Chemlok 238(NW)GB Rubber Bonding Covercoat

Chemlok 238(NW)GB is a solvent-based covercoat for bonding non-polar elastomers to one another or to metal and other rigid substrates primed with Chemlok 205GB. Butyl rubber and EPDM are key applications.

The adhesive can join uncured rubber to cured rubber, as well as cured elastomers with similar compositions. Its elastomer range also includes natural rubber, polyisoprene, SBR, BR, CR and NBR; the rubber formulation and bonding arrangement determine the appropriate process.

For primed metal, allow Chemlok 205GB to dry thoroughly before applying the covercoat.

Clean and prepare the substrate before coating. Mix Chemlok 238(NW)GB to a uniform consistency and maintain adequate agitation during use. It can be applied by brush, dip, roll coat or spray, avoiding runs and uneven film build.

The general dry-film thickness is 10.2–25.4 μm; some rubber compounds may require a thicker film. For cured-rubber bonding, 25.4–38.1 μm is normally used. Allow the coating to dry until the solvent has fully evaporated, approximately 30–60 minutes at room temperature.

Property	Typical value
Appearance	Black liquid
Viscosity at 25°C	100–800 cps, Brookfield LVT, spindle 2, 30 rpm
Density	890–960 kg/m³
Solids by weight	12.0–15.0%

Typical values are for reference, not product specifications.

Hongtu Chemical supplies Chemlok 238(NW)GB as an authorized distributor. Contact our team to discuss the materials, process and technical documents for your application.