Chemlok 218GB Polyurethane Bonding Adhesive

Chemlok 218GB is a solvent-based adhesive for castable and millable polyurethane elastomers bonded to metals and other rigid substrates. It can be used as a one-coat system without a primer.

For castable polyurethane, Chemlok 219 can be used beneath Chemlok 218GB to increase resistance to environmental exposure. In this arrangement, Chemlok 219 protects the metal as the primer, while Chemlok 218GB provides the bond to the polyurethane.

Apply and air-dry the primer before applying Chemlok 218GB. Air-dry the covercoat before prebaking the combined coating at 121°C for the selected process time.

Clean the substrate to remove oil, grease, rust and oxide layers. Chemlok 218GB does not require agitation before or during use. Apply by brush, dip, spray or roll coat to a dry-film thickness of 19–32 μm.

Allow at least 60 minutes of air drying at room temperature for complete solvent evaporation. To enhance cohesive strength, bake coated inserts for at least 2 hours at 121°C; large inserts require longer heating because of their greater thermal mass. The molding and cure cycle must suit the polyurethane compound being processed.

Property	Typical value
Appearance	Clear to slightly hazy amber liquid
Viscosity at 25°C	500–1200 cps, Brookfield LVT, spindle 3, 60 rpm
Density	960–1020 kg/m³
Solids by weight	18.0–21.0%

Typical values are for reference, not product specifications.

Hongtu Chemical supplies Chemlok 218GB as an authorized distributor. Contact our team to discuss the materials, process and technical documents for your application.