Imperfect Science: Improvements in Corrosion Detection in Professional Painting Reply

“This is bad news, Hal.” The contractor looked up from his plans and walked over. Luke was crouching, inspecting the rivets and bolts at the base of the complex valve system that delivered chemicals from transport trains into the factory. Luke continued, “There’s corrosion all over this system. Normally, that might not be a big deal, but it looks like someone else kept painting over the damage instead of fixing it. Look at this!” Luke ran a magnet over the painted surface. At some points, the magnet held tight to the coating, but at other points, the magnet fell to the floor. Even through the top level looked well-painted and clean, the substrate underneath was telling a different story.

Hal protested, “Come on, Luke. It looks fine from here.” Luke continued his objection: “The metal under the paint is in bad shape and it’s likely getting worse. Maybe it holds up ten more years…or maybe it starts falling apart next week. If you insist on doing the work without addressing the underlying problem, then I suggest you find another painter. I’m not doing it.”