Coating Defect

A coating defect refers to any physical or chemical imperfection in a protective layer, such as zinc in a galvanizing process. Common defects include "dross" (impurities trapped in the coating), "blisters" (caused by trapped gases), or "flaking" (due to poor metallurgical bonding). In high-quality galvanizing, defects are often traced back to improper surface preparation, such as inadequate phosphating or the presence of decarburization on the substrate, which prevents the zinc from forming a proper intermetallic bond.