Glossary of Terms
The following glossary contains terms used commonly in the paint and coatings industry to describe the characteristics, usage and components of paints and coatings. Although fairly extensive it primarily focuses on high performance coatings and industrial or commercial applications.
Abatement: Involves either removal of the hazardous material (lead based paint, asbestos etc.), covering the hazardous surface material with an impermeable surface, or covering it with a heavy-duty coating (encapsulant).
Abrasion Resistance: Resistance to being worn away by rubbing or friction. Abrasion resistance is a matter of toughness, rather than hardness. It is a necessary quality for floor finishes, enamels and varnishes.
Abrasives- sandpaper, sanding screens, diamond grinding wheels, wire brushes, scouring powders, etc. are all used to “de-gloss” or abrade surfaces to provide “tooth” or a mechanical bond as well as to insure surfaces are clean and sound prior to coating application. Most are available in different grits, grades or textures to allow for fast removal of thicker materials or to simply scuff the surface for proper bonding of thinner coating materials.
Acrylic: A synthetic resin widely used as a latex to produce paints with good color and color retention. Acrylic also refers to a coating in which the binder contains acrylic resins. Acrylic latex paints may be thinned and cleaned up with water.
Adhesion: The degree of attachment between a coating film and the underlying paint or other material.
Aggregate: solid particles of varying sizes that are used as additives to coatings for purposes ranging from improved light reflectivity (glass bead) to replicating texture (stucco like wall finishes). In flooring applications frequently used aggregates include sand, silica flour, colored quartz, stone, aluminum oxide, garnet, plastic media, etc. The aggregates can be used for a variety of purposes, such as fillers, extenders, heat sinks, or to provide a decorative, abrasion and or slip resistant finish.
Air Cure: One method by which liquid coatings cure to a dry film. Oxygen from the air enters the film and cross-links the resin molecules. Also called “Air Dry” and “Oxidizing.”
Alkali: A substance such as lye, soda or lime that can be highly destructive to paint films.
Alkyd: A synthetic resin modified with oil, used extensively in the manufacture of paints and varnishes prior to concerns with VOCs. Alkyd paints contain alkyd resins in the binder and must be thinned and cleaned up with solvent or paint thinner. The terms alkyd paint and oil-based paint are generally used interchangeably.
Alligatoring: Paint film cracking that makes the surface look like alligator skin.
Ambient Temperature: the temperature of the air surrounding the surfaces to be finished.
Amide: A functional group which can act as an epoxy resin curing agent.
Amine Blush: a oily film that occasionally appears on the surface of a cured epoxy coating which will interfere with proper bonding of a subsequent coat
Amines: materials often used as curing agents for epoxy coatings
Anchor Pattern The surface profile generated by abrasive blasting. The difference in height, between peaks and valleys of the blast profile.
Back priming: Applying a coat of paint to the back of woodwork or exterior siding to prevent moisture from entering the wood and causing the grain to swell.
Base: A paint or coating that is formulated in a manner that allows the addition of tints or colorants to develop a custom color.
Binder: Solid ingredients in a coating that hold the pigment particles in suspension and bind the particles together into a film, allowing them to attach to the substrate. Consists of resins (e.g., oils, alkyd, latex). The nature and amount of binder determine many of the paint’s performance properties–washability, toughness, adhesion, color retention, etc.
Blast Cleaning: the cleaning and roughing of a surface by the use of sand, artificial grit, or fine metal shot which is projected at a surface by compressed air or mechanical means.
Blast Profile: same as anchor pattern. A cross sectional view of an abrasive blasted surface.
Blistering: Formation of dome-shaped bubbles or pimples in paints or varnish films resulting from local loss of adhesion and lifting of the film from the underlying surface. Blistering is generally caused by moisture in the wood, moisture drive, by paint having been applied before the previous coat was dry, and or by excessive heat during or after application.
Blushing: A gloss film turning flat or a clear lacquer turning white. Blushing is usually caused by moisture condensation during the drying process.
Body: The thickness or viscosity of a fluid.
Boiled Oil: Linseed (sometimes soya) oil that was formerly heated for faster drying. Today, chemical agents are added to speed up the drying process.
Boxing: Mixing paint by pouring from one container to another several times to ensure thorough mixing.
Breathe: A paint or coating that “breathes” allows the passage of moisture vapor through the paint film without causing blistering, cracking or peeling.
Bristle Brush: A paint brush with filaments made up of animal hair strands usually hog hair. Bristle brushes are primarily used for alkyd paints although inexpensive ones are often used as “throw away” brushes for application of high performance coatings where the cost of solvents and time to clean an expensive brush become prohibitive or impractical.
Build: Thickness or depth of paint film when dried- .generally measured in mils (thousandths of an inch).
Catalyst: An ingredient that speeds up a chemical reaction. Catalysts are frequently used in two-component epoxy systems.
Caulk: A flexible (semi-drying or slow-drying) mastic compound used to seal joints or fill crevices around windows, chimneys, etc., prior to or after painting.
Caulking Gun: A tool for expelling caulk from a tube. It enables a “bead” of material to be applied to cracks and seams.
Chalking: Powder formed on the surface of a paint film, which is caused by the disintegration of the paint binder during weathering. The amount of chalking experienced can be affected by the choice of pigment or binder. Epoxy coatings are particularly susceptible to this phenomenon.
Checking: A kind of paint failure in which many small cracks appear in the surface of the paint.
Chemical adhesion – A chemical reaction of two materials that bonds the two together.
Clear Coating: A transparent protective and/or decorative film; used most commonly as the final coat of sealer applied to automotive finishes.
Coalescing: The flowing or melding together of emulsion particles which occurs during film formation of the latex paint drying process.
Coalescent Aid: A small amount of solvent contained in latex coatings. Not a true solvent however, since it does not actually dissolve the latex resins. The coalescent aid helps the latex resins flow together, aiding in film formation.
Coating: A paint, varnish, lacquer or other finish used to create a protective and/or decorative layer. Generally used when referring to high performance paints or specialized materials applied in an industrial setting as part of the original equipment manufacturer’s (OEM) process, or to reduce life cycle costs of industrial infrastructures.
Coating System: Paint products used together to cover the same surface. The film may be the result of primer, undercoat and topcoat (also called finish coat).
Cohesion: A bonding together of a single substance to itself or the ability of a coating to hold together. Internal adhesion.
Colorant: Concentrated color (dyes or pigments) that are added in small proportions to stains, paints or coatings to make specific colors.
Color Chip: A color sample usually consisting of a paint applied to a small piece of card (a chip).
Colorfast: Non-fading in prolonged exposure to light.
Color Retention: The ability a paint or coating exhibits to keep or retain its original color. Major threats to color retention are exposure to ultraviolet radiation and abrasion by weather or repeated cleaning.
Combustible: Able to burn, flammable.
Control Joints: a narrow tooled or straight groove or saw cut in concrete designed to “control” where the concrete should crack.
Corrosion Inhibitive: A type of metal paint or primer that prevents rust by preventing moisture from reaching the metal. Zinc phosphate, barium metaborate and strontium chromate (all pigments) are common ingredients in corrosion-inhibitive coatings. These pigments have a tendency to absorb moisture that enters the paint film.
Coverage: The area over which a given amount of paint will spread at a specified thickness. Coverage, also known as spreading rate, is normally expressed in square feet per gallon (or square metres per litre) at either a wet or dry film thickness.
Cracking: Breaks in the paint film wide enough to expose the underlying surface.
Crazing: Small interlacing cracks in the paint film.
Creosote: A liquid coating made from coal tar once used as a wood preservative. It has been banned for consumer use because of potential health risks.
Cure, Curing: The process whereby a liquid coating becomes a hard film.
Cutting-in The brushing technique that is used when a clean, sharp edge is needed. Cutting-in is needed typically at the intersection of dissimilar materials or at change of color. In example, for a window sash- painting the wood and not the glass or the wall, at the top of a wall- where it meets the ceiling, and or in areas that are hard to reach when using a roller.
Dead Flat: No gloss or sheen.
Dew point: the temperature (surface or air) at which the quantity of moisture in the air (relative humidity) will reach full saturation and at which condensation of moisture will occur.
DFT: abbreviation for dry film thickness.
Diamond Crack Chasers: machines equipped with diamond saw or tuck pointing blades used to open up the joints or cracks in a concrete floor for a clean square shouldered openings need for proper joint or crack repair.
Diamond Grinders: machines used to prepare concrete for coating application or to polish concrete or stone floors. Grinders come in many sizes from large ride on units to walk behind units to 4” hand machines. Diamond grinders are commonly used in conjunction with shot blasters to access areas that are inaccessible to the larger shot blasting equipment. Diamond grinding wheels are available in a wide variety of grits from coarse grades suitable for removal of flooring materials and concrete to super fine grades suitable for polishing stone and concrete.
Diamond Saws: circular saws equipped with diamond blades from large walk behind units to 4” hand machines used to cut new control joints in floors or to provide a positive square shouldered termination point for concrete repairs.
Diluent: A liquid used in coatings to reduce the consistency and make a coating flow more easily. The water in latex coatings is a diluent. A diluent may also be called a “Reducer,” “Thinner,” “Reducing Agent” or “Reducing Solvent.”
Dispersion: Suspension of minute particles in a suitable medium.
Driers: Various compounds or paint ingredients that aid or speed the drying or hardening of the paint or coating film.
Drop cloth or Drop-sheet: A sheet of cloth or plastic used to protect surfaces during painting of nearby areas.
Dry Colors: Powder-type colors to be mixed with water, alcohol or mineral spirits and resin to form a paint or stain.
Dry- dust free: The stage of drying when particles of dust that settle on the surface do not stick to the paint film.
Dry- tack free: The stage of drying when the paint no longer feels sticky or tacky when touched.
Dry- to handle: The stage of drying when a paint film has hardened enough that the painted surface may be used without becoming marred.
Dry- to recoat: The stage of drying when the next coat can be applied.
Drying Time: The period from the time a coating is applied until the time when it attains a specified state of tackiness or hardness.
Drying Oil: An oil that when exposed to air will dry to a solid through chemical reaction with air: linseed oil, tung oil, perilla, fish oil, soybean oil.
Drywall: Any substitute for plaster such as wallboard, plasterboard, gyproc or sheetrock. Drywall typically consists of several thicknesses of fibre board or paper that have been bonded to a hardened core of gypsum.
Earth Pigments: Those pigments that are obtained from the earth, including barytes, ocher, chalk and graphite.
Efflorescence: A deposit of salts that remains on the surface of masonry, brick or plaster when water has evaporated.
Eggshell A gloss range between flat and semi-gloss. The sheen closely resembles the lustre of an eggshell. Note that eggshell is a degree of gloss, not a color.
Emulsion: A mixture of solids suspended in a liquid.
Emulsion Paint: Coating in which resins are suspended in water, then flow together with the aid of an emulsifier. Example: latex paint.
Enamel A broad classification of paints that form an especially smooth, hard film. Enamels may be obtained in a full range of glosses and can be either latex or alkyd (oil). Consumers, however, often associate the term with alkyd (oil-based) products.
Epoxy: Extremely tough and durable synthetic resin derived from petroleum used in some coatings. Epoxies, which are generally cured by catalysts are extremely tough, durable and highly resistant to chemicals, abrasion, moisture and alcohol.
Erosion: The wearing away of a paint film as a result of exposure to the weather.
Etch: Prepare the surface by chemical means to increase the texture or profile of a surface in order to improve the adhesion of coatings.
Expansion Joint: a surface divider joint that provides space for the surface to expand. It is usually composed of a fibrous material (~1/2″ thick) and is often installed in and around a concrete slab to permit it to move up and down (seasonally) along non-moving foundation walls.
Extender: Ingredients added to paint to increase coverage, reduce cost, achieve durability, alter appearance, and influence other desirable properties. Extenders are typically less expensive than prime hiding pigments such as titanium dioxide. Examples: barium sulphate, calcium carbonate, clay, gypsum, silica, talc. Some extenders may also improve coating performance.
Fabric Roller: An application tool made from a high nap fabric and designed to apply paint by saturating with paint and rolling across the surface.
Feather Edge: reduced film thickness at the edge of a dry coating film in order to produce a smooth, continuous appearance.
Feather Sanding: Sanding to taper the edge of dried paint film.
Ferrule: The metal band that connects the handle and stock of a paint brush, holding the filaments or bristles in place.
Filaments: The part of a paint brush that holds and applies the paint. In a natural bristle brush, the filaments are often referred to as bristles.
Filler: A composition used for filling fine cracks and pores to make the surface smooth before paint is applied.
Film: A layer or coat of paint or other material applied to the surface. The layer remaining after the paint has dried is often called the dried film.
Film Build: Amount of thickness produced in an application. Measured either when coating is applied (wet mil thickness) or after it has dried or cured (dry mil thickness) Normally measured in thousandths of an inch (mils).
Film Integrity: the continuity of a coating free of holidays, breaches, pinholes or other defects.
Film Thickness: Depth or thickness of the dry coating in millimeters.
Film Thickness Gauge: a device for measuring either wet or dry film thickness
Finish Coat: the final coat or application of a paint or coating sometimes referred to as the Topcoat.
Fish Eyes: small holes or craters in the surface of a paint or coating. Fish Eyes are generally caused by oil, grease or silicone contamination.
Five in One- a tool that typically includes a sharp blade for scraping, a pointy end for scratching out a crack or as a Phillips head screwdriver, a flat portion that can be used as a slotted screwdriver, a curved portion for cleaning paint rollers, and a metal cap on the end of the handle for setting nails.
Flaking: Small pieces of paint surface coming off the surface. Cracking or blistering usually occurs before flaking.
Flammable: Easily set on fire.
Flash Point: The temperature at which a coating or solvent produces vapors that are capable of being ignited when exposed to a spark or flame.
Flat: A surface that scatters or absorbs the light falling on it so as to be substantially free from gloss or sheen (0-15 gloss on a 60-degree gloss meter) even when the surface is viewed from an angle. A flat finish has even less gloss than an eggshell finish. Flat paint is typically less durable than higher gloss paint.
Flexibility: The ability of a coating to expand and contract during temperature changes.
Flow: The ability of a coating to level out and spread into a smooth film. Paints that have good flow usually level out uniformly with few brush or roller marks.
Fire Resistance: The ability a coating exhibits to withstand fire or to protect the substrate to which it is applied from fire damage.
Fire Retardant: A coating which will (1) reduce flame spread, (2) resist ignition when exposed to high temperature or (3) insulate the substrate and delay damage to the substrate.
Foam Backer Rod: a compressible, closed cell, flexible, round, polyethylene foam filler material that comes in long rolls. It is used to fill the bottom of expansion and or control joints to prevent joint sealants or filling materials from seeping down through the joint and under the slab. Backer rod seals the sides of the joint and allows the joint sealant to bond to the sides of the joint without bonding to the bottom. This will allow for expansion and contraction or movement of the slab without jeopardizing the integrity of joint filling materials.
Foam Roller: A tool that is similar to a fabric roller but made from synthetic foam rubber. It is designed for clear, fine finishes.
Force Drying: the acceleration of drying by increasing the ambient temperature.
Fungicide: An agent that helps prevent mold or mildew growth on paint.
Galvanized: iron or steel that is protected from rust by a thin coat of zinc.
Glazing Compound: putty used to set glass in window frames and to fill nail holes and cracks.
Gloss: The luster or shininess of paints and coatings. Different types of gloss are frequently arbitrarily differentiated, such as sheen, distinctness-of-image gloss, etc. Trade practice recognizes the following gloss levels, in increasing order of gloss: flat (or matte)– practically free from sheen, even when viewed from oblique angles (usually less than 15 on 60-degree meter); eggshell– usually 20-35 on 60-degree meter; semi-gloss–usually 35-70 on 60-degree meter; full-gloss–smooth and almost mirror-like surface when viewed from all angles, usually above 70 on 60-degree meter.
The higher the gloss, the more scrubbable and durable the finish tends to be. Degrees of gloss include flat, velvet, eggshell, low lustre, semi-gloss and high gloss.
Gloss Meter: A device using a standard scale for measuring the light reflectance of coatings. Different brands with the same description (such as semi-gloss or flat) may have quite different ratings on the gloss meter.
Gloss Retention: the ability to retain the original sheen during weathering.
Grain Raising: Swelling and standing up of the wood grain caused by absorbed water or solvents.
Graining: Simulating the grain of wood through the use of specially prepared colors or stains and or the use of graining tools or special brushing techniques.
Hardboard: Reconstituted natural wood that is fabricated by reducing natural wood to fibres and then pressing the fibres together into panels of various thicknesses.
Hardener: Curing agent for epoxies or fiberglass.
HEPA Vacuum: High-efficiency particulate air-filtered vacuum designed to remove lead- contaminated dust.
Hide, Hiding, or Hiding Power: the ability of a coating to obliterate the surface below it.
High Build: a term referring to a coating which can produce a thick film in a single coat.
Hold-out: The ability of a paint film to dry to its normal finish on a somewhat absorptive surface.
Holiday: any discontinuity, bare, or thin spots, misses, skips or voids in a paint application.
Hot Spots: incompletely cured lime spots that bleed through the coating on a plastered wall.
Hydrostatic Pressure- the pressure exerted by a fluid at equilibrium due to the force of gravity or some other outside force. Hydrostatic pressure is a known cause for paint or coating failures. Examples would be a roof leak allowing water to flow into the roof deck, drywall ceiling and downward and now the weight of the water forces it down against the bond line of the ceiling paint causing it to fail. The failure of paint on exterior wood trim could very well fall into this category of failure.
Another example could be with a “slab on grade” concrete floor installed without an adequate moisture or vapor barrier system, which is than coated with an impervious coating system. If the water table rises to the point where the floor is at or below the water level, the pressure exerted by the water attempting to “seek level” pushing the water through the concrete slab and acting against the floor finish would be considered hydrostatic pressure.
Induction, Blush or “Sweat In” Time: the period of time between mixing of two component products and the moment they can be used.
Industrial Paint or coatings: high performance paints or coatings that would normally be used to finish industrial items such as structural steel, concrete, tanks, chemical plants, and pulp and paper mills. Generally these materials have greater chemical resistance, faster drying times and provide lower life cycle costs than regular house paint or conventional materials.
Inert: A material that will not react chemically with other ingredients.
Inhibitor or Inhibitive: primer or other material used to retard rusting or corrosion.
Initiator: A material that initates a chemical reaction causing the base material to cure. Unlike catalysts which are generally mixed in a fixed ratio (i.e 1:1, 2:1, etc.) and cause “cross linking” of the polymers to make them cure, initiators can be used in varying quantities (dosing is typically related to ambient temperatures or the speed desired for the full reaction) and simply “kick start” the reactioin. In example BPO (benzoyl peroxide- yeah sorta like Oxy 5 Acne medicine!) is used as an intiator for methyl methacrylate resins. A more common example of an initiator is creme hardner used in auto body fillers (i.e. Bondo, etc.).
Intercoat Adhesion: the adhesion between two coats of paint.
Intumescence: A mechanism whereby fire-retardant paints protect the substrates to which they are applied.
Intumescent Coating: A coating material which by foaming or swelling forms a voluminous substance when exposed to heat, forming an insulating, protective layer over the substrate.
Jiffy Mixer: special cylindrical mixing tool required for mixing coatings preventing air entrapment.
Joint Cement or Joint Compound: cement used in dry wall construction as a bedding compound for joint tape, as a filler for nail holes or a patching material to repair damage in dry walls.
Joint Tape: special paper tape or fiber glass tape used over joints between panels of wallboard to conceal the joint and provide a smooth surface for painting.
Lacquer: A fast-drying clear or pigmented coating that is highly flammable and dries by solvent evaporation only. Can be reconstituted after drying by adding solvent.
Lacquer Thinner: solvent such as ethyl alcohol, ethyl acetate and toluene that is used for thinning or cleaning up lacquer.
Laitance: an accumulation of fine particles, loosely bonded, on the surface of fresh concrete, caused by the upward movement of water.
Lap Up: an overlapping of layers of paint during the same application. Lap ups occur when a wet edge is too long, not maintained in a wet state, has been allowed to dry or cure for too long a time period, or the material was not laid off. If the paint or coating has dried or cured to a point where freshly applied material will not flow or blend into it, the newly applied material will in essence be an additional coat. The dry film thickness of the overlapped area will well exceed adjacent areas to as much as double the thickness and differences in appearance sheen, opacity, etc.) are likely.
Latex: a water-thinned paint such as polyvinyl acetate, styrene butadiene or acrylic.
Latex-based Paint: General term used for water-based emulsion paints made with synthetic binders such as 100% acrylic, vinyl acrylic, terpolymer or styrene acrylic. A stable emulsion of polymers and pigment in water.
Lay Off: the act of brushing or rolling the paint or coating in long strokes (from ceiling to floor, top of door frame to bottom, etc.) to eliminate runs, sags, pinholes, overlaps, brush or roller marks, railroad tracks and other imperfections. Laying off paints insures that the material has been applied consistently at a uniform wet film thickness.
Lead: A metal, previously used as a pigment in paints. Discontinued in the early 1950s by industry consensus standard, and banned by the Consumer Products Safety Commission in 1978 because of its toxicity.
Leveling: ability of a film to flow out, free from ripples, pockmarks and brush marks after application.
Life Cycle Costs: a method for determining the most cost effective approach for maintaining equipment or infrastructures. In the coating industry Life Cycle Cost is generally measured in the cost per square foot per year of keeping the surface in an acceptable condition.
Lifting: softening and raising or wrinkling of a previous coat by the application of an additional coat; often caused by coatings containing strong solvents.
Linseed Oil: drying oil made from the flax seed. Used as a solvent in many oil- based paints. “Boiled” linseed oil can be used to protect wood from water damage. Sometimes used as a furniture polish.
Lint-free Roller: a fabric roller, designed not to “shed” lint, that is suitable for fine finishes and/or alkyd paint.
Liquid Driers: Solution of soluble driers in organic solvents.
Litre: a metric volume measurement equal to a little more than a quart.
Mar Resistance: The ability of a coating to resist damage caused by light abrasion, impact or pressure.
Marine Paint: Coating specially designed for immersion in water and exposure to marine atmosphere.
Marine Varnish: a varnish that is specially designed for immersion in water and exposure to the elements, including the marine atmosphere. It is often called spar varnish.
Masking: temporary covering of areas not to be painted.
Masking Paper: a kraft type paper that is held in position by a strip of masking tape and used to temporarily protect surfaces adjacent to those being painted.
Masking Tape: easily removable tape used to temporarily cover bands or small areas next to the area to be painted. It is important to remove most masking tapes promptly, because they arelikely to dry out and leave a troublesome residue if left for more than a few days or when exposed to sunlight and heat.
Mastic: a term used to describe a heavy-bodied coating or paste-like materials. Commonly used as an adhesive for floor tiles or sheet goods. Floor adhesive mastic is often applied with a notched trowel. Mastic coatings are typically high build, high performance, industrial coatings.
Material Safety Data Sheet (MSDS): Information sheet that lists any hazardous substance that comprises one percent or more of the product’s total volume. Also lists procedures to follow in the event of fire, explosion, leak or exposure to hazardous substance by inhalation, ingestion or contact with skin or eyes. Coatings manufacturers are required to provide retailers with an MSDS for every product they sell to the retailer. Sales clerks should make MSDSs available to retail customers.
Mechanical Adhesion – An interlocking of two materials because of shape, texture, etc. causing the two materials to remain affixed one to the other. Also known as tooth.
Metallics: paints that include metal flakes in the base to provide a distinctive look.
Methyl Ethyl Ketone (MEK) A low boiling, highly volatile flammable solvent with extremely good solubility for most vinyls, urethanes, and other coatings.
Mildew Resistance: the ability of a coating to resist the growth of molds and mildew. Mildew is particularly prevalent in warm, humid climates.
Mildewcide: an agent that helps prevent mold or mildew growth on paint.
Mineral Spirits: solvent distilled from petroleum for thinning and clean-up of oil based or alkyd paints.
Mix Ratio: the ratio of one component to the other components in multi component materials. Frequently epoxies or other catalyzed materials include a part A and Part B which are mixed in varying ratios to achieve optimal performance. Typically ratios are listed Part A to Part B (i.e. 1:1, one part A to One part B or 2:1, 2 parts A to one part B) with Part A being the resin and Part B being the catalyst.
Moisture Drive: a term use to describe the movement of moisture from hot or warm areas to cold areas. Warm air holds significantly more moisture than cold air and the dominant moisture drive is from hot or humid building components to cold and drier components.
Monomer: Substance composed of low molecular weight molecules capable of reacting with like or unlike molecules to form a polymer.
Muriatic Acid: concentrated hydrochloric acid often diluted and used for etching concrete.
Nail Head Rusting: rust from iron or steel nails that bleeds through the coating and stains the surrounding area.
Nap: the length of the fibers in a paint roller cover. The length of the nap in a roller cover affects the texture or finished appearance of a roller applied finish.
Naphtha: a petroleum distillate used mostly by professionals (as opposed to do-it- yourself painters) for cleanup and or to thin solvent-based coatings. A volatile organic compound (see VOC).
Natural Resins: Resins from trees, plants, fish and insects. Examples: damars, copals.
Nonvolatile: the portion of a coating left after the solvent evaporates; sometimes called the solids content.
OEM: original equipment manufacturer. Manufacturer of equipment or products that factory applies finishes.
Oil Paint: oil-based paint that contains oil as the basic vehicle ingredient and drying oil, oil varnish or oil-modified resin as the film-forming ingredient. Oil paint can be designed for interior or exterior use. It must be thinned and cleaned up with solvent. Pure oil-based paints have largely been replaced by alkyd paints. Most oil paints are being phased out due to increased VOC compliance laws in an effort to reduce greenhouse gases. Note: this term is commonly and incorrectly used to refer to any paint soluble by organic solvents.
Oleoresin: A natural plant product that contains oil and resins. Turpentine is an example.
Opacity: the ability of a coating film to obliterate or hide the color of the surface to which it is applied.
Opaque coating: A coating that hides the previous surface.
Orange Peel: film having the roughness of an orange due to improper roller cover selection, poor roller or spray application.
Oxidation: Chemical reaction upon exposure to oxygen. Some coatings cure by oxidation, when oxygen enters the liquid coating and cross-links the resin molecules. This film-forming method is also called “Air Cure” and “Air Dry.” (Oxidation also causes rust on bare metals.)
Paint: A coating including resin, a solvent, additives, pigments and, in some products, a diluent. Paints are generally opaque, and commonly represent the portion of the industry known as “architectural coatings.”
Paint Remover: A chemical that softens old paint or varnish and permits it to be easily scraped off. Also called “stripper.”
Paint Thinner: see Mineral Spirits
Peeling: detaching of a dried paint film in large pieces. Peeling is commonly caused by moisture, grease or contaminants under the painted surface and is generally related to improper surface preparation or moisture drive conditions.
Penetrating Finish: A finish that sinks into the substrate, as opposed to settling on the surface.
Permeability: the degree to which a membrane or coating film will allow the passage or penetration of a liquid or gas.
Pigment: Insoluble, finely ground materials that give paint its properties of color and hide. Titanium dioxide is the most important pigment used to provide hiding in paint. Other pigments include anatase titanium, barium metaborate, barium sulphate, burnt sienna, burnt umber, carbon black, China clay, chromium oxide, iron oxide, lead carbonate, strontium chromate, Tuscan red, zinc oxide, zinc phosphate and zinc sulfide.
Pinholing: a film defect characterized by small, pore-like flaws in a coating which extends entirely through the film.
Polymer: Substance, the molecules of which consist of one or more structural units repeated any number of times; vinyl resins are examples of true polymers. Most high performance coatings are also examples of polymers.
Polymerization: The interlocking of molecules by chemical reaction to produce very large molecules. The process of making plastics and plastic-based resins.
Polyurethane: coatings ranging from hard glossy enamels to soft, flexible coatings. With thorough surface preparation, polyurethanes provide good to very good adhesion, hardness, flexibility and resistance.
Polyvinyl Acetate (PVA): a synthetic resin largely used as a vehicle for many latex paints.
Polyvinyl Chloride: A synthetic resin used in the binders of coatings. Tends to discolor under exposure to ultraviolet radiation. Commonly called “vinyl.”
Porosity: the presence of numerous minute voids in a cured material.
Pot Life: the period during which a two-part paint can be applied after it has been mixed.
Powder Coatings: coatings that are applied in a dry powder application and than baked to form a contiguous film. Generally factory applied OEM type finishes.
Practical Coverage: the spreading rate of a paint calculated at the recommended dry film thickness and assuming 15% material loss.
Primer: 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.
Profile: the term used to describe the anchor pattern of a surface produced by sandblasting, acid etching, or similar method. Typically measured in thousandths of an inch
Propellant: the gas used to expel materials from aerosol containers.
Putty Knife: a flat-bladed tool for filling cracks and holes with spackling compound.
Railroad Tracks: thick lines evenly spaced running parallel with the motion/track of the paint roller. These lines occur from an excessive amount of paint on the ends of roller covers. Can be eliminate with higher quality roller covers, properly prepared roller covers or by properly laying off.
Recoat Time: the period that must elapse between applications of coats of paint.
Relative Humidity: the ratio, expressed as a percent, of the quantity of water vapor actually present in the air to the greatest amount possible at a given temperature.
Resin: Synthetic or natural material used as the binder in coatings. Can be translucent or transparent, solid or semi-solid. Examples: acrylic, alkyd, copal ester, epoxy, polyurethane, polyvinyl chloride, silicone.
Roller Frame: a paint application tool consisting of a revolving cylindrical cage that holds a roller cover.
Roller Cover: a cylinder with a plastic, phenolic or cardboard core covered with lamb’s wool, felt, foamed plastics, or other materials used for applying coatings.
Ropiness: a stringy look to the paint film. Ropiness is a result of the paint not flowing evenly onto the surface.
Rosin: Natural resin obtained from living pine trees or from dead tree stumps and knots.
Runs: blemishes on the film that are caused by excessive flow of the coating.
Rust Preventive Paint or Primer: the first coat of paint applied directly to iron or steel structures to slow down or prevent rust
Sags: runs or sags in paint film that flows too much during application. Sags are usually caused by applying too heavy a coat of paint or thinning the paint too much.
Sandblasting – A process for cleaning a surface by air- or water-borne sand, prior to painting
Sandpaper: a sheet of abrasive-coated paper that is used for smoothing rough surfaces.
Sash Brush: an straight or angled brush used for cutting-in.
Satin Finish: a sheen that has a somewhat lower luster than a semi-gloss finish.
Scarify: removal of thick coatings or excessive material build ups (concrete, floor mastics, macadam, floor systems, etc.) using a machine equipped with a rotating cage and cutters appropriate to the material being removed. The machine is called a scarifier, a concrete plane or sometimes a surface preparation machine.
Scrubbability: the ability of a paint film to withstand scrubbing and cleaning with water, soap, and other household cleaning agents.
Sealer: a coating used to prevent excessive absorption of subsequent coats into a porous surface.
Seeds: small undesirable particles or granules other than dust that are found in a paint, varnish or lacquer.
Semi-gloss: a degree of gloss that is glossier than low luster or satin but not as glossy as high gloss. Semi-gloss paints are formulated to give this result (usually 35-70 degrees on a 60-degree meter).
Semi-transparent: a degree of ability to hide the underlying surface greater than transparent but less than opaque or solid color.
Serrated Squeegee: a notched squeegee used for applying viscous coatings.
Set Up: the quality of a film that has dried until it is a film. The film is said to have “set up”.
Settling: paint separation in which pigments and other solids accumulate at the bottom of the container.
Sheen: level of gloss or luster.
Sheen Uniformity: the even distribution of luster over a dried paint film.
Shellac: A natural resin coating made from purified lac dissolved in alcohol, often bleached white. Shellac is used to seal and finish floors, seal knots, etc.
Shot Blasting: A process that utilizes a machine and fine steel BBs, referred to as shot, or steel grit to abrasively blast or mechanically clean flat horizontal surfaces (floors).
Silica Sand: clean sand made up of sharp silica particles, not containing dirt or clay, used for abrasive blast cleaning.
Silicone: A resin used in the binders of coatings. Also used as an additive to provide specific properties, e.g., defoamer. Paints containing silicone are very slick and resist dirt, graffiti and bacterial growth, and are stable in high heat.
Skin: a tough covering that forms on paint when the container is not tightly sealed.
Solids: the part of the coating that remains on a surface after the vehicle has evaporated. The dried paint film thickness is influenced by the amount of solids in a coating. Also referred to as Nonvolatile.
Solids content: the amount of solids by weight or volume typically provided as a percentage of the whole. Multiplying the wet mil thickness by the per cent solids will provide the dry mil thickness.
Solvent: Any liquid which can dissolve a resin. The volatile part of oil-based paints or in general terms refers to the liquid portion of paints and coatings that evaporates as the coating dries. Solvent-based thinners are used for thinning and cleaning up oil-based paints.Solvent Entrapment: the encapsulation of solvent within a cured coating due to improper drying conditions; results in a non-continuous film.
In latex paints, water performs similar functions.
Sound Rusted Substrate: a rusted substrate cleaned of all loose rust and other loose materials, but not cleaned to bare metal.
Source Reduction: Steps taken to reduce waste generation and toxicity at the source through more effective utilization of raw materials and reformulation.
Spalling: the erosion of the top or outer surface of concrete or a masonry component (brick, block, etc.) Often the extent of spalling may expose the stone or coarse aggregates found deeper within the material. Generally when spalling occurs, if left untreated, not repaired or replaced the condition will worsen and ultimately suffer a total failure.
Spar Varnish: a marine grade varnish.
Spatter: small particles, droplets or drips of paint that occur during the application of paint.
Spot Priming: application of primer to spots that require additional protection because the old paint has been removed.
Spraying: a method of application in which the paint is broken up into a fine mist that is directed onto the surface.
Spreading Rate: the recommended rate at which a paint or coating should be applied over a surface. Generally listed in square feet (or meters) per gallon (or litre) at a specific mil thickness. Note spreading rates differ substantially with the porosity of the substrate to which they are applied as well as with the thickness they are applied.
Stain: a solution designed to color a surface without hiding it. Solid color and semi transparent stains are available. Stains may be latex or oil-based.
Stippling: a finish made by using a stippling brush or roller stippler on a newly painted surface before the paint is dry.
Streaking te irregular occurrence of lines or streaks of various lengths and colors in an applied film. Streaking is often caused by some form of contamination or settling of solids in the paint or coating.
Strip: to remove old finishes with paint remover.
Stucco: a masonry finish that is usually applied to the exterior surfaces of buildings in place of siding or other materials.
Substrate: any surface to which a coating is applied.
Surface Temperature: the temperature of the surface to be painted
Synthetic Brush: a paint brush with filaments that are made from a non-absorbent plastic material such as polyester or nylon, rather than animal hair. Synthetic brushes are usually used for latex or water borne paints.
Tabor Abrader: an instrument used to measure abrasion resistance.
Tack Rag: a loosely woven cloth that is treated (dipped into a varnish oil and wrung out) to remain tacky. It picks up dust when it is used to wipe a surface.
Tackiness: slight stickiness of the surface of an incompletely dried film when pressed with the finger.
Tannin: soluble natural stain in woods such as cedar.
Tannin blocking: the process of making tannin stains insoluble so they cannot stain the topcoat; e.g., by means of a primer before the topcoat on cedar siding.
Temperature Dew Point Spread: the difference between either surface or ambient temperature and the dew point (the temperature at which air can no longer contain the moisture within it) measured in the air or on the surface. Note: when the temperature and dew point are within 6 degrees of each other, fog is likely and condensation forming on surfaces is not beyond expectation (think cold glass in a warm room). Condensation (even microscopic condensation) on a surface can lead to numerous types of paint or coatings failures.
Texture: the roughness or irregularity of a surface.
Thermosetting: resins having the property of becoming insoluble or hard upon the application of heat.
Thickener: a substance added to a liquid to increase its viscosity.
Thinner: volatile liquid used to adjust consistency or to modify other properties of paint, varnish and lacquer. Thinner is used to thin and clean up paint.
Thixotropes: additives for paint or coatings (aerosol, cabosil, fumed silica, etc.) that thicken the coating, reduce sagging, flatten the sheen and allow the coating to better hold pigments and additives in suspension.
Thixotropy: the property of a material that causes it to change from a thick, pasty consistency to a fluid consistency upon agitation, brushing or rolling.
Tint Base: in a custom color system, the basic paint to which colorants are added; i.e., white or accent base.
Tinting: the final adjusting of a color of paint to the exact shade required. Tinting is achieved by adding small portions of colorant to a tint base of prepared paint.
Titanium Dioxide: White pigment in virtually all white paints. Provides hiding pigment in most paints.
Tooth – The condition of a flat or non-glossy surface, which allows a succeeding coating, film to adhere readily. See Adhesion, Mechanical Adhesion.
Topcoat: a coat designed to provide a “finish” capable of providing protection and color. (Previous coats are referred to as primers and undercoats.)
Touch-up: improving or correcting imperfect spots in a paint job.
TSP: tri-sodium phosphate, a cleaning agent. After the TSP has been dissolved in water (warm or hot water best), the solution is used in surface preparation. (After cleaning with TSP, the surface should be rinsed.)
TSP substitute: a biodegradable, phosphor free, cleaning agent that can be used instead of TSP.
Turpentine: a paint thinner (now all but replaced by mineral spirits) obtained by distilling pine tree secretions.
Undercoat: for unpainted surfaces, the coat between the primer and the topcoat. For previously coated surfaces, the undercoat is applied directly to the old paint.
Urethane: An important resin in the coatings industry that provides a tough, chemical-resistant finish. True urethane coatings are two-component products that cure when an isocyanate (the catalyst) prompts a chemical reaction that unites the components. These are referred to as catalyzed polyurethane as opposed to water born or oil modified. Urethane requires mineral spirits or stronger solvents for thinning and cleaning up (see Polyurethane).
UV Exposure: ultra violet light exposure, generally sunlight. UV exposure can cause color fading, chalking and other appearance or performance related degradations.
Varnish: a liquid composition that dries to form a transparent or translucent finish.
Varnish Stain: varnish that is colored with a dye or colorant. It does not have the same power of penetration as a true stain, and it leaves a colored coating on the surface.
Vehicle: Portion of a coating that includes all liquids and the binder. The vehicle is composed mainly of water, solvents, resins and oils. The vehicle and the pigment are the two basic components of paint.
Velvet: a gloss range between flat and eggshell.
Vinyl: a resin with poor adhesion but good hardness, flexibility and resistance. Vinyl is used in plastics, wallcoverings, wood adhesives, swimming pools, tank linings and marine equipment. SeePolyvinyl Chloride
Viscosity: The property of a fluid whereby it tends to resist relative motion within itself or in simpler terms- the fluid thickness of a product. Viscosity is often referred to as consistency. The higher the viscosity, the thicker the fluid.
VOC: See Volatile Organic Compound
Volatile Matter: the portion of a coating that evaporates after application.
Volatility: The defining quality of a liquid that evaporates quickly when exposed to air.
Volatile Organic Compound: Organic chemicals and petrochemicals that emit vapors while evaporating. In paints, VOC generally refers to the solvent portion of the paint which, when it evaporates, results in the formation of paint film on the substrate to which it was applied.
Volume Solids: Solid ingredients as a percentage of total ingredients. The volume of pigments plus binders, divided by the total volume of all ingredients, expressed as a percent. High-volume solids mean a thicker dry film with improved durability.
Washability: the ability of paint to be easily cleaned without wearing away.
Water Blasting or Jetting: blast cleaning of metal using high pressure, high velocity water.
Water Spotting: defect in the appearance of a painted surface that is caused by water droplets.
Water-based or Water Borne: Coatings in which the majority of the liquid content is water.
Water-based Paint: latex paint.
Weathering: paint film deterioration as a result of exposure to the weather.
Wet Edge: the edge of a painted area which has not set up and remains “workable”. When painting large areas, it is generally necessary to tie in to the edge of a paint film which has been left for an appreciable time. If this can be done by blending this edge with fresh, free working paint, without any lap showing, the film is said to present a wet edge.
Wet on Wet: the technique of painting whereby the second or subsequent coat is applied before the first or previous coat has dried and the composite film dries as a whole.
Wet Sandblasting: the incorporation of water into a sandblasting operation in order to minimize dust or conversely- incorporating sand into a water blasting operation to make the net affect more aggressive.
Wicking Action: a capillary drawing action that brings oil or water to the surface.
Wrinkling: Ridges and furrows that develop in a paint film when the paint dries. Typically results from applying materials too thickly and solvent entrapment.
Xylene: a flammable aromatic hydrocarbon solvent used in epoxies and fast drying alkyds.