Chemlok 219 Urethane-to-Metal Primer and Adhesive

Product overview

Chemlok 219 bonds polyether and polyester castable polyurethanes to metal. It can be used as a one-coat adhesive or as the primer beneath Chemlok 213 where increased environmental resistance is required.

Materials and system selection

• Suitable for castable polyurethane systems based on TDI or MDI, across a range of hardnesses.
• Also suitable for millable urethane and selected thermoplastic polyurethane (TPU) applications.
• In the two-coat system, Chemlok 219 provides the metal primer layer and Chemlok 213 is the covercoat.

Application guidance

Remove oils, grease, rust and oxide layers from the metal using suitable chemical or mechanical preparation. Apply Chemlok 219 by brush, spray or dip as a uniformly thin film. The dry-film thickness should be 12.7 μm. Excessive film build from repeated brushing or poor drainage can reduce performance. Allow 30–45 minutes of air drying at room temperature.

Chemlok 219 is heat-reactive: avoid excessive prebake time or temperature. If prebaking extends beyond 1 hour at 100°C, use Chemlok 219 as a primer beneath Chemlok 213. For this two-coat system, dry each layer before proceeding; a prebake of at least 2 hours at 121°C is recommended for optimum performance. Large parts may require longer heating, depending on size.

Typical properties

Property	Typical value
Appearance	Clear to amber liquid
Viscosity at 25°C	50–110 cps, Brookfield LVT, spindle 2, 30 rpm
Density	880–910 kg/m³
Solids by weight	23.5–27.0%
Solvent system	Ethanol, methyl isobutyl ketone (MIBK)

Typical values are for reference, not product specifications. Confirm the polyurethane formulation and heating cycle for the intended application.

Supply and technical enquiries

Hongtu Chemical supplies Chemlok 219 as an authorized distributor. Contact our team for quotations, technical documents or advice on polyurethane bonding.