This specification covers the qualifications and performance requirements for flexible, exterior, one component (1K), solventborne basecoat/1K solventborne clearcoat topcoats for use over plastic substrates, typically thermoplastic olefin, over a bake latitude of approximately 115 °C to 135 °C (240 °F to 275 °F). This topcoat system is not intended for use on large exterior surfaces such as fascia, spoilers, and rocker panels on vehicles produced for the North American market.

Material Description. Basecoat (BC) components of these systems are typically 1K (solvent) acrylic/melamine. Clearcoat (CC) components of these systems are 1K (solvent) technologies with varying cross-linking chemistries, but typically acrylic/melamine. Typical volume solids as sprayed are typically 35% to 50% for BCs and 45% to 60% for CCs. Each combination of specific BC and CC must be tested and approved as a BC/CC system. The individual components are not interchangeable and are approved for use only with combinations of BC/CC of the total paint system which was used in the qualification testing. It must also be compatible with specific adhesion promoters and/or primers used with specific plastics. This specification shall be used in conjunction with the GMW14797, Approved Paint on Plastics Systems (APOPS), a section of GM Materials Approved Source List which lists approved substrate, cleaning, priming, and topcoat combinations.

Symbols. Not applicable.

Applicability. These topcoats are designed to be applied over an approved adhesion promoter or baked primer. All thermoplastic polyolefin substrates using 9984852 must be applied over an adhesion promoter (9984808 or 9984810) or flame treatment per GMW16133.

Remarks. None.