Glossary of Terms

Acid Catalysed Lacquer

A two component (2K) lacquer system that is cured by the addition of a catalyst based on a weak acid solution prior to application. Also known as an AC.

Acid Catalyst

The weak acid catalyst component used to cure an AC lacquer.

Air Displacement

The volume of air (measured in cubic feet per minute or CFM) which is pushed through a pump by the piston.

Bar

The measuring unit of air pressure. 1 bar = 14.7psi.

Blooming

Term used to describe the hazy film or whitening produced when the weak acid in either an AC or PC reacts with the Stearate used as a sanding aid in certain sanding sealers.

Bodying Up

Filling up of the grain in French Polishing or building up the coating with polish in a multi-coat cycle.

BS 476: Part 6 (1989)

The British Standards reference associated with tests which determine a product's ability to resist contributing to fire propagation and also to limit the level of heat generated when subject to a specific heat source. Expressed as a rating between Class O and Class 4, Class O being the highest rating.

BS 476: Part 7 (1997)

The British Standard reference associated with tests which determine a product's ability to resist the spread of flames over its surface when subject to a specific heat source. Expressed as a rating between Class 1 and Class 4, Class 1 being the highest rating.

BS 4800: 1972

A specific set of colour standards typically used as paint references.

BSi

The British Standards Institute – the external verifying body who audit Companies performance against the British Standards they are accredited to.

Burnished

A polishing technique used to increase the gloss level on two pack lacquers.

CFM

Measurement unit of air output from a compressor – Cubic Feet per Minute.

Clean and Touch-up

Revival of the lacquered surface without re-polishing.

Cold Colour

Reference to a colour or shade that is towards the green end of the colour scale. The opposite to red, or ‘warm’.

Cold-spray

A term used to describe a method of applying wax by spray application without having to heat or melt the wax.

Compressor

Machine designed to compress air.

Constant Bleed

A spray system that supplies air to the gun constantly. Typically used with turbine spray units.

Cracking

Fracturing of the coating, primarily as a result of excessive veneer or substrate movement.

Crazing

A network of fine cracks as opposed to lateral fractures with or against the grain, typically caused by poor application practices such as application of hard lacquers over soft lacquers, the use of the wrong thinner or too much thinner and too short drying times prior to re-application.

Denib

The action of slightly ‘flatting’ or sanding between coats of lacquer to aid intercoat adhesion and to remove any slight imperfections in the film.

Dulling Down

Term used to describe the action of reducing the sheen or gloss of a lacquered finish.

EPA

The Environmental Protection Act.

Fad

A ‘wadding pad’ used inside a French Polishers ‘rubber’. Often taken out of the rubber and used to apply a thin coat of polish prior to colouring.

Figure

Naturally occurring coloured markings in timber which are enhanced when a good quality coating is applied.

Filler

Wood filler or grain filler, usually supplied as a paste, which is used to ‘choke up’ or fill minor holes in the timber or the grain. Available in 1 and 2 pack systems, both solvent and waterborne.

FIRA

The Furniture Industry Research Association, which provides information, advice and independent testing on all activities associated with furniture.

FIRA (BS) 6250

A performance testing procedure for coatings to determine resistance to physical damage and chemical attack.

FIRA 5000

A specific standard accredited by FIRA to finishes or systems that meet certain performance criteria which replicate the conditions found in bathrooms and rooms where high water/moisture content prevail.

Fish Eyes

A crater-shaped defect found in the finished film caused by external contamination. Typical sources of the contamination include silicone or wax from other stripping or finishing processes, silicone from aerosol sprays, grease, oil or dirt, and moisture contamination from air lines.

Flash Point

The lowest temperature at which a mixture of vapour in air can be ignited by a naked flame.

French Polish

A traditional finish, based on shellac or varnish, used mainly in the reproduction or restoration of antique furniture. High skill levels are required to use this type of finish.

Gloss

Term used to describe the visual or measured sheen of a lacquer or finish. Typically rated as gloss (80-90%), Satin (45-65%), Semi-Matt (20-40%), Matt (10-20%) and Dead Matt (0-5%). The level of sheen is measured by a gloss meter which calculates the amount of light reflected from the film surface at 60°.

Grain

Natural indentations found in the surface of the timber. Timbers can be ‘tight’ or ‘close’ grained such as Cherry, or ‘open’ grained such as Oak.

Gravity-Feed Cup Gun

A spray gun where the cup holding the lacquer is sat on top of the gun and the lacquer is fed to the tip by gravity i.e. it flows from the cup down through the gun.

HVLP

High Volume Low Pressure – a term used to describe a spray system where large amounts of lacquer are transferred under low air pressures thus providing good transfer efficiencies.

IR

Infrared – a source of heat or radiation which is invisible to the eye and is found between the visible and microwave regions of the electromagnetic spectrum. Drying systems for coatings often use IR as the heat source.

ISO9001

A Quality Management System in accordance with ISO 9001:2000 to provide a set of processes that ensure consistency and improvement of working practices. Which in turn provide products and services that meet customer’s requirements.

ITW

‘In the White’, meaning substrate in its pre-finished form.

Mass Balance

A method of calculating the relationship between the amount of solvent and solids in a solventborne finishing system (refer to Morrells Technical Services for help).

MDF

Medium Density Fibreboard.

NC

Abbreviation for Nitrocellulose – a low performance, quick drying lacquer used mainly on occasional furniture, fittings, pencils and coffins.

NGR

Abbreviation for Non Grain Raising – a term usually associated with stains that do not swell and raise the fibres of the grain when applied to timber.

Non-Convertible Coatings

Term used to describe a coating that undergoes a chemical or physical change during drying and curing that cannot be reversed after it has occurred i.e. the coating cannot be returned to its liquid state. Typical examples are AC and UV lacquers. Also known as Non-Reversible coatings.

Orange Peel

A film defect which resembles the speckled or mottled surface of an orange, typically caused by uneven drying, incorrect coating weights or wrong spray application pressures.

Pantone

A colour reference library containing many hundreds of colours typically used for matching or specifying printing inks.

Papering-Up

The action of sanding a timber substrate after the stripping process to ensure that all remnants of stripper or other contaminants or surface blemishes are fully removed prior to recoating.

Patina

Name given to a stain or ‘stipple’ used to give an antique or aged effect on furniture or coated panels, especially picture frames.

PDS

Abbreviation for Product Data Sheet.

Pot life

Associated with two-pack lacquers such as AC or PU, and is a measure of how long after mixing the two components i.e. lacquer and catalyst/hardener, the coating will remain fluid enough to be used. Typically, this is 36 hours for AC and 2-3 hours for PU.

Precatalyst Lacquer

Also known as PC, Precat and Precatalysed lacquer. A type of single component (1K) lacquer where a weak acid is already incorporated into the formulation with no need for further mixing prior to application.

Pressure Feed

Term used to describe the use of a pressure pot to feed lacquer to a spray gun under air pressure.

PSI

Abbreviation for Pounds per Square Inch. The measurement unit for air pressure from a compressor.

PU

Abbreviation for Polyurethane lacquers, typically supplied as a two-component system comprising lacquer and isocyanate hardener.

Pulling Over

A method of levelling the final film of a shellac or nitrocellulose finish by means of a solvent-damped rubber. The solvents are special blends prepared to soften the film just enough to allow it to be manipulated.

RAL

A colour reference library, originating in Germany, and comprising of several hundred colours often specified by designers and architects.

Reversible Coatings

The term used to describe finishes or coatings which always remain re-soluble in their own solvents i.e. coatings which do not undergo a chemical or physical reaction during drying or curing that cannot be reversed. Also known as Convertible Coatings. Typical examples are nitrocellulose and French Polish.

RFU

Abbreviation for Ready for Use, meaning the lacquer or paint is supplied in a form that can be used without the need for any additional thinners or catalyst.

SDS

Shortened abbreviation for Material Safety Data Sheet.

Shelf-life

A reference to the length of time after manufacture that a product can still be used without any problems assuming it has been stored in its original unopened container in good conditions.

Shelling

Delamination of the coating due to tangentially-cut veneers moving, or the inconsistent lifting of ‘annual rings’ in timber.

Specific Gravity

Also known as SG or Density – measures the weight per litre of a liquid compared to the same volume of water. Used in the testing of lacquers and when calculating the application coverage of a paint or lacquer.

Spiriting out/off

French polishing term used to describe the final removal of oil or surface contaminant to give a superior gloss finish.

Stopping Up

The application of wood filler to fill cracks and holes in the timber. The filler is normally applied and sanded smooth prior to any staining or finishing process.

Stripping

The term used to describe the chemical removal of dried paint or lacquer films prior to refinishing or restoring.

Substrate

Another term for the timber or material surface that will be worked on or coated.

Suction-Feed Cup Gun

A spray system where the cup sits under the gun and sucks up lacquer by suction to the nozzle/tip.

Thermoplastic Film

Term used for coatings that soften or become ‘plastic’ or malleable under heat.

Thermosetting Film

Term used for coatings which are cured or set hard when heat is applied.

Toy Test Certificate

A certificate of product conformity issued to surface coatings which meet the stringent requirements of BS (EN) 71 rendering them suitable for use on children’s toys and furniture. The test determines the levels of potentially dangerous metals and substances in the coating film.

UV Coatings

An abbreviation for Ultra Violet cured films. These are coatings which typically contain no solvents, are 100% solids, and which cure instantly when exposed to UV light.

Viscosity

The measure of a liquids resistance to flow. In layman's terms this means the thickness of the lacquer or paint. For example, grease is viscous or thick whilst water is non-viscous or thinner.

VOC

Volatile Organic Compound.

Volume

A measurement of the amount of space occupied by a substance, often a liquid within a container

Warm

Refers to a colour towards the red or ‘warm’ end of the colour spectrum as opposed to green or ‘cold’.

Wax Finish

A finish generated by the application of a specific wax by the use of fine wire wool onto a finished surface to give either a dulled effect or to improve the feel of the surface.

Waxing In

The process of filling dents or bruises in finished furniture with a hard wax stick usually the same colour as the furniture.

Wet and Dry

Associated with the use of a lubricant such as white spirit, Turps or water when sanding or denibbing.