GREENSIL® Slow – Long Working Time Platinum Cure Silicone for Larger Moulds
GREENSIL® Slow is a 20A platinum cure silicone rubber for mould making, formulated for Australian makers who need extra time for larger pours, vacuum degassing, short production runs, and detailed work, at a more economical price than premium fast-set systems. Also referred to as an addition cured silicone or RTV silicone (room temperature vulcanizing), it cures via a platinum-catalyzed addition reaction with no by-products and minimal shrinkage.
Why Use GREENSIL® Slow?
Not every mould requires ultra-fast de-mould times or premium high-production performance. GREENSIL® Slow fills the gap for makers and studios who want a slower platinum silicone that is easier to manage for larger pours, detailed moulds and projects where additional working time is beneficial. Compared to fast-set silicones, GREENSIL® Slow gives users more control during mixing and pouring, particularly when vacuum degassing, pouring larger mould volumes or working on complex pieces. It also offers a more economical option for short-run moulds, prototyping and non-critical production tooling.
Let’s Get Technical
- Recommended For: Larger silicone pours, short-run moulds, test moulds, prototypes, non-critical tooling, projects where cost control and working time are key.
- Mix Ratio: 1A:1B by volume
- Hardness & Type: 20A +/-2 and Silicone Rubber
- Pot Life & De-mould: Work time 20-30 mins / De-mould time 3-4 hours at 23°C
- Cure Type: Platinum Cure (Addition Cure)
- Viscosity: 7,500 cps
- Colour: Green
Key Features
- Longer working time for controlled pours and detailed moulds
- Simple 1:1 mix ratio for easy measuring and mixing
- Suitable for vacuum degassing applications
- Economical platinum silicone option
- Flexible cured rubber with good tear resistance
- Excellent surface detail reproduction
- Low shrinkage during cure
- Suitable for resin, plaster and wax casting applications
Applications
- Silicone mould making
- Resin casting moulds
- Plaster and gypsum moulds
- Wax casting moulds
- Concrete moulds for short-run casting
- Special effects and prop making
- Prototype and concept moulds
- Production backup moulds
- Large silicone pours
- Detailed moulds requiring vacuum degassing
Who Is GREENSIL® Slow For?
GREENSIL® Slow is suitable for both beginners and experienced mould makers looking for additional working time and a more economical platinum silicone system.
It is particularly well suited to workshops, prop makers, SFX studios, production environments, artists, prototypers and makers producing short-run moulds or larger moulds where a slower cure is an advantage.
Frequently Asked Questions
What is the difference between GREENSIL® Slow and Pinkysil®?
GREENSIL® Slow has a longer working time and slower cure, making it better suited to larger pours, degassing and economical mould making. Pinkysil® is a premium fast-set silicone designed for rapid turnaround and higher production efficiency.
Can GREENSIL® Slow be used for resin casting?
Yes. GREENSIL® Slow is suitable for moulds used with many polyurethane resins, epoxy resins, plaster, wax and other common casting materials.
Can I vacuum degas GREENSIL® Slow?
Yes. The extended working time makes GREENSIL® Slow suitable for vacuum degassing prior to pouring.
Is GREENSIL® Slow food safe?
Once fully cured, GREENSIL® Slow is formulated to comply with the relevant requirements of FDA 21 CFR 177.2600. Users should conduct their own suitability testing for the intended application.
Can beginners use GREENSIL® Slow?
Yes. The slower curing profile and 1:1 mix ratio make it a beginner-friendly platinum silicone system with more working time than fast-set alternatives.
How long does GREENSIL® Slow take to cure?
At 23°C, GREENSIL® Slow has a working time of approximately 20-30 minutes and typically cures in 3-4 hours. Cure times may vary depending on ambient temperature, humidity, and the mass of material being mixed. Lower temperatures will slow the cure, while warmer conditions may accelerate it.
What is the shelf life of GREENSIL® Slow?
GREENSIL® Slow has a shelf life of up to 12 months from the date of manufacture when stored unopened in its original containers at temperatures between 15°C and 25°C. Keep containers tightly sealed and avoid contamination during use to maximise product performance.
Can I use a mould release with GREENSIL® Slow?
Yes. Although GREENSIL® Slow exhibits excellent release properties against many materials, a suitable mould release may be beneficial when casting certain resins, extending mould life, or when moulding porous substrates such as timber, plaster, concrete, or some 3D prints. Always test your chosen release agent to ensure compatibility with both the silicone and casting material.
