Yes, aluminum trim coil has good corrosion resistance. Aluminum naturally forms a thin oxide layer on its surface, which acts as a protective barrier against corrosion. This oxide layer helps to prevent the underlying aluminum from being affected by moisture, air, and other corrosive elements.

Aluminum trim coil is typically coated or painted to enhance its durability and resistance to corrosion. These coatings provide an additional layer of protection and can further enhance the performance of the trim coil in harsh environments. Common coatings used on aluminum trim coil include polyester, polyvinylidene fluoride (PVDF), and acrylic coatings.

The choice of coating can depend on the specific application and the level of corrosion resistance required. PVDF coatings, for example, are known for their exceptional resistance to fading, weathering, and chemical exposure, making them suitable for trim coil used in coastal or highly corrosive environments.

However, it's important to note that the longevity of the corrosion resistance can also depend on factors such as the quality of the coating, the installation method, and the maintenance practices. Regular cleaning and proper care can help to prolong the corrosion resistance of aluminum trim coil and maintain its appearance over time.