There are two primary methods for attaching silicone: using a specialized silicone adhesive or employing a cyanoacrylate (instant adhesive) with a primer.
Methods for Attaching Silicone
1. Using Silicone Adhesive
This is the most common and often the most reliable method. Silicone adhesives are specifically formulated to bond with silicone rubber and other materials.
- Types of Silicone Adhesives: Choose a silicone adhesive appropriate for your specific application (e.g., general purpose, high-temperature, food-grade).
- Surface Preparation: Ensure the silicone surfaces are clean, dry, and free of any contaminants like oil or dust. Isopropyl alcohol can be used for cleaning.
- Application: Apply the silicone adhesive evenly to one or both surfaces being joined.
- Curing: Allow the adhesive to cure completely according to the manufacturer's instructions. Clamping or applying pressure during curing may improve the bond strength.
2. Using Cyanoacrylate (Instant Adhesive) with a Primer
While silicone is generally difficult to bond, using a cyanoacrylate (instant adhesive) can be effective if combined with a suitable primer. This method is faster than using silicone adhesive, but it requires careful preparation.
- Primer Application: Apply a silicone primer (such as Permabond POP) to the silicone surfaces you wish to bond. The primer modifies the surface, making it receptive to the adhesive. Allow the primer to dry completely according to the manufacturer's directions.
- Adhesive Application: Choose a flexible cyanoacrylate adhesive (such as Permabond 2050) as these offer better long-term durability and resistance to movement compared to more rigid formulations. Apply the adhesive to one of the primed surfaces.
- Bonding: Immediately join the two surfaces together and apply pressure for the time specified by the adhesive manufacturer.
- Curing: The adhesive will cure rapidly.
Key Considerations
- Surface Cleanliness: Cleanliness is crucial for both methods. Contaminants can significantly weaken the bond.
- Adhesive Compatibility: Ensure the selected adhesive is compatible with the specific type of silicone you are using. Different silicone formulations may require different adhesives.
- Application Environment: Consider the environmental conditions the bond will be exposed to (e.g., temperature, humidity, chemicals). Choose an adhesive rated for those conditions.
- Testing: Always test the bond strength on a small, inconspicuous area before applying the adhesive to the entire project.
