scope:

Material Description.

Powder coatings for the purpose of this specification shall be defined as organic resin material in a finely powdered state, for application to suitably prepared ferrous or nonferrous metallic surfaces, followed by heat cure (to develop the desired characteristics in the finished film). Generally, a specific material requirement and color will be shown on the engineering drawing, otherwise any powder coating may be used, provided that the test requirements of the specifications are met.

These coatings are intended to insure adequate protection against corrosion on surfaces of both external and internal parts of passenger and commercial vehicles.

In order to meet the requirements of this specification it is necessary for components to undergo a suitable cleaning process/removal operation (including scale or other oxide layers). Cleaning is to be followed by an appropriate pretreatment before powder coat application.

The pretreatment (e.g., low zinc, 3-cations-phophating) shall ensure good adhesion. Iron phosphate is prohibited by GME for type C. It is not preferred but is permitted by GMNA. Primer may be used if specified on the engineering drawing.

These coatings may be applied by electrostatic spray or fluidized bed techniques.