Description / Abstract: Material Description. This specification covers the basic requirements for a conductive, hexavalent chromium free, one coat or two coat dip applied black corrosion protective coating system to be used over zinc-nickel (Zn-Ni) coated steel. The coating system consists of an optional zinc rich primer, approved non-chrome pretreatment, and one or two dip applied black pigmented topcoats. The optional zinc rich primer may be applied before painting on the outside of the tube to increase corrosion protection.

Symbols. Not applicable.

Applicability. 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. 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.

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.