A sharp edge at the meeting of two surfaces at an angle with one
another.
Discolouration of a coating by diffusion of natural timber extractives,
or previous coatings such as bitumen based products.
A hazy bloom to the coating surface, much like the bloom on a grape.
Often associated with a reduction in gloss level.
Unwanted adhesion between adjacent surfaces of articles that develops
when these surfaces are left in contact.
Milky opalescence which sometimes forms as a varnish or woodstain
dries
Build is the visual impression of the coating thickness of a dried
film. Classification of build based on the measurement of the dry
film thickness according to method 5A of ISO 2808 : 1991 is as the
following categories:
Minimal build: mean thickness less than 5µm
Low build: mean thickness 5µm up to 20µm
Medium build: mean thickness greater than 20µm up
to 60µm
High build: mean thickness greater than 60µm
Areas of a wet film where the coating material recedes or 'pulls
away' from the surface.
Areas of a wet film where the coating material recedes or 'pulls
away' from the surface leaving circular gaps in the film.
Areas of a wet film where the coating material recedes or 'pulls
away' from the surface.
Loss of adhesion between applied layers of coating, or between the
coating and the underlying substrate.
The breakdown of the timber substrate as a result of prolonged exposure
to sunlight and rain, resulting in a loose and fibrous surface.
Loss of the natural extractives from the timber surface through
exposure to sunlight and rain, resulting in greying and bleaching
of timbers.
To remove, by use of a fine abrasive, small raised areas or particles
of foreign matter which stand proud on the surface of a coating
film, without breaking through the surface coating.
The inherent resistance of wood to attack by wood destroying organisms.
The term 'durability' used with reference to the classification
for heartwood, according to BS EN 350-2 : 1994. The majority of
sapwood in commercial use is deemed to be Class 5 (Not Durable)
Durability class 1: Very Durable
Durability class 2: Durable
Durability class 3: Moderately Durable
Durability class 4: Slightly Durable
Durability class 5: Not Durable
White powdery substance on the surface which is the result of soluble
salts within the substrate migrating to the surface.
The ability of a coating to stretch with the substrate as it swells
or shrinks.
Substance which is not part of the cellular structure of wood and
can be dissolved out.
Substance which is formed within the cell structure of wood and
is mobilised by heat.
Areas of a wet film where the coating material recedes or 'pulls
away' from the surface leaving circular gaps in the film.
Pigments form globules due to non-uniform pigment dispersion and
spots of colour are noticeable.
The underlying substrate shows through the most recently applied
coating. This can happen with an opaque coating, or with a woodstain
system if the existing coating/timber and the top coat differ greatly
in colour.
The central core of a tree, consisting of non-functioning tissue
which is rich in tannins/extractives. The heartwood is often darker
than the outer sapwood and generally denser and less absorbent.
See 'Build'
A term applied to coating materials in which, by the choice of suitable
ingredients, the content of volatiles (solvents) present is kept
to a minimum, consistent with the maintenance of satisfactory application
properties.
Permanent reminder of the point where branches began to grow from
the trunk of the tree
See 'Build'
See 'Build'
See 'Build'
Often termed 'microporous', the property of a coating to allow the
passage of moisture in the form of vapour, not liquid, into and
out of the substrate.
See Moisture Vapour Permeable.
Not translucent or transparent, i.e. a coating which will obliterate
the colour of the underlying surface to which it is applied.
The surface of the dried coating film resembles the skin of an orange.
This effect is often the result of the use of a roller for the application
of a coating, particularly if it is rolled out thinly and unable
to level out to a smooth film.
Movement and tears of coating soon after application to vertical
substrates. In severe situations, also known as 'curtains'.
The outer wood in a tree, just beneath the bark in tree trunks.
This is the living tissue in a tree.
This refers to products in which the main solvent carrier is an
organic solvent, usually white spirit.
Allowing light to pass through partially. In terms of a coating,
a translucent or semi-transparent coating is one through which the
underlying substrate remains partially visible.
Product in which the main solvent carrier is water.
A term used to describe the surface finish of a dried paint film
having the appearance of a wrinkled and aged skin. This is the result
of excessive thickness of coating so that the surface dries, forming
a skin, while the coating remains wet beneath.
Volatile Organic Compound. Definition - Any organic compound with
a boiling point (or initial boiling point) lower than or equal to
250oC, at normal conditions of pressure, which participates in atmospheric
photochemical reactions.
|
Ask
Our Experts
Glossary
