GMNA GMN4991 PDF

1 Scope

This specification covers the basic requirements for a hexavalentchromefree onecoat dip applied black corrosion protective coating system to be used over ZnNi coated steel. The coating system consists of an approved non chrome pretreatment and a dip applied black pigmented topcoat.

1.1 Typical Application. This coating system is typically used on fuel filler pipes fabricated of ZnNi coated sheet steel. The coating is suitable for the interior and exterior of fuel filler pipe assemblies where high level of corrosion protection, a black color, and freedom from hexavalent chromium are required.

1.2 Remarks. The coating system must be resistant to conventional hydrocarbon fuels and ethanolbased flex fuels ranging from E0 to E85.