Marine Coatings Inspection Fundamentals
What the inspector is actually for
A marine coatings inspector is the owner's independent evidence that the specified coating system was applied to the specified standard. The job is not to help the applicator pass; it is to record objective readings against acceptance criteria, document deviations, and escalate before a nonconforming layer is buried. Understand the inspection chain: pre-job meeting and specification review, ambient and surface condition checks, hold points at each stage (surface preparation, primer, stripe coats, intermediate and finish coats, final cure), and a final report with traceable readings.
Concepts to know
Know the standard-based framework: SSPC-PA 2 for dry film thickness (DFT) measurement, SSPC-SP COM for surface preparation commentary, ISO 8501-1 visual rust grades and preparation grades (e.g., Sa 2½, St 3), ISO 8502-3 for soluble salt by Bresle method, ISO 8502-6/9 for conductivity testing, and ASTM D4417 for surface profile. Know the roles and limits of authority of the inspector, the coating manufacturer's technical representative, and the owner's representative. Understand hold points, nonconformance reports, and the difference between a specification requirement and a manufacturer's recommendation when they conflict (the more stringent governs unless the owner directs otherwise).
Traps in questions
Watch for questions that blur measurement with acceptance: an instrument reading is data; the specification sets the limit. Another trap is confusing dew point margin (surface temperature must be at least 3 °C above dew point, a common rule) with relative humidity limits (often ≤85%). Also beware of "inspector may waive" options - inspectors document and recommend; they do not unilaterally change the specification.
Worked rule of thumb
If ambient air is 24 °C and RH is 80%, dew point is about 20.4 °C. Surface must be ≥23.4 °C to proceed. A steel surface at 22 °C fails the 3 °C margin even though the air is dry enough - stop and record it.