AMPP CIP Level 3 key terms

A quantitative method in which a loading fixture is glued to a cured coating and pulled normal to the surface until the coating detaches, giving a tensile stress value and a failure mode description.

The small cylindrical puck bonded to a coating surface for a pull-off adhesion test; the force at which it detaches, divided by its face area, yields the reported adhesion value.

Separation occurring at the interface between coating and substrate, or between two coating layers, leaving no coating on one of the separated faces; usually indicates poor surface preparation or contamination.

Rupture within a single material rather than at a bond line, such as within the coating film, within the adhesive, or within the substrate; generally preferred over adhesive failure at the coating-substrate interface.

A discontinuity or void in a coating film that exposes or nearly exposes the substrate, allowing corrosion to initiate; detected with high-voltage or low-voltage holiday detectors depending on film thickness.

A non-destructive test in which an energized probe is passed over a coating and a spark or audible alarm indicates a discontinuity; used for thicker films where low-voltage wet-sponge testing is unsuitable.

Verification that a coating film is free of gaps, pinholes, and thin spots over the full inspected area, typically performed with spark, wet-sponge, or similar detectors after the film has cured sufficiently.

A tiny hole through a coating film, often formed by solvent escape, air entrapment, or application defects; a type of holiday detectable by continuity testing and significant on immersion service.

The measured thickness of the cured coating remaining on the substrate, determined with magnetic, eddy-current, ultrasonic, or destructive gauges and compared against the specified minimum and maximum.

The thickness of a coating measured immediately after application while still fluid, commonly with a comb gauge; used with volume solids to predict the dry film thickness that will result.

Magnetic film thickness gauges classified by their magnetic principle: Type 1 uses a permanent magnet, Type 2 uses electromagnetic induction; both apply to ferrous substrates and require calibration on the actual surface.

A film thickness instrument that induces eddy currents in a conductive non-ferrous substrate and correlates the response with coating thickness; used on aluminum and similar metals where magnetic gauges do not apply.

The roughness pattern imparted to a substrate by abrasive blasting or surface preparation, described by its amplitude and angularity; it promotes mechanical adhesion and must be within the specified range.

The abrasive-blasted surface texture that a coating flows into and grips mechanically; too shallow reduces adhesion, while too deep can leave peaks exposed through the film.

A reference disc or plate with known surface roughness patches used to visually and tactilely estimate blast profile by comparison with the prepared surface.

All operations performed on a substrate before coating application, including cleaning, degreasing, and abrasive blasting, which establish the cleanliness and roughness needed for adequate coating adhesion.

Soluble chloride, sulfate, and other ionic residues left on a prepared surface, often from marine exposure or blasting; measured by conductivity or test kits because they cause osmotic blistering and premature failure.

Coating failure in which water passes through the film and dilutes soluble salts or solvents trapped at the interface, drawing more water in and forming fluid-filled blisters under osmotic pressure.

Localized lifting of a coating film into dome-shaped raised areas, caused by trapped solvent, osmotic gradients, corrosion products beneath the film, or poor adhesion; classified by size and density for reporting.

Corrosion that spreads laterally beneath a coating from a break or defect, lifting the film and producing rust staining or blisters; accelerated by moisture, salts, and poor adhesion.

The temperature at which air must be cooled for water vapor to condense; coating application is generally prohibited when the substrate surface is at or near dew point because moisture harms adhesion.

The amount of water vapor in air expressed as a percentage of the maximum it can hold at that temperature; it affects drying, curing, and the risk of condensation on a surface.

The temperature of the substrate itself, measured with a contact thermometer, which governs coating cure and condensation risk and can differ markedly from ambient air temperature.

The percentage of a coating's liquid volume that remains as dry film after the solvents evaporate; used to calculate wet film thickness needed to achieve a target dry film thickness.

An extra brush-applied coat on edges, welds, corners, and other hard-to-spray areas, applied before or after the main coat to build film where spray coverage is typically thin.

A primer containing a high percentage of zinc dust in the dry film that protects steel galvanically, sacrificing itself to protect exposed steel at breaks; requires careful topcoating for immersion service.

A technique that makes a metal structure the cathode of an electrochemical cell, using sacrificial anodes or impressed current to suppress corrosion; coatings reduce the current required.

A coating that corrodes preferentially to protect the underlying metal, such as zinc or aluminum-rich systems on steel; effective only where electrical contact and electrolyte paths exist.

A fire-protective coating that swells and chars when heated, forming an insulating carbonaceous layer that slows temperature rise in the protected steel substrate.

Materials and systems applied to structural steel to delay its temperature rise and maintain load capacity during a fire, including intumescent coatings, cementitious sprays, and board products.

The final coating layer in a system, chosen for appearance, weather resistance, chemical resistance, or color; it may also carry special properties such as anti-skid or fire protection.

The first coating applied to a prepared substrate, formulated for adhesion and often for corrosion inhibition or galvanic protection; it anchors the rest of the coating system.

A coating layer between primer and topcoat that builds total film thickness, improves barrier properties, and helps tie the system together; its color often differs to aid thickness and coverage checks.

A thermosetting coating based on epoxy resin, valued for adhesion, chemical resistance, and barrier properties; typically requires a recoat window and may chalk when exposed to sunlight.

A coating based on polyurethane resin, often used as a topcoat for its color and gloss retention and ultraviolet resistance; aliphatic versions resist chalking better than aromatic types.

The time interval after application during which a coating may be successfully overcoated without surface preparation; exceeding it may require abrading the surface to restore adhesion.

Surface preparation by propelling abrasive particles at a substrate to remove rust, mill scale, and old coatings and to create a profile; classified by cleanliness and profile standards.

Removal of oil, grease, and similar contaminants with solvents or detergents before other surface preparation, preventing contamination from being driven into the surface during blasting.