The effect of abrasion on a painted surface is to wear away the
This refers to a synthetic resin which forms an important component
in water-based coatings.
Refers to the ability of a paint film or coating to attach itself
to a surface.
Refers to the presence of air bubbles in wet paint.
Refers to a product that uses compressed gas to spray. These are
most commonly found in aersol cans.
A molecular substance that can combine with a proton to produce
a new compound such as a soap.
Is a synthetic resin modified with oil. This forms an important
binder component in solvent based paints.
Refers to the cracking of a painted surface
Composed basically from fibre and cement and is used for making
a wide variety of goods including flat and corrugated sheets, roof
tiles and rain water gutters.
Refers to the black residue from the distillation process of petroleum.
Commonly known as asphalt.
These are termed “swollen” areas, which may be visualised as bubbles
or lifting of the paint film from the surface beneath. This is an
indication of a surface problem, which is a result of localised
loss of adhesion.
Refers to a milky appearance on the surface of a paint film and
is usually a result of an incorrect balance of thinners in the paint
formulation or the rapid evaporation of thinners from the coating.
Refers to a milky appearance on the surface of a paint film usually
caused by the condensation of water on the surface.
This term is often used to describe the thickness or viscosity of
Refers to a low viscosity resin solution, which is used to bind
loose particles on a substrate.
There are various types of building blocks, for example, breeze
blocks and concrete blocks. Breeze blocks contain a large amount
of furnace clincker, which if saturated with water, will pose paint
problems. Concrete blocks are composed of sand, cement and aggregate
and may bary in texture.
These are composed of hardboard and softboard. See hardboard and
Substance whose presence increases the rate of a chemical reaction,
e.g., acid catalyst added to an epoxy resin system to accelerate
Cement roof tiles
The composition of cement roof tiles is similar to that which is
covered in cement plaster except that the tiles are moulded and
coloured with an oxide pigment such as red oxide.
This is a phenomenon usually caused as a result of natural elements
destroying the binder of the paint so that the pigment comes away
as powder on the surface or substrate. All paints are degraded this
way and is only considered as a problem when this phenomenon takes
place too quickly.
This refers to surfaces likely to be contaminated with chemicals
such as acids or alkalis after painting.
Refers to a building board consisting of wood chips and fibres bound
with a resin and compressed under high pressure during manufacture.
Sometimes such boards are veneered. Chipboard is usually recommended
for interior use.
This term is associated with colour and refers to the degree of
saturation of a hue.
Refers to colour concentrates (dyes or pigments) that can be added
to base paints to create various colours.
Non-fading in prolonged exposure to sunlight.
Concrete is composed of aggregate, water and cement. Aggregates
are usually made up of fine or coarse particles, or from graded
particles such as crushed stone sieved to produce the require size.
See water staining
Refers to a reddish coloured ductile metal. On exposure a green
verdigris develops on the surface which protects the copper from
Timber previously dipped or painted with creosote, which is a derivative
of tar oil. Creosote like bitumen, will badly discolour any solvent
based paint systems applied over it during its early life. and can
only be painted with bituminous paint or bituminous aluminium.
This refers to a substrate, which has imbibed water and usually
leaves a moist surface. Moisture in walls, ceilings and timber surfaces
can cause a variety of problems such as blistering, flaking or even
staining of the paint film.
When wood is exposed to the weather for long periods the cellular
structure of the surface breaks down leaving a surface which is
very dry and fibrous.
Dirt pick up
Refers to the tendency of a coating to attract soiled material which
may not be easily removed by simple washing.
Refers to the tendency of a coating to retain soiled material.
Unless one takes precautions, paint applied over bitumen will develop
brown stains because the relatively volatile components of tar or
bitumen will permeate and migrate through the paint. Pigment and
dyes used in some paint formulations are not colour fast and not
intended for exterior use. If these are used outside they will fade.
Also the alkali and moisture in newly plastered walls or new concrete
can react with paint pigments and cause colour changes.
Efflorescence refers to fluffy, white salt deposits that are leached
out through plaster as water passes through it.
Refers to the semi - gloss level of a coating.
Coating in which resins are suspended in water, and are brought
together with an emulsifying agent, example latex paint.
Paints that dry to a hard, usually glossy finish eg paint used to
Very tough, durable and resistant synthetic resin used in specialized
Refers to a lightweight cellular plastic material available in block
form and in various tile sizes.
Eg iron and steel
See glass fibre.
Compositions used to fill surface indentations, cracks etc, in order
to produce a smooth level surface prior to painting.
Refers to the thickness of the dry coating in millimeters.
Fineness of grind
Refers to the measure of the degree of dispersion. A grind gauge
is used for this assessment.
Refers to small holes on the surface of a coating, which is usually
a result of the presence of oil, grease or silicone contaminant.
Refers to when the paint film does not adhere to the wall, but “flakes
off.” This phenomenon may be a result of a chalking surface or due
to a poorly prepared substrate.
Generally refers to a matt surface.
A proprietary name for decorative laminate sheets and other plastic
products. Laminates are widely used for working tops and as a facing
for kitchen furniture.
See mould and organic growth.
Refers to glass which is melted and drawn out into extremely fine
fibres, which are then spun or woven into a tough, light material.
A combination of glass fibre is them combined with polyester resin
and moulded into various shapes. This is now called fibre glass
which is widely used in the manufacture of boats.
Refers to how shiny a paint coating.
Refers to the visual appearance of a surface and depends on the
angle at which light is reflected of a coating to the observer.
Coatings vary from matt to high gloss. A gloss metre is used to
determine scientifically the accurate gloss level of a coating.
Gypsum boards are composed of a layer of gypsum plaster between
two sheets of cardboard.
Gypsum plaster is produced from gypsum rock. Gypsum is basically
calcium sulphate and water.
This refers to the hardness of a paint film on drying. The test
here is that by exerting a measurable pressure, no permanent mark
or damage is left on the coating.
Are composed of compressed bonded fibres. These boards are rigid
and can only bend to a limited degree. The outer surface is usually
plain and smooth.
This is a measure of the opacity of a coating and is the ability
of the coating to obliterate the substrate. Hiding power can be
measured using a controlled test method.
See building blocks & rhinoboards
These are hard cross-grained disfigurements in timber which are
formed where shoots on trees are developed into branches. The resin
ducts in the timber run parallel to the growth and resin in the
knots flow to the surface of the timber. The exposed surface of
the knot must be sealed before paint is applied.
Is a general term used for many fast drying paints which dry purely
by solvent evaporation. Paints such as Dulux Duco spray are called
A general description of a wide range of composite boards such as
This refers to the rising of a dry paint film on application of
the second coat. The paint film actually detaches itself. This phenomenon
is visible when for example paint remover is applied to a paint
An inexpensive coating which can be applied directly to cement surfaces.
Quicklime is the base material and is made from limestone or chalk.
To make limewash, the quicklime is slaked with water and while hot,
tallow or wool grease is stirred in to form the binding.
A hard wood which is durable and is use often for high class joinery,
shop fitting etc.
The ability of a coating to resist damage such as abrasion or impact.
Mould and organic growths
Moulds, algae, lichens and similar organic growths originate from
spores distributed in the atmosphere. These spores settle on any
surface and germinate. Further growth depends on the nutrients and
moisture being available. On the interior surfaces, damp, poorly
ventilated conditions encourage growth. Mould is usually dark brown
or black and is sometimes white. Algae and lichens may be black,
green, yellow, orange and red. Growth may appear as a surface infection
or may be present under painted surfaces and in the substrate, which
may grow through the paint coating.
No pick up time
This term is generally used when discussing road -marking paint.
No pick up time is the time lapse between the application of a film
of road-marking paint and the exact moment when the paint film is
no longer removed, using a standardised measuring instrument.
Eg brass, copper, aluminium and lead.
The portion of a coating left after the solvent evaporates.
A durable hardwood of importance in structural timbering. Joinery
and furniture manufacture. Oak is usually varnished to retain its
The degree of obliteration of a substrate.
This phenomenon is visualised as a mottled finish (like an orange
peel) on the surface of a coating. This may be due to poor paint
flow or too thick a coating applied for example.
A product or chemical that softens old paint or varnish and is easily
Visualised as small holes in the paint film. This may be caused
due to moisture in spray lines or solvent entrapment.
Can be concrete or gypsum based. Plaster consists predominantly
of cement and sand, and may also contain lime. Depending on its
exact composition, new plaster tends to be quite alkaline.
Made by bonding three or more thin layers of wood (plys) with the
grain of each sheet laid at right angles to the previous sheet.
This gives the finished sheet stability and great strength.
Concrete formed into various shapes and profiles prior to erection
on site. The wet concrete is poured into suitably shaped moulds
and strengthened where necessary with steel mesh and rods.
Has several functions. They adhere to the surface and generally
dry with a matt finish that gives a key for the next coat of paint.
Some protect metal surfaces from corrosion while others seal porous
materials, such as softwood and brick, which may otherwise absorb
too much of the paint binder.
Stains migrating through a paint coating from decomposed resin,
normally from the knot. Resin streaks in timber will also bleed
through paint coatings.
A material produced by the coagulation and drying of the latec which
is contained in some species of trees. Because of its extreme elasticity
this material is not suitable for painting with ordinary decorative
Applies to ferrous metals such as iron and steel which have rusted
and require painting.
Saponification refers to alkali attack on the binder a paint and
usually takes the form of blisters on the paint film. Blisters form
in poor adhesion areas of the film. Very often a yellow oil-like
substance is exuded from these blisters.
A coating whose main function is to “seal” in, for example, alkali.
A low- mid gloss coating.
Refers to the formation of an insoluble layer of hardened paint
on the top of the “liquid” paint in a can.
A corrosion resistant type of steel which does not require protection
and is not normally painted.
An important constructional material which is basically iron with
impurities removed. It combines great strength with hardness and
The state of drying when slight pressure is applied with the finger
and leaves no imprint on the coating or is not tacky. Surface dry
can also be tested using a standardised method.
Paints which either textured by adding aggregates so as to form
a rough surface or thick paint sponged or stippled so as to form
A volatile organic liquid used to reduce viscosity of paint and
is often a blend of solvents.
White pigment component of a paint that provides opacity.
This is the coat that will be seen. It provides colour, texture
and protection to various surfaces when applied correctly.
See surface dry.
A layer of paint that masks surface discolouration adheres well
to the previous coating whilst also providing a good key for top
Refers to any surface which is in such a condition that normal preparation
will not provide a satisfactory surface for painting.
Refers to a timber surface painted with an alkyd or polyurethane
A measure of a fluid’s ability to resist flow (how thick or thin
a paint is.)
Normally occurs on exterior cement surfaces freshly painted with
emulsion paint (PVA’s etc.) It is brought about either by condensation
or light rain. The water present extracts water-soluble matter from
the film and after evaporation leaves behind slightly glossy discoloured
streaks on the surface.
A general term, which can refer to ceiling white or limewash.