Full definition
The process of permanently bonding pre-vulcanized (cured) rubber to metal substrates using a multi-step adhesive system, typically required for field repairs, retrofits, and applications where co-vulcanization (bonding during molding) is not possible. Process: (1) Metal preparation — thorough degreasing (solvent wipe or vapor degrease), followed by grit blasting to SA 2.5 / NACE 2 profile using 16-30 mesh alumina or steel grit (this step is critical — bond strength correlates directly with surface profile quality). (2) Primer application — within 4 hours of blasting to prevent re-oxidation; the primer chemically bonds to the metal oxide layer. (3) Adhesive (cover coat) application — the adhesive bonds to the primer and to the rubber surface, which must be freshly buffed to expose reactive rubber. (4) Assembly — press rubber to metal with firm, uniform pressure. (5) Cure — room temperature (24-72h) or elevated temperature (accelerated). Bond strength should exceed rubber tear strength (failure in rubber, not at bond line). Leading adhesive systems: LORD Corporation (Chemlok/Chemosil — the industry standard, two-coat system), Henkel (Loctite/Bonderite), and Rema Tip Top. Per ASTM D429 for bond strength testing. Applications: rubber lining of pipes and vessels, repair of anti-vibration mounts, roller re-covering, and conveyor drum lagging.