Coating Inspection Fundamentals and Safety
The inspector's role and authority
A coating inspector verifies that work conforms to the project specification, not that it is convenient for the contractor. Understand the three-cornered relationship: the owner defines requirements, the contractor performs the work, and the inspector reports conformance. Your product is a factual record - measurements, observations, dates - not an opinion. You do not direct the contractor's workforce, authorize substitutions, or waive a specification requirement; you document the deviation and escalate to the owner's representative. Know the difference between a hold point (work cannot proceed until inspection is released) and a witness or surveillance point.
Specifications and standards
Be able to name the families: SSPC/NACE surface preparation and application standards, ASTM test methods, ISO 8501–8504, and manufacturer product data sheets. When documents conflict, the project specification governs unless the contract states otherwise; the product data sheet governs parameters it alone defines, such as recoat windows.
Safety fundamentals
Coatings work combines chemical, physical, and confined-space hazards. Key numbers: acceptable oxygen 19.5–23.5%; entry is prohibited at or above 10% of the lower explosive limit without further controls; combustible gas and hydrogen sulfide monitoring are required before and during entry. Solvent vapors are heavier than air; ignition sources include static from spray equipment, hot work, and non-explosion-proof lighting. Abrasive blasting generates respirable silica - use supplied-air respirators, not dust masks. Isocyanates sensitize; lead and chromate pigments require hygiene and blood-lead programs. Read the SDS before you enter the space, not after.
Trap: questions offering "the inspector should stop work" as the answer. Unless the contract grants that authority, the correct action is to notify the owner's representative and document the condition.
Rule of thumb: 19.5 / 23.5 / 10 - oxygen floor, oxygen ceiling, LEL ceiling. A reading of 19.0% oxygen is a fail, not a marginal pass.