, polyester, epoxy and plaster
• Heat-resistant moulds for low-melting metals such as tin, lead and zamak (in combination with M 4470)
• Restoration and reproduction work in sculpture, decorative plaster and historic buildings
• Prototyping moulds where a short demoulding time and easy manual processing are desirable

Processing instructions:

1. Briefly stir the silicone Part A before use to remedy any settling of fillers.
2. Weigh out 2 to 3 parts by weight of T 40 paste per 100 parts by weight of silicone Part A; more paste accelerates curing and shortens the pot life.
3. Mix both components thoroughly by hand or slowly by machine until a uniform, streak-free colour is achieved.
4. Optionally degas under vacuum for critical applications to remove air inclusions.
5. Pour or apply the mixture within the pot life stated in the TDS of the ELASTOSIL® M silicone used.
6. Allow the mould to cure completely at room temperature according to the curing time of the silicone used before demoulding.

Please note: Pot life, demoulding time and final properties are also determined by dosage, ambient temperature and humidity. Higher temperature or humidity accelerates curing and shortens the pot life. Never mix larger quantities than you can process within the pot life. Store the tube dry, cool, frost-free and tightly closed; under these conditions the shelf life is at least one year.

Manufactured by Wacker Chemie AG, world market leader in the development and production of silicones for industrial and technical applications.

Professional Support

Our technical specialists advise on the correct dosage ratio for your silicone, the influence of temperature and humidity on pot life, and the optimal combination of T series curing agents for your specific mould-making application. Contact us for technical data sheets, processing guides or product advice.