Premium Long-Potlife Kneadable Silicone for Professional Mold Making and Model Building Applications

Stensil ECO 50 L is a 2-component platinum-addition kneadable silicone (Shore A 50) that stands out for its long pot life of 10 minutes and cure time of 60 minutes at room temperature. The pink paste is easily mixed by hand in a 1:1 weight ratio. The extended processing time makes this variant ideal for larger molds, complex models, and applications where haste is counterproductive. With the same Shore A 50 hardness as the standard ECO 50, the L-variant offers identical physical properties but with more time to apply the paste precisely.

Key Benefits

• Pot life 10 minutes – six times longer processing time than standard Stensil ECO 50, for complex or large models without time pressure.
• Cure time 60 minutes – full cure within one hour at 20°C, fast enough for production work.
• Shore A 50 – medium hardness that combines flexibility for undercuts with firmness for repeated demolding.
• Shrinkage <0.1% – dimensionally accurate reproductions without distortion.
• Density 1.63 g/cm³ – stable paste for vertical and overhead applications.
• 1:1 mixing ratio by weight – easy manual mixing.

Typical Applications

• Large molds – molds where standard kneadable silicones offer insufficient processing time.
• Model making & prototyping – complex models with multiple undercuts requiring careful application.
• Restoration – historical ornaments and architectural details where accuracy takes precedence over speed.
• Jewelry & goldsmithing – large jewelry molds with filigree work.
• Education & workshops – longer processing time gives beginners more room for correction.
• Two-part molds – time to carefully build up the first half before the second half follows.

Processing instructions:

1. Take equal parts of A and B components by weight (1:1).
2. Knead both components thoroughly by hand until a uniform pink color is achieved.
3. Process the mixed paste within the 10-minute pot life.
4. Press the silicone over or around the model and wait 60 minutes at 20°C.
5. Demold once the silicone has fully cured and no longer feels sticky.
6. Full strength is reached after 24 hours.

Addition-cure silicone warning: Stensil ECO is a platinum-addition silicone that can be inhibited by sulfur, nitrogen, amine compounds, and metal salts. These substances are found in many latex gloves, some plasticines, varnishes, glues, condensation-cure silicones, 1-component silicone sealants, natural rubbers, and 3D printing materials (especially stereolithography/SLA). If in doubt, first test on a small area or apply a protective layer of polyvinyl alcohol.

Silconic GmbH & Co. KG is a German manufacturer of high-quality silicone elastomers with production in Lonsee. Since 2004, the company has been developing dental silicones under its own brands and is among the leading producers of RTV-2 silicones in Europe.

Professional Support

Are you unsure whether you need the standard ECO 50 or the Long-potlife variant? We are happy to advise you on the right choice based on your project size and complexity. Contact us via our website for personalized advice.