Expert advice


Commonly used industry terms explained


Abrasion resistance
Resistance to mechanical wear

The agent used for abrasive blast cleaning, for example sand or grit

Process of soaking up, or assimilation of one substance by another

Catalyst, hardener, accelerator, curing agent, reactor; a material which accelerates a reaction

Acid Number
A numerical index of free acid in an oil or resin

Catalyst, hardener, accelerator, curing agent, reactor; a material which reacts with another material to turn a liquid coating to a solid coating.

Bonding strength; the attraction of a coating to the substrate

Process of attraction to a surface; the retention of foreign molecules on the surface of a substrate

Air cap
Air nozzle; perforated housing for atomizing air at head of spray gun

Air drying
Dries by oxidation or evaporative drying by simple exposure

Air entrapment
Inclusion of air bubbles in paint film

Airless spraying
Spraying without atomizing air, using hydraulic pressure

Resins prepared by reacting alcohols and acids

Surface imperfections of paint having the appearance of alligator hide

Ambient temperature
Room temperature or temperature of surroundings

Amine sweat
A thin sticky film which forms on the surface of a epoxy coat caused by inadequate curing temperatures and/or high humidity

Anchor pattern
Profile, surface roughness

Bottom paint; Paints formulated especially for below-water-line surfaces and structures to prevent the growth of barnacles and other organisms on ships' bottoms


Barrier Coat

Coat used to allow application of a paint which is not compatible with an existing scheme

Refers to the usual larger volume size of a two-pack system - usually the non-activator part. May also refer to any bare surface to be painted

Resing, Film Binder , Vehicle

Biocide-free or Non-toxic
Antifouling biocides are active chemical ingredients that are released from an antifouling paint film to inhibit the settlement and growth of organisms such as weed and barnacles on the bottom of a boat. Biocide-free paint does not contain any active ingredients in the formulation which act in this way. Such products control the growth of organisms by other non-chemical means, such as by physical surface effects (e.g. non-stick surfaces, continuously eroding surfaces), making the surface too difficult to attach to.

Bituminous Coating
Coal tar or asphalt based coating

Blast Angle
Angle to nozzle with reference to surface ; also angle of particle propelled from wheel with reference to surface

Blast Cleaning
Cleaning with propelled abrasives

Discolouration of finished paint due to migration of unwanted species through the paint coating.

Bubbling in dry or partially dry paint film

Whitening, moisture blush, blushing

Viscosity; middle or under (coat)


Bottom Paint
Antifouling; Paints formulated especially for below-water-line surfaces and structures to prevent the growth of barnacles and other organisms on ships' bottoms

Mixing by pouring from one container to another

Forming a skin over a depression

Degree of resistance to cracking or breaking by bending

Ease of brushing

A term used to describe the appearance of bubbles on the surface while a coating is being applied

Bulking agent
Filler, extender ; ingredients added to paint to increase coverage, reduce cost, achieve durability, alter appearance and influence other desirable properties


Carbon Footprint

A measure of the impact our greenhouse gas emissions have on the environment, and in particular on climate change. It can be calculated for a particular product, for a manufacturing site or for any activity we undertake. It is a measurement of all the greenhouse gases produced in units of tonnes (or kg) of carbon dioxide equivalent. AkzoNobel has a clear Carbon Policy setting out targets and ambitions to be achieved by 2015 and 2020

Carbon neutral
A commonly accepted terminology for something having net zero emissions of greenhouse gases (for example, an organisation or product). As the organisation or product will typically have caused some greenhouse gas emissions, it is usually necessary to use carbon offsets to achieve neutrality. Carbon offsets are emissions reductions that have been made elsewhere and which are then sold to the entity that seeks to reduce its impact. In order to become carbon neutral it is important to have a very accurate calculation of the amount of greenhouse gas emissions which need to be offset – requiring calculation of a carbon footprint

Hardener, activator, accelerator, curing agent ; a material which starts a reaction but is not actually consumed in that reaction

Hole shaped like a cat's eye; cratering

Cathodic Protection
Corrosion prevention by sacrificial anodes, usually a zinc alloy

CFC or Chlorofluorocarbons
These are materials which traditionally had many applications, such as use as propellants in aerosols and as coolants in refrigeration units. Known to deplete the ozone layer in the Earth’s stratosphere , most uses have been severely restricted or banned under international treaties e.g. Montreal protocol

Powdering of surface

Slight V-shaped breaks appear in a paint film due to uneven shrinkage through the cross section of a coat of paint

1. Cleaning steel using special hammers
2. Type of paint failure

Chlorinated Rubber
A particular film former used as a binder made by chlorinating natural rubber

Fish eyes; small causer-like depressions in a paint film

Solvent for cleaning paint equipment

Coat Tar Epoxy Paint
Paint made of a combination of coal tar with epoxy resin

Coat Tar Urethane Paint
Paint made of a combination of coal tar with urethane resin

Premature drying causing a spider web effect when spraying, (paint dries before it hits the substrate)

Color Retention
Ability to retain original colour

Ability to mix with or adhere properly to other components

Copper is used in antifouling paint as a biocide. Copper-free paint does not contain any copper (either as a pigment or as part of the polymer)

Decay; oxidation, deterioration due to interaction with environments

Coverage Rate
Non technical number that tells you how much area you can paint with a given volume of material

Splitting; disintergration of paint by breaks through film

Formation of holes or deep impressions in paint film

Shrinking of paint to form uneven surface

A pattern of tiny cracks in the surface of a gelcoat

A particular method by which chemicals unite to form films


Curing Agent
Catalyst, hardener, activator, accelerator, reactor ; a material that reacts with another to convert a liquid coating to a solid coating.

Sagging; excessive flow of paint on vertical surfaces causing imperfections with thick lower edges in the paint film, not as excessive as runs


Degradable biocides
Biocides are chemical ingredients in paint that inhibit the settlement and growth of organisms such as weed and barnacles on the bottom of a boat. Degradable biocides are biocides that break down in water into harmless constituents, for example via hydrolysis or photo degradation. Biodegradable biocides are broken down by microbes in water and sediments

Chemical solution for grease removal

Dew Point
Temperature at which moisture condenses, making painting impossible

A type of viscosity that increases as you agitate the product

Distinction Of Image; measurement of the clarity of the coating by its ability to reflect the image of a given object

Dow Jones Sustainability Index
Launched in 1999, DJSI is a global index for tracking the financial performance of the leading (best 10%) sustainability-driven companies worldwide. AkzoNobel is selected as a member of the DJSI since September 2005

Dry Film Thickness (DFT)
The film thickness of paint after all of the solvent has evaporated from the wet paint

Dry to Handle
Time interval between application and ability to pick up without damage

Dry to Recoat
Time interval between application and ability to receive next coat satisfactorily

Dry Spray
Overspray, bounce back; sand finish due to paint particles being partially dried before reaching the surface

Drying Time
Time interval between application and final cure

Loss of gloss or sheen


The term was coined by the World Business Council for Sustainable Development (WBCSD) in 1992. It is based on the concept of creating more goods and services while using fewer resources and creating less waste and pollution. The reduction in ecological impacts translates into an increase in resource productivity, which in turn can create a competitive advantage. Critical aspects of eco-efficiency are:

  • A reduction in the material intensity of goods or services
  • A reduction in the energy intensity of goods or services
  • Reduced dispersion of toxic materials
  • Improved recyclability
  • Maximum use of renewable resources
  • Greater durability of products
  • Increased service intensity of goods and services

Eco-premium solutions are competitively-priced, high-end products that have more environmental benefits than their mainstream equivalents. This eco-efficiency can happen at any stage of a product’s lifetime – from the extraction of natural resources to manufacturing, end-use and final waste management. For AkzoNobel, as much as 18 percent of our revenue comes from eco-premium products. Our aim is to increase this figure to 22 percent in 2009 and 30 percent by 2015

Environmentally toxic. Ecotoxic substances have potential to cause severe damage if released into the environment or into a specific ecosystem in toxic quantities

Ecological Footprint or Environmental Footprint
A measure of human demand on the Earth's ecosystems. It compares human demand with planet Earth's ecological capacity to regenerate. While the term ‘ecological footprint’ is widely used, methods of measurement vary, although calculation standards are emerging

Electrostatic Spray
Spraying with electric charge attracts paint on surface

This refers to pollutants such as chemicals, particulate matter and other pollutants that enter the atmosphere, e.g. Volatile organic compound (VOCs, emitted as paint dries/cures) or exhaust fumes from internal combustion engines. AkzoNobel new product development programmes are focused on minimising the emissions of VOC and biocides from our antifouling coatings

Emulsion Paint
Water based paint with an emulsified resin vehicle

Pigmented varnish; any hard, glossy coatings

Environmental Impact
An assessment of the possible impact - positive or negative - that a proposed activity such as a new project may have on the environment. The purpose of making such an assessment is to ensure that decision makers consider the ensuing environmental impacts when deciding whether to proceed with a project. The International Association for Impact Assessment (IAIA) defines an environmental impact assessment as "the process of identifying, predicting, evaluating and mitigating the biophysical, social, and other relevant effects of development proposals prior to major decisions being taken and commitments made."

Environmentally Friendly (also eco-friendly, nature friendly, and green)
Goods and services considered to inflict minimal or no harm to the natural world. Labelling of products as ‘Environmentally Friendly’ is largely governed by voluntary codes. In some cases the use of these terms can cause confusion if they are not clearly defined

Wearing away of paint films

To change from a liquid or solid state to a vapour

Filler, bulking agent; ingredients added to paint to increase coverage, reduce cost, achieve durability, alter appearance and influence other desirable properties

External Mix
Spray equipment in which fluid air joins outside of aircap



Reduction in brightness of colour

Device for measuring colour retention or fade resistance

Fallout (Spray)

Feather Edge
Tapered edge

Extender, bulking agent; ingredients added to paint to increase coverage, reduce cost, achieve durability, alter appearance and influence other desirable properties

Any single coat or layer of paint applied to a surface, rather than a 'paint scheme'

Film Build
Dry thickness characteristics per coat

Film Former
A substance which forms a skin or membrane when dried from a liquid state

Film Integrity
Degree of continuity of film

Film Thickness gauge
Device for measuring film thickness above substrate; dry or wet film thickness gauges are available

Fish Eye

Disintegration in small flakes

Non-uniform sheen is noted in irregular areas caused by inadequate and non-uniform priming and resultant loss of vehicle into substrate

Flash Point
The temperature at which a flammable liquid produces sufficient vapour to allow ignition by a small external flame or spark

Flash Rusting
Rapid surface rusting of freshly prepared steel usually caused by rainwater, condensation or grit blasting

Separation of pigment colours on surface

Force Drying
Acceleration of drying time by increasing the temperature and forced air circulation available

Fuel Efficient Antifouling
Reduced fuel consumption (like-for-like vessel usage) relative to when a typical or mainstream antifouling used



The coating of iron and steels with a layer of zinc and iron-zinc compounds, by immersion in a bath of molten zinc.

Galvanic Corrosion
Corrosion of dissimilar metals in electrical contact

Gel Coat
Protective outer resin layer on glass reinforced polyester laminates (GRP)

Gel Time
The time for a liquid to turn to a solid during a chemical reaction.

Sheen; ability to reflect ; brightness.

Gloss Reaction
Ability to retain original sheen.

Greenhouse Gas
These are gases in an atmosphere that absorb and emit radiation within the thermal infrared range. They include gases such as methane, Carbon Dioxide and Ozone . They are essential to the planet in order to maintain temperature; without them the earth would be considerably cooler. However in recent times human activities have increased emissions of these gases, which has lead to the ‘Greenhouse Effect’; where thermal energy is retained in the atmosphere and average temperatures are increasing

The practice of companies disingenuously spinning their products and policies as environmentally friendly, such as by presenting cost cuts as reductions in use of resources. Examples:

  • Focus on one environmental benefit whilst ignoring numerous harmful impacts
  • Appearing to claim external approval when no verification is possible
  • Vague claims, such as 100% natural, even when some components, though natural are actually hazardous
  • Irrelevant claims such as CFC-free, 20 years after CFCs were effectively banned
  • Making false claims, lying
  • Contradiction, e.g. describing a hazardous pesticide as ‘Environmentally friendly’

An abrasive obtained from slag and various other materials.


HAPS or Hazardous Air Pollutant

Name given by the US authorities to the most potent ‘air toxics’, which are thought to cause serious health and environmental problems, such as cancer and/or birth defects in humans etc. The term originated from the US 1990 Clean Air Act, introduced to reduce emissions of certain air toxics from industry

HAPs free
Product does not contain or emit materials defined as Hazardous Air Pollutants

Curing agent, catalyst, activator, accelerator, reactor ; non technical term used to describe the usual smaller part of a two pack system that is added to the "base" to initiate a cure

The agent used for abrasive blast cleaning, for example sand or grit.

Describes a material, substance or activity with the potential to cause harm to man and/or the environment

Heavy Metal
Any metal with a specific gravity of 5.0 or greater. Especially one that is toxic to organisms, such as lead, mercury, copper, and cadmium

High Build Coatings
Paints that can be applied at comparatively high wet film thicknesses.

High Solids
More than 60% of the product is solid matter that will not evaporate in to atmosphere

Pinhole ; skip ; discontinuity.

Level of moisture in the air.


Impact Resistance

A measure of resistance to a blow ; ability to resist deformation from impact.

Intercoat Adhesion
The ability of each coat of paint to stick to the preceding coat.

Intercoat Contamination
Presence of foreign matter between coats.



Kreb Unit

Units of viscosity



Coatings that dry by solvent evaporation.

Uneven colour or sheendifference in dried paint film

Orientation of pigment flakes in horizontal places.

Legislative Bodies
Persons that make, amend or repeal laws

Wrinkling of top coat or lifting of undercoat. Like the action of a solvent paint remover

Low Copper Leaching
Leaching refers to the rate at which a biocide, such as copper, is released from the paint film in order to inhibit the growth of organisms on the bottom of a boat. Antifouling which leaches copper in salt water at less than a steady state leaching rate of less than 10 μg per cm2 per day may be described as low copper leaching or low copper antifouling1
1 Leaching rate as determined by calculation using a mass balance approach

Low odour
Indicates that a paint produces less odour than a standard or mainstream alternative. There are no standards for categorising a paint as low odour

Low solar absorption
A coating designed to absorb less solar energy than standard coatings, typically via the use of low solar absorption pigments. A topcoat designed in this way and used on the exterior of a yacht will result in reduced temperature of the exterior surfaces and of the interior compartments, reducing the load on the vessel’s cooling systems

Low Surface Energy
Coating that repels water molecules (hydrophobic), smooth and/or has elastic properties to which fouling organisms cannot easily attach

Low VOC Indicate that a product produces less VOC than the alternative or mainstream products available for the same use. We consider paints that comply with the most stringent current legislation (i.e. Southern California) to be low VOC as below:-

Antifouling.......................................330g VOC/litre wet paint as applied
Wood Sealer..................................490g/l
Extreme High Gloss Finish ........490g/l
High Gloss Finish.........................420g/l
Interior Finish.................................340g/l
Finish Primer / Surfacer...............420g/l
Primers and Undercoats.............340g/l


Mandrel Test

A physical bending test for adhesion and flexibility

M & R
Abreviation for Maintenance and Repair

A colour that displays different tones (usually a red / green shift) under daylight and synthetic light.

Coverage rate ; square feet per gallon at a given thickness.

Capable of mixing or blending uniformly

Thin coat

Mix Ratio
The (usually volume) mixing ratio for a two or more part product.

Abreviation for Material Safety Data Sheets.

Irregular cracking as in a dried mud puddle


Natural Products

A chemical compound or substance that is produced by a living organism. Often natural products are considered to be benign or harmless, although this is not necessarily the case. For example, snakes produce highly toxic venoms, and certain fungi are poisonous due to presence of toxins inside their tissues


Non-persistent biocide
Biocide that breaks down in to harmless substances in the environment

See Biocide-free

Solid ; non-evaporating ; the portion of a paint left after the solvent evaporates.



Hiding power.

Orangle Peel
Dimpled appearance of dried film ; resembling orange peel.

Transfer of liquid through a paint film or other membrane.

Condition caused by excessive addition of a curing agent to a two-component paint, causes brittleness or amine sweating.

Paint deposited on a surface or object during spraying of another surafce or object.

Rusting ; combination with oxygen.

Ozone friendly
This term is often found on labels and in literature. It typically means that the product does not contain CFC [Chlorofluorocarbon] gases that contribute to the ozone layer depletion



Failure in which paint curls from substrate.

A dipping process for cleaning steel and other metals ; the pickling agent is usually an acid.

Solid colouring agent.

Small blisters resembling 'goose pimples'.

Formation of small holes through the entire thickness of a coating.

Time interval after mixing during which liquid material is usable with no difficulty.


First complete coat of paint of a painting system applied to a surface. Such paints are designed to provide adequate adhesion to new surfaces or are formulated to meet the special requirements of the surfaces.

Product Stewardship
Programme employed by the Marine, PC and Yacht Business Unit of AkzoNobel that aims to protect its employees, customers, the public and the environment by:-

  • Making protection of health, safety and the environment an early and integral part of our product development process
  • Providing high quality and relevant information on the safe use and disposal of our products
  • Being responsive to the concerns of the community, customers, employees and other stakeholders
  • Complying with all legal requirements affecting our operations and our products in the countries in which we do business
  • Actively participating with industry associations in the development of equitable and attainable standards throughout the world

Surface contour as viewed from edge.

Profile Depth
Average distance between tops of peaks and bottom of valleys on the surface.




Curing agent, catalyst, activator, accelerator, hardener.

A material that can be reprocessed and reused following its initial use. Many metals and plastics are recyclable and many regions have the infrastructure in place to reprocess the materials

Degree of light reflection

A material, natural or synthetic, contained in varnishes, lacquers, and paints ; the film former.

Paint film defects in the form of sagging paint in narrow ribbons flowing downwards on vertical surfaces, usually caused by applying the coating above the recommended film thickness or overthinning.

A reddish-brown oxide coating forming on iron or steel by the action of oxygen and moisture.


Sacrificial Anode

An electropositive metal, such as zinc, that protects a more important electronegative part by corroding when attacked by electrolytic action.

Curtaining ; Excessive flow of paint on vertical surfaces causing imperfections with thick lower edges in the paint film, not as excessive as runs.

Paint used to seal the substrate or previous coats and prevent interaction between subsequent coats applied.

Caking ; sediment.

Ratio between the weight of a substance and that of the same volume of water.

Degree of gray tone in a colour.

Gloss level between 10-30% when measured on an 85° head.

Shelf Life
Maximum interval in which a material may be stored in usable condition.

The formation of a tough, skin-like covering on liquid paints and varnishes when exposed to oxygen.

Societal Concern
A rather vague term that may mean different things to different people. UK Health & Safety Executive define as "...the risks or threats from hazards which impact on society and which, if realised, could have adverse repercussions for the institutions responsible for putting in place the provisions and arrangements for protecting people, e.g. the Government of the day. These are often associated with hazards that give rise to risks which, were they to materialise, could provoke a socio-political response. More simply theses are substances in products where public concern exists over their use or where such concern over their use can be anticipated in the future

A liquid in which another substance may be dissolved.

Solving Entrapment If solvents do not evaporate before a paint film cures, they can become trapped within the coating scheme, causes soft paint films, poor gloss and splitting.

Defect where a paint coating fails owing to poor cohesive (internal) strength, rather than poor adhesion. Usually caused by solvent entrapment and/or undercure.

Spot Priming
The priming of small areas of a previously painted surface where the substrate has been exposed.

Spray Cap
Front enclosure of spray gun equipped with atomizing air holes.

Surface to be painted.

The capacity for the planet to replace the resources consumed. A sustainable business implies that it meets the needs of the present without compromising the ability of future generations to meet their own needs. At AkzoNobel we are committed to reducing our impact on the planet and delivering more sustainable products and solutions to our customers

Manufactured; not occuring naturally.



Degree of stickiness.

Abreviation for Technical Data Sheet.

Mobile or softens under heat.

Thermosetting Becomes rigid under heat and cannot be remelted.

Thinner A liquid used for reducing the viscosity of paints.

Thixotropic Defines a type of viscosity that thins as it is stirred or agitated and then sets up again when that agitation stops.

Tie Coat
A coat of paint applied to a previous coat to improve the adhesion of subsequent coats or to prevent other surface defects e.g. bubbling of a subsequent coating.

Profile, mechanical anchorage, surface roughness.

Touch Dry
The stage during drying when the coating no longer feels sticky when lightly touched.

Distilled pine oil, used as a cleaner, solvent or thinner for oil-based and alkyd coatings

Paints based on binders which cure by the chemical reaction between two components.



Not dispersed or broken-up fine enough.

Condition where a paint coating fails to cure properly due to incorrect mixing or application in cold/damp conditions. Paint will stay soft with poor gloss.

An important resin in the coatings industry. A true urethane coating is a two-component product that cures when the catalyst prompts a chemical reaction that unites the components.



A preparation consisting of a solvent, a drying oil, and usually resin, rubber, bitumen, etc., for application to a surface where it polymerizes to yield a hard glossy, usually transparent, coating.

Liquid barrier, binder; anything dissolved in the liquid portion of a paint is part of the vehicle.

A measure of fluidity.

Viscosity Cup
A device for measuring viscosity

The volume of volatile organic solvents in a product. Volatile organic compounds (VOCs) are gases or vapours emitted by various solids or liquids. Paint and paint strippers, along with many domestic products often contain VOCs which are emitted when they are applied or used. VOCs are essential in many Yacht coatings. Topcoats are a key example as they are expected to have excellent aesthetics and hence require excellent flow properties

The defining quality of a liquid that evaporates quickly when exposed to air.

Volume Solids
The volume percentage of a paint that is solid matter.


Water based / Low VOC coating

Coating where primary solvent is water and VOC is less than 150 g/lt of liquid product. (theoretical value, assuming worst case) Benefit: Reduced emissions to air / impact on the environment. No solvents required for clean up of equipment, VOC compliance (where applicable). Aids compliance with SED (where applicable). Low odour. Improved working environment (especially when indoors)

Water Blasting
Blast cleaning using high velocity water.

Water Spotting
A surface defect caused by water droplets.

Weld Slag
Deposits formed during welding.

Weld Splatter
Beads of metal left adjoining a weld.

Wet Edge
Keeping the paint wet enough when it is applied by brush so it can be brushed back into without showing lines of demarcation from one painted area to the next.

Wet Film Thickness (WFT)
The thickness of paint when it is first applied before solvent evaporation takes place.

Wet Rot
Decay of timber by fungi that thrive in moist wood and poorly ventilated areas.

Wet Spray
Spraying so that surface is covered with paint that has not started to dry.

White Copper
Normally referring to an alloy of copper and nickel or copper and zinc, more recently it is being used simply to describe Copper Thiocyanate, which is a white or grey powder used in some antifouling paints as a biocide. Benefit: Antifouling products containing copper thiocyanate often leach copper from antifouling more slowly than those containing a similar quantity of copper oxide

Film in drying stages shrinks into tiny crests and valleys in irregular pattern caused by poor application.




Yellowing of white paints caused by certain gases, cleaning agents, cooking, ammonia washes and by poor selection of pigments and vehicles


Zinc Spraying

Similar to galvanising, molten zinc is sprayed on prepared steel using a special heated spray gun. Zinc sprayed surfaces are difficult to paint satisfactorily

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