To prevent rust on aluminum coil, ensure proper storage conditions by keeping the coils dry and avoiding contact with moisture. Use protective coatings or sealants that are compatible with aluminum to create a barrier against the elements. Regularly inspect the coils for signs of corrosion and clean them with a non-abrasive cleaner to remove any contaminants. Avoid using harsh chemicals that could accelerate oxidation. Maintain good ventilation in storage areas to reduce humidity, which can contribute to rust formation. Finally, consider using anodizing or other surface treatments that enhance the aluminum's natural resistance to corrosion.