Virtually all manufacturers of cable tray systems, whether steel wire basket, aluminum or steel ladder type, offer epoxy powder coat corrosion protection for their products. Often, however, these powder coated finishes are applied after zinc electroplating.
Some NASA research has shown that zinc whiskers can grow through a polyurethane adhesive coating if the coating is not sufficiently thick . It is unclear whether this will also happen with epoxy powder coatings.
It appears that the ideal finish would be an epoxy powder coating over bare carbon steel using stainless steel for electrical bonding. Due to EPA regulation on US domestic electroplating shops, from a manufacturing standpoint, the powder coat process is the same or lower cost as electroplating.
Epoxy powder coat finishes have been shown to be as or more durable than zinc electroplating from a corrosion standpoint while eliminating the toxic waste that is a byproduct of the electroplating process .