CAF 1 silicone elastomer
High-temperature resistant 1K silicone adhesive (red)
CAF 1 — 1K silicone sealant, red, ready to use.
Temperature-resistant up to +225 °C continuously / +300 °C peak. Shore A 47, skin formation 7 min. For motors, heating elements, and aviation. From our Swiss warehouse.
documents
Internal reference:
40-301.TU
HS code:
39100000
CAF 1 Silicone Elastomer – the high-temperature sealant for engines, electrical engineering, and aviation
CAF 1 from Elkem is a one-component silicone elastomer that cures at room temperature when exposed to atmospheric moisture. This red, viscous paste was specifically developed for industrial sealing and bonding applications that require both long-term temperature resistance and immediate workability without the need for a two-component mixture. With a Shore A hardness of 47, a temperature resistance of −65°C to +225°C in continuous use, and a short-term peak tolerance of up to +300°C, CAF 1 has been a standard sealing compound for decades in engine manufacturing, electrical engineering, and aircraft maintenance.
Acetate-curing (acid-curing) silicones are characterized by their rapid reaction with atmospheric moisture: at 23°C and 50% relative humidity, a stable skin forms in as little as seven minutes. A two-millimeter-thick layer is fully cross-linked after six hours, and after 24 hours, CAF 1 cures completely up to a layer thickness of 4.3 mm. This curing profile makes the product particularly suitable for applications where seals are to be put into service on the same day.
What is CAF 1 typically used for?
The largest application segment is engine sealing in the automotive aftermarket. In the cylinder head area, on valve covers, and for bearing seals, the material must not only possess mechanical elasticity but, above all, resistance to hot oil, glycol, and short-term peak temperatures—exactly the performance profile that CAF 1 consistently delivers. The sealant is also well-established in electrical engineering and for electric heating elements, as its dielectric properties (dielectric strength 20 kV/mm, volume resistivity 1×10ⁿ⁵ Ω·cm) qualify it as an insulating material. In aircraft maintenance and repair, CAF 1 is frequently used to seal housings, fluid lines, and onboard systems. Additional applications include the repair of enamel and ceramic surfaces, as well as general machinery maintenance, where a flexible, heat-resistant, and chemically resistant sealant is required.
How should CAF 1 be used correctly?
CAF 1 is supplied ready-to-use and can be applied either manually from a tube or robotically in automated dispensing systems. A clean, dry, and grease-free bonding surface is essential for proper adhesion. Depending on the substrate, the system may require a primer: CAF 1 adheres to glass, enamel, and ceramics without a primer, but on metals, Primer 131 is recommended; on polar plastics, the Elkem primers PM 820 or PM 824. The sealant is applied to one side; the parts to be joined must then be joined and aligned within the skin formation time of approximately seven minutes. Full strength is achieved after seven days. A slight acetic acid odor is emitted during curing—ensure adequate ventilation when working in enclosed spaces.
What is the coverage limit?
CAF 1 exhibits high adhesion to typical industrial materials. In a standardized adhesion test on AG3 aluminum, the product achieves a tensile shear strength of 1.8 MPa with a joint thickness of one millimeter and seven days of curing. Failure is 100% cohesive—that is, the silicone itself tears before the bond to the metal fails. This property is an important quality indicator: if the failure were adhesive (i.e., at the interface), one would expect an unreliable bond. Thus, the bond is effectively as strong as the vulcanized silicone itself.
Storage and Containers
When stored in its unopened original packaging at temperatures between 2°C and 30°C, CAF 1 can be stored for up to 24 months from the date of manufacture. Once opened, the package should be used up quickly, as contact with atmospheric moisture triggers cross-linking. CAF 1 is supplied in 100-g tubes, in cans, and in industrial containers of 25 kg and 230 kg. For applications requiring higher flowability, the CAF 1 Extra Fluid variant is available with a Brookfield viscosity of 7,500 mPa·s (compared to 250,000 mPa·s for CAF 1).
CAF 1 is supplied by SILITECH AG with technical support, a batch certificate, and shipping from our Swiss warehouse within 24 hours.
Frequently Asked Questions About CAF 1
Answers to the most frequently asked questions about the application, properties, and processing of CAF 1 silicone elastomer.
CAF 1 is a single-component, high-temperature silicone sealant designed for industrial sealing and bonding applications. Its primary applications include engine sealing in the automotive aftermarket, sealing electrical heating elements, and maintenance and repair in the aviation industry. Thanks to its primer-free adhesion to glass, enamel, and ceramics, the product is ready for immediate use.
CAF 1 is resistant to continuous use from −65°C to +225°C (measured on a 2 mm layer over 1,000 hours). For short periods (up to 72 hours), the sealant can withstand temperatures up to +300°C. This makes CAF 1 suitable for engine seals, heating elements, and other high-temperature applications where other silicones fail.
CAF 1 forms a skin after just seven minutes at 23°C and 50% relative humidity. Components must therefore be joined quickly. Full cure is achieved after 24 hours at a layer thickness of 4.3 mm; a 2 mm thick layer is fully cross-linked after 6 hours. Final strength is achieved after 7 days.
Cured CAF 1 achieves a Shore A hardness of 47, with a tensile strength of 4.4 MPa, an elongation at break of 200%, and a tear resistance of 6 kN/m. The tensile shear strength on AG3 aluminum is 1.8 MPa with 100% cohesive failure—i.e., the material tears before the bond fails.
product specifications
| Physical properties | |
|---|---|
| Paint cured | red |
| Self-leveling | No |
| consistency | Pasty |
| product information | |
|---|---|
| brand | CAF |
| network type | Single-component (relative humidity) |
| manufacturer | Elkem Silicones |
| Number of components | 1K (single-component) |
| mixing ratio | Single-component |
| container | 100 g |
| Additional features | |
|---|---|
| UV resistance | No |
| product approvals | |
|---|---|
| food contact | No |
| Suitable for medical use | No |
| Areas of application | |
|---|---|
| Main application | Electronic potting or Sealing & Joints or Protective Coating (Conformal) or Bonding |
| Electrical Properties | |
|---|---|
| Electrical insulation | Yes |
| keywords | |
|---|---|
| keywords | |
| Mechanical properties | |
|---|---|
| Shore A hardness | 47.0 Shore A |
| Modulus at 100% elongation | 2.0 MPa |
| tensile strength | 4.4 MPa |
| elongation at break | 200.0 % |
| Tear resistance | 6.0 kN/m |
| processing | |
|---|---|
| Viscosity of the mixture | 250,000 mPa·s |
| Flowability | 5.0 min |
| skin formation time | 7.0 min |
| Fully cured after 24 hours | 4.3 mm |
| Mesh 2 mm layer | 6.0 h |
| Physical & Thermal | |
|---|---|
| Density (23°C) | 1.15 g/cm³ |
| Temperature resistance (duration) | -65 to 225 °C |
| Peak temperature (short-term) | 300 °C |
| thermal conductivity | 0.3 W/(m·K) |
| Electrical specifications | |
|---|---|
| Dielectric constant ε (1 kHz) | 3.0 |
| Dielectric strength | 20.0 kV/mm |
| Forward resistance | 1e+15 Ω·cm |
| Loss factor tan δ | 0.003 |
| storage | |
|---|---|
| Shelf life in original packaging | 24 months |
| Storage temperature | 2 to 30 °C |