COATING INSPECTIONS

What Coating Inspection Covers

Coating inspection is the independent checking of a protective coating job from the bare steel right through to the final cured film. A paint system is only as good as the way it goes on, and most of the things that shorten its life happen before anyone notices a problem. Our job is to be on site at the hold points, witness the work against the specification, and record the evidence so the system actually performs for the design life it was sold on. When a coating is done right and inspected properly, the next person to think about it is whoever does the survey years later.

Surface Preparation and Conditions

The single biggest cause of early coating failure is poor surface preparation, so that is where we start. We check the cleanliness of the blasted steel against the grade in the spec — commonly Sa 2½ to ISO 8501 — and confirm the surface profile suits the product being applied. Contaminant checks such as soluble salts are run where the service demands it. Alongside that we record the ambient conditions: air temperature, surface temperature, relative humidity and dew point. The steel has to sit a safe margin above dew point before and during coating, because a film of moisture you cannot see will wreck adhesion. These climatic and preparation checks follow the AS 3894 series.

Film Thickness and Adhesion

Once coating starts we check wet film thickness as the applicator works, then dry film thickness against the spec after each coat has cured. Too thin and the protection falls short; too thick and some products crack or fail to cure. Adhesion testing confirms the coating is keyed to the steel and to itself between coats. For linings and anything in buried or immersed service, holiday detection passes a charge across the film to find pinholes and discontinuities where the substrate is exposed — the kind of tiny fault that lets a tank lining fail from a single missed spot.

Standards and Specification

Site testing is carried out to the AS 3894 series, which covers dry film thickness, adhesion, holiday detection and the dew point and climatic conditions on the day. Coating selection and durability are read against AS/NZS 2312, the guide to protecting structural steel from atmospheric corrosion, and ISO 12944, which sets out paint systems by corrosivity category from C1 through to CX. Surface preparation grades come from ISO 8501. Every report ties back to the project specification, so you can see at a glance what was required and what was measured.

The Value of Independent Coating Inspection

An independent, third-party coating inspector works for the asset, not the applicator. That matters because once a problem is painted over it is invisible until it fails, often in a spot that is awkward and expensive to reach. Catching a low dry film thickness reading or a marginal dew point margin at the time means a quick fix on the day rather than a full strip-and-recoat down the track. The same discipline carries across to our storage tank inspection work, where lining integrity is the difference between a tank that holds and one that leaks.

Why Choose APEC Inspection

APEC Inspection is a NATA-accredited inspection body, and our coating inspectors hold recognised certification such as AMPP/NACE or ICorr. We turn up with calibrated gauges, witness the work at the hold points, and give you clear reporting that stands up with clients, regulators and insurers. Coating inspection sits alongside the broader NDT we run, including visual inspection of surface condition, and we mobilise across Newcastle, the Hunter and nationally. To get a job booked in, request a quote or call the team directly.