Samsil Semi Clear 25 – RTV-2 Silicone Rubber, Shore(A) 23-27

Samsil Semi Clear 25 is a 2-component polyaddition silicone that cures at room temperature. This is a very robust and simple 1:1 system based on a platinum catalyst. This silicone combines high tear resistance with relatively good transparency — not crystal clear, but significantly more transparent than most standard silicones.

Specific properties

• Low viscosity, good ventilation
• High tear and tensile strength
• Non-bleeding
• Higher transparency than most silicones

Compatible additives

• Thixo – to thicken the consistency
• Inhibitor – to extend pot life and cure time
• Accelerator – to shorten pot life and cure time
• Pigment – for color addition

Technical Characteristics

Basic Specifications:

• Type: 2-component platinum-cure silicone (poly-addition)
• Mixing ratio: A:B = 100:100 (1:1 by weight)
• Pot life: 30 minutes at 25°C
• Cure time: 3-5 hours at 25°C
• Full strength: 1 day at 25°C
• Appearance: Colorless transparent
• Density: 1.03 g/cm³ at 25°C
• Viscosity: 12,000 ± 500 mPa·s at 25°C
• Hardness (DIN 53505): Shore A 23-27
• Tear strength: 5 kg/cm
• Tensile strength: 12 kg/cm²
• Elongation at break: 500%
• Shrinkage: <0.1%

Processing Instructions:

1. Carefully mix component A and B in a 100:100 ratio (1:1 by weight) by hand or machine
2. Stir slowly in a figure-8 motion to prevent air entrapment
3. Process the mixture within the 30-minute pot life
4. Wait until fully cured before demolding (3-5 hours at 25°C)
5. Curing can be accelerated by heating – every 10°C temperature increase roughly halves the time

Storage & Use

• Store in a dry place between 5 and 25°C, in a tightly closed container, protected from direct sunlight. Shelf life at least 1 year if stored properly.
• Addition-curing silicones can be contaminated by materials such as sulfur and tin salts. Avoid contact with these substances. Consult our website for a comprehensive list of potential inhibitors.
• Working and curing time are highly dependent on temperature. Higher temperatures shorten working times.

Important Warning: Inhibition in Addition Silicones

Please note: This is an addition-cure silicone (platinum-cure). These silicones can be poisoned by sulfur, nitrogen, amino compounds, and metal salts. If you are unsure whether the products you are using (including gloves, spatulas, and cups) contain these ingredients, please perform a small test first.

Note: Do not deviate from the mixing ratio (1:1), as this will change the properties of the silicone.

The stated results are standard indications and not specifications. The customer must test the product to determine if it is suitable for the intended purpose.