This specification covers the qualification and performance requirements for exterior, one component (1K) solventborne basecoat and two component (2K), matte finish i.e., low gloss solventborne clearcoat topcoats that perform over a bake latitude of 115 °C to 135 °C (240 °F to 275 °F).

Material Description.

Basecoat components of these systems are typically 1K (solvent) acrylic melamine. Clearcoat components of these systems are flexible 2K (solvent) urethane or urethane blends. Each combination of specific basecoat and clearcoat must be tested and approved as a basecoat/clearcoat (BC/CC) system. The individual components are not interchangeable and are approved for use only with combinations i.e., the basecoat/clearcoat used in qualification testing of the total paint system. This specification shall be used in conjunction with the Approved Paint on Plastics Systems (APOPS), found in the GM Materials Approved Source List, which lists approved substrate, cleaning, priming, and topcoat combinations. APOPS test requirements are defined in GMW14797.

Symbols.

Not applicable.

Applicability.

Topcoats designed for application over a baked primer or adhesion promoter. All Thermoplastic Polyolefin (TPO) substrates using 9984864 must be over an adhesion promoter (9984808 or 9984810) or flame treatment per GMW16133.

Remarks.

None.