This specification covers the performance and qualification requirements for exterior, one-component (1K) solventborne basecoat and two-component (2K), matte finish (low gloss), solventborne clearcoat topcoats that perform over bake latitude of 82 °C to 135 °C (180 °F to 275 °F).

Material Description.

Basecoat components of these systems are typically 1K (solvent) acrylic melamine. Clearcoat components of these systems are 2K (solvent) urethane or urethane blends. Each combination of specific basecoat and clearcoat must be tested and approved as a basecoat/clearcoat system. The individual components are not interchangeable and are approved for use only with combinations of basecoat/clearcoat of the total paint system that were used in qualification testing.

Qualified to this Material Specification.

Each combination of specific basecoat and clearcoat must be tested and approved as a basecoat/clearcoat topcoat system. The individual components are not interchangeable. This specification shall be used in conjunction with the GMW14797: Approved Paint on Plastic System (APOPS), a section of the GM Materials Approval Source List, which lists the approved substrate, cleaning, priming, and topcoat combinations. In addition, the topcoat system is part of the total coating system and must meet qualifications set forth in this specification and those shown on engineering drawings for appearance and durability.

Symbols.

Not applicable.

Applicability.

These topcoats can be used on heat sensitive plastics, flexible or rigid plastic parts and are designed to be applied over a baked primer or adhesion promoter.

Note: All Thermoplastic Polyolefin (TPO) substrates using 9986266 must be primed with a 9984905, 9984908 adhesion promoter or flame treatment per GMW16133.

Remarks.

Not applicable.