Which of the following materials is NOT considered a rust-preventing coating?

Heat shrink sleeves are typically used as protective coverings for pipes and cables but are not a rust-preventing coating in the traditional sense. Their primary function is to provide mechanical protection and moisture barriers rather than specifically to inhibit corrosion. In contrast, the other materials listed—liquid epoxy, FBE (fusion bonded epoxy), and oil-based paint—are formulated to provide corrosion resistance.

Liquid epoxy forms a tough, durable barrier that resists moisture and is often used in industrial applications to prevent corrosion. Fusion bonded epoxy is specifically designed for metal surfaces and provides excellent adhesion and protection against rust and corrosion. Oil-based paints can also function to prevent corrosion because they create a protective film on the surface, limiting exposure to moisture and oxygen, which are necessary for rust formation.

In summary, while heat shrink sleeves serve an important protective role, they do not actively prevent rust like the other options do.