Momentive RTV108 Translucent High Performance Adhesive is a one-component, ready-to-use extremely versatile adhesive sealant. RTV108 cures at room temperature to a tough, durable, resilient silicone rubber. The paste consistency is perfect for application on vertical and overhead surfaces where pourable/self-leveling sealants are not practical. Due to the moisture cure system, do not use in a thicknesses of greater than 6mm (1/4 in.).
Key Features and Benefits
- One-component products
- Capability to cure at room temperature and ambient humidity
- Self adhesion properties
- Low temperature flexibility
- High temperature performance
- Excellent weatherability and ozone and chemical resistance
- Excellent electrical insulation properties
Potential Applications: General purpose bonding, sealing, electrical insulation, formed-in-place gaskets. Apply to vertical or overhead surfaces.
These sealants are not for use in delicate electrical and electronic applications in which corrosion of copper, brass or other sensitive metals is undesirable.
Surface Preparation: RTV108 Translucent Adhesive will bond to many clean surfaces without the aid of primers. These surfaces typically include many metals, glass, ceramic, silicone rubber and some rigid plastics. RTV108 will produce a fair bond to organic rubber and to some flexible plastics. Difficult to bond substrates may require the use of primers SS4004, SS4044 or SS4179. Complete information for these primers is available in a separate product data sheet and available upon request.
Thoroughly clean the surface with a suitable solvent to ensure proper adhesion. Wipe the surface dry before applying and use proper safety precautions when using solvents.
Application and Cure Time Cycle: RTV108 may be applied directly to clean or primed substrates. To mate broad surfaces, apply sealant in a thin bead or ribbon around the edge of the surfaces to be bonded.
The cure process begins with the formation of a skin on the exposed surface of the sealant and progresses inward through the material. This surface skin will be tack-free to the touch in 15 to 30 minutes. Once the tack-free skin has begun to form, further tooling of the adhesive sealant is not advisable. A by-product of the cure process releases acetic acid vapors from the sealant surface. Once fully cured, this odor will disappear. A 3mm (1/8 in.) section of adhesive sealant will cure through in approximately 24 hours at 25°C (77°F) and 50% R.H. Since cure time increases with thickness, limit section thicknesses of 6mm (1/4 in.) or less. Higher temperatures and humidity will accelerate the cure process, low temperatures and low humidity will slow the cure rate.
Bond Strength Development: In addition to the effects of temperature and relative humidity, development of maximum bond strength will depend on joint configuration, degree of confinement, sealant thickness and substrate porosity. Normally, sufficient bond strength will develop in 12 to 24 hours to permit handling of parts. Minimum stress should be applied to the bonded joint until full adhesive strength is developed. Eventually the adhesive strength of the bond will exceed the cohesive strength of the silicone rubber sealant itself. Always allow maximum cure time available for best results.
Packaging: RTV adhesive sealants from Momentive Performance Materials are available in ready-to-use collapsible aluminum squeeze tubes, caulking cartridges and in bulk containers.
Clean Up and Removal: Before curing, solvent systems such as naphtha or methyl ethyl ketone (MEK) are most effective. Refer to solvent use warnings in the section on surface preparation. After cure, selected chemical strippers which will remove the silicone rubber are available from other manufacturers.
Limitations: Customers must evaluate Momentive Performance Materials products and make their own determination as to fitness of use in their particular applications.
Safety Precautions: Comply with all local safety, disposal and transportation regulations. Check the Safety Data Sheet (SDS) and label of the individual products carefully before using the products. SDS’s are available on request.