scope:

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

Note: Nothing in this standard supercedes applicable laws and regulations.

Note: In the event of conflict between the English and domestic language, the English language shall take precedence.

Purpose/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 BC and CC shall be tested and approved as a BC/CC system. The individual components are not interchangeable and are approved for use only with combinations i.e., the BC/CC 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 (GMMASL), 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 GMW18632 shall be over an adhesion promoter (GMW18414 or GMW18415) or flame treatment per GMW16133.

Remarks.

None.