This specification covers the performance requirements to be used for a metalized finish that is protected within an exterior lighting application. The metalized finish is created using Physical Vapor Deposition (PVD); i.e., vacuum evaporation, sputter deposition, arc vapor deposition, etc. The coating system may consist of all or a select combination of the following: basecoat, metallic layer, protective topcoat and tinted top coat.

Material Description. Coating technology shall be documented with each approval.

Symbols. Not applicable.

Applicability. Typical applications are exterior lighting reflectors, bezels and decorative components which are protected by a lens within an assembly.

Remarks.

Coating approval per this specification is system specific; i.e., substrate, pretreatment, basecoat if required for Polyester Bulk Molding Compound (BMC) or metallic substrate, metallic layer and protective top coat or tinted top coat. The following describes system approval guidance for each type of coating.

• Metallic layer and in chamber protective topcoat Hexamethyldisiloxane, (HMDSO) have no material approval, application approved through the Approved Paint on Plastics Systems (APOPS) and/or Production Part Approval Process (PPAP) testing only.

• Tinted top coat approval is required for each colored tint on a single substrate and metallization process per GMW18024.

Substrate must be approved to the appropriate GM material specification.

APOPS Approvals shall be stored in the GM Materials Approved Source List (GMMASL), which lists approved substrate, cleaning, priming and topcoat combinations.

This standard may involve hazardous materials, operations and equipment. This standard does not propose to address all the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.