Final answer:
MIL-C-81309 corrosion-preventive compound provides protection for about 30 days on exposed surfaces. The compound forms a protective coating to prevent corrosion.
Step-by-step explanation:
MIL-C-81309 corrosion-preventive compound is a water-displacing compound and lubricant that must be reapplied frequently. On exposed surfaces, protection lasts about 30 days at best. The compound forms a protective coating that hinders the access of oxygen and water to the underlying metal, preventing corrosion.