Description / Abstract: This standard covers the minimum performance requirements for an exterior non-weatherable adhesion promoters and primers used on plastic substrates. This standard is to be used in conjunction with an appropriate 998xxxx painted product specification for primer technology approval. Primers covered by the standard may be either one component or multi-component materials.

Material Description. This primer is part of the total painted product system and must provide a smooth, adhesion-promoting coating direct to substrate or in-mold coating and to subsequent coatings.

Symbols. Qualified to this Material Specification. This primer is part of the total painted product system and must meet requirements set forth in the specifications for other materials with which it is, or will be, used. This specification shall be used in conjunction with the Approved Paint on Plastics System (APOPS), a section of the Materials Specification (MATSPC) file which lists approved substrate, cleaning, priming and topcoat combinations. APOPS test requirements are defined in GMW14797.

Applicability. Adhesion promoters and primers covered under this specification are typically applied as liquids. They are applied directly onto a plastic substrate or over an in-mold coating. They are used under an approved topcoat system. In some applications, a primer surfacer may be applied to the parts primer prior to topcoat applications. Primers tested to this specification are not approved for a wet-on-wet application with topcoat. The primer may or may not be conductive type for electrostatic spray application.