Rust preventative coatings are designed to minimize rust or iron alloy corrosion when applied directly to ferrous metal such as carbon or alloy steels. They protect against rust by preventing moisture from reaching the metal or under lying substrate or by providing a sacrificial layer. Resin-based coatings are corrosion and chemically resistant and provide a barrier to protect the substrate. Zinc or aluminum rust preventative coatings provide a sacrificial layer that galvanicly protects the ferrous surface, even if the layer is breached in places. Zinc phosphate, barium metaborate and strontium chromate (all pigments) are common ingredients in corrosion-inhibitive coatings. These pigments absorb any moisture that enters the coating film. Lubricant, oil and grease coating provide a water repellent barrier, which inhibits corrosion.