The coating is a zinc and aluminum type coating - not a paint or powdercoat, etc... Iron Decon certainly could have a bad result on that, and it sure looks like it did.
I've used coated rotors on multiple vehicles - had one on a set of AC Delco's that went for 8+ years and many miles and still looked pretty good - even through Minnesota winters.
I've used coated rotors on multiple vehicles - had one on a set of AC Delco's that went for 8+ years and many miles and still looked pretty good - even through Minnesota winters.