Material Description.

This specification covers the basic requirements for a conductive hexavalent-chrome-free one-coat dip applied black corrosion protective coating system to be used over Zn-Ni (zinc-nickel) coated steel. After validation, it may also be used over other substrates such as Zn-Fe (galvannealed) or pure zinc (hot dip) coated steel. The coating system consists of an approved non-chrome pretreatment and a dip applied black pigmented topcoat. This coating typically contains epoxy, so it is not recommended for use in locations where it will be exposed to sunlight. In the instances where a fuel filler pipe will be exposed to direct sunlight, a separate topcoat should be developed and then specified on the drawing.

Symbols.

Not applicable.

Typical Applications.

This coating system is typically used on fuel filler pipes fabricated of Zn-Ni coated sheet steel. The coating is suitable for the interior and exterior of fuel filler pipe assemblies where high level of corrosion protection and a black color are required.

Remarks.

The coating system must be resistant to conventional hydrocarbon fuels, ethanol-based flex fuels ranging from E0 to E100, and B5 and B20 bio-diesel.