Manufacturers using prepainted metal for its attractive and durable finishes are also discovering the proven corrosion resistance of coil coated metals.

Coil coating provides a uniform, consistent coating. Painting metal while flat allows for consistency in film application and color uniformity, so the edge-to-edge and side-to-side variability is virtually eliminated, enhancing long term durability.

The prepainting process also provides advanced corrosion resistance, including cut-edge protection and resistance to underfilm corrosion creepage, and corrosion resistance where nicks and scratches occur.

Cut-edge protection of prepainted parts has repeatedly proven to be significantly better than post-painted parts. The NCCA, along with help from the North American Zinc-Aluminum Coaters Association (NamZAC), tested prepainted metal air conditioning louvers against three types of post-painted louvers. Comparisons made after 16 months, 44 months, and 68 months of exposure to the elements showed prepainted parts were repeatedly and significantly better than the post-painted parts in terms of the corrosion resistance, uniformity of treatment and film thickness.

The study findings conclude that with proper selection of paint and substrate, a prepainted part should provide a cost-effective product with corrosion resistance, beautiful appearance, and durability.