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Glossary: Concrete and Epoxy Terms

 
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A

Abrasion Resistance
The ability of a coating to resist degradation due to mechanical wear.

Abrasive Blasting
The operation of cleaning or preparing a surface by forcibly propelling a stream of abrasive material against it.

Abrasive Media
The material used in abrasive blasting to remove surface contaminants. Examples of abrasive media are sand, iron shot, crushed iron slag, glass beads.

Accelerator
A substance used in small proportions to increase the speed of a chemical reaction and thereby reduce the gel time and cure time. Accelerators are used to hasten the curing of a resin system. Another term is promoter.

Acid Etching
Application of an acid (usually muriatic) to effect the chemical removal of cement paste to clean and condition concrete surfaces prior to application of thin-film sealers or coatings.

Acrylic
A synthetic resin used in high-performance water-based coatings. A coating in which the binder contains acrylic resins.

Acrylic Latex
An aqueous dispersion of acrylic resins.

Acrylic Resin
A clear resin attained by polymerizing various acrylic monomers either alone or in combination.

Acrylic Urethane
A two-component chemistry used in seamless flooring systems, containing solvents generally used as a topcoat. Clear acrylic urethane systems are known to shield some of the UV light that has a tendency to turn epoxies amber.

Activator
The curing agent of a two component coating system.

Adhesion
The degree of attachment between a coating or topping and the underlying material to which it is in contact (substrate).  
The ability of dry paint to remain on the surface without blistering, flaking or cracking. Adhesion is probably the single most important property of paint.

Adsorption
The degree to which a surface allows liquid penetration.

Aggregate
A blend of various sized granular materials used to bulk up or extend resinous industrial floor toppings or linings, i.e., abrasives, quartz, granite, pea gravel, walnut shell, graphite, etc. Aggregate may also refer to colored sand and stone used in decorative floors other than Terrazzo. See Chips.

Air Drying
Curing of single component resins wherein drying takes place by oxidation or solvent evaporation by simple exposure to air without a hardener or catalyst.

Air Entrapment
The capture of air bubbles in resinous coatings systems.

Air Release
Most laminating resins, gel coats and other polyester resins might entrap air during processing and application. This can cause air voids and improper fiber wet-out. Air release additives are used to reduce such air entrapment and to enhance fiber wet-out.

Alkali
An aqueous liquid which has a pH value of between 7 and 14. A base or caustic material.

Alligatoring
Surface imperfections of a coating film having the wrinkled appearance of alligator skin. Usually caused by the applied coating reacting with or “lifting” an existing surface coating or sealer.

Ambient Temperature
Room temperature or the existing temperature of the surroundings.

Amine
Materials often used as curing agents for epoxy coatings.

Amine Blush
See "Blush."

Anchor Pattern
The surface profile generated by abrasive blasting or some power tool cleaning. The distance between peaks and valleys of the blast profile.

Aromatic Hydrocarbons
A class of relatively strong organic solvents which contain an unsaturated ring of carbon atoms. Examples are benzene, toluene and xylene.

Art Marble
Artificial Marble; Precast terrazzo.

Asphalt
A black resinous material of petroleum origin.

ASTM
American Society for Testing and Materials.

ASTM D 4258 Standard practice for surface cleaning concrete for coating.
This practice includes surface cleaning of concrete to remove grease, dirt, and loose material prior to the application of coatings. Procedures include broom cleaning, vacuum cleaning, air blast cleaning, water cleaning, detergent water cleaning, and steam cleaning.

ASTM D 4259 Standard practice for abrading concrete.
This practice includes surface preparation of concrete to prepare the surface prior to the application of coatings. This practice is intended to alter the surface profile of the concrete.

ASTM D 4260 Standard practice for acid etching concrete.
This practice includes surface preparation of concrete to prepare the surface prior to the application of coatings. This practice is intended to alter the surface profile of the concrete.

ASTM D 4261 Standard practice for surface cleaning concrete unit masonry for coating.
This practice covers surface cleaning of concrete unit masonry to remove dust, dirt, mortar spatter, oil, and grease prior to the application of coatings. Procedures include vacuum cleaning, air-blast cleaning, water cleaning, detergent water wash, steam cleaning and mechanical cleaning. This practice is NOT intended to alter the surface profile of the concrete masonry units but to clean the surface.

ASTM D 4262 - 83 Standard test method for pH of chemically cleaned or etched concrete surfaces.
This test method covers the procedure for determining the acidity or alkalinity of concrete surfaces prepared by chemical cleaning or etching prior to coatings.

ASTM D 4263 - 83 Standard test method for indication of moisture in concrete by the plastic sheet method.
This test method is used to indicate the presence of capillary moisture in concrete.

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B

Barrier Coat
A coating used to isolate a paint system either from the surface to which it is applied or a previous coating for the purpose of increasing adhesion or insuring compatibility.

Binder
The nonvolatile portion of the vehicle of a coating which holds together the pigment particles.

BITUMASTIC®
BITUMASTIC® is a century + year old trade name that has now become synonymous with coatings made from coal tars and blends of resins, such as epoxy. These products have been used to line water tanks, sewage tanks, coat the interior and exterior of buried pipe and for protection of equipment subjected to water immersion.

Bituminous Coating
A coal tar or asphalt based coating material usually used in thick films.

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. See SSPC.

Blast Profile
See anchor pattern. A cross sectional view of an abrasive blasted surface.

Bleaching
The fading of a color toward white generally caused by exposure to chemicals or ultraviolet degradation.

Bleeding
The diffusion of color matter through a coating from underlying surfaces causing color change.

Blistering
The formation of blisters in toppings or coatings by the local loss of adhesion and lifting of the film from the underlying substrate. On concrete surfaces, this is often caused by moisture vapor transmission problems.

Blooming
A haziness that develops on coated surfaces caused by the gradual discharge of a component of the coating.

Blushing
A film defect which manifests itself as a milky appearance which is generally caused by rapid solvent evaporation or the reaction of the amine component of the coating to the presence of excessive moisture during the curing process. Also, “Amine Blush.” Common in some epoxy systems.

Bond
This represents the state of adhesion between the coating and the substrate. Its strength will depend on the details of the spraying process and the materials used. Bonding mechanisms may be mechanical, physical, chemical or metallurgical or a combination of these.

Bond Coat
A coating applied as an intermediary between the main or top coating and the substrate in order to improve the bond strength and/or to provide a corrosion or oxidation barrier

Bond Strength
The strength of the adhesion between the coating and the substrate. A number of test methods are in use to measure the bond strength of coatings.

Bonding
The attachment between a coating film and the underling material to which it is applied.

Bonding Agent
Material used to increase adherence of coatings or toppings to the existing surface. Also the agent used to bond new concrete to old. May be an acrylic latex, epoxy, polyurethane or other type of adhesive. See “Primer.”

Bounce Back
The rebound of atomized paint from the surface to which it is being applied, especially when applied by conventional air spray methods.

Boxing
Mixing of coatings by pouring from one container to another.

Bridging
The formation of a coating over a depression or crack., e.g. crack bridging.

Brittleness
The lack of resistance to cracking or breaking of a paint film when bent or flexed.

Broadcast System
A means of protecting a concrete floor and having the same attributes as slurry systems, but using clear resins and decorative aggregates, like colored quartz. The added aggregate is an inexpensive way to build thickness and skid resistance.

Broken Marble
Fractured slabs of marble (not crushed by machines into chips). A flooring methodology of combining these broken pieces into a single unit is called "Palladiana" .

Brushability
The ease of applying a coating by brush.

Bubbling
A temporary or permanent film defect in which bubbles of air or solvent vapor are present in the applied film.

Build
The wet or dry thickness of a coating film.

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C

Calcium Chloride Test Method
The recommended method for testing the moisture vapor transmission rate (MVTR) of a concrete slab. This method results in a quantitative measurement of MVTR in pounds per 1000 square feet over 24 hours. The industry standard is that a slab have a MVTR of 3 pounds or less per 1000 square feet of concrete in a 24-hour period before it is acceptable to apply an impervious floor topping.

Carbomate
A white, "milky" formation caused by the reaction of the amine component of an epoxy system to the presence of moisture or humidity during the curing process. The degree of whitening is proportionate to the water exposure. See also "Amine Blush."

Catalyst
An accelerator, activator or agent which chemically increases the rate of reaction in a coating.

Caustic
A strong base or alkaline material.

Caustic Soda
A common name for sodium hydroxide, a strong base or alkali.

Cellosolve
Proprietary name for ethylene glycol monoethyl ether. A slow evaporating, water miscible, relatively strong solvent often used in epoxy coatings.

Cementitious Coatings
A coating containing Portland cement as one of its components.

Centipoise
One hundredth of a poise which is a unit of measurement for viscosity. Water at room temperature has a viscosity of 1.0 Centipoise.

Chalking
The formation of a brittle powdery coating on the surface of a paint film generally caused by exposure to ultraviolet radiation resulting in a loss of gloss.

Checking
Cracks in the surface of a paint film.

Chemical Resistance
A measure of the sensitivity of a material to attack or corrosion by a chemical material.

Chipping
Small pieces of paint removed from the surface, typically a sign of physical damage.

Chips
Marble granules screened to various sizes used in thin-set terrazzo. The common sizes used in terrazzo are 0, #1, and #2. The term chips is also used to describe the colored quartz aggregate used in broadcast decorative flooring. See “Paint Chips.”

Chlorinated Hydrocarbon
A class of strong, fast evaporating, nonflammable solvents such as carbon tetrachloride, methylene chloride or trichloroethylene.

Chlorinated Rubber
A coating resin formed by the reaction of rubber with chlorine gas. Often used for chemical or water-resistant properties.

Citric Acid
Used for the etching of concrete, producing a low profile, useful when the concrete is to be coated with a system such as clear urethane

Clean and Dry
The requirement for Clean and Dry describes the condition of the surface prior to coating. The surface shall be clean, dry, and free of oil, grease, wax, form oils, and any other contaminant that may affect the adhesion of the coating. For best results and high performance requirements remove latencies and contaminants from pre-cast and cast-in-place concrete by abrasive blasting or high pressure water blasting. Dry means that the substrate contains less then 15% moisture. Concrete should be cured at least 28 days and mortar joints at least 15 days @ 75 F and 50% RH.

See also: ASTM D 4263 - 83; ASTM D 4258 - 83; ASTM D 4259 - 83; ASTM D 4260 - 83; ASTM D 4261 - 83; ASTM D 4662 - 83

Cleaners
A detergent, alkali, acid or similar contamination removing material, which is usually water borne

Cleaning and Etching
If the concrete is contaminated with oils or grease, the first step prior to any coating is to clean the surface with an alkali detergent cleaner and commercial degreaser (optimal removal is to use the detergent in combination with a steam cleaner)

Coal Tar
A dark brown to black bituminous material produced by the destructive distillation of coal.

Coal Tar Epoxy
A coating in which the binder or vehicle is a combination of coal tar and epoxy resins.

Coalescence
The formation of resinous or polymeric material when water evaporates from an emulsion or a latex system, permitting contact and fusion of adjacent particles; fusing or flowing together of liquid particles.

Coat
The material applied to a surface in a single application to form a film when dry.

Coating
The application of a layer of material onto the surface of a substrate.

Coating System
A number of coats separately applied, in a predetermined order, at suitable intervals to allow for drying and curing, resulting in a completed job.

Cobwebbing
Premature drying of a coating during spraying causing a spider web effect.

Cohesion
The forces which bind the particles of a coating together into a continuous film.

Color Fast
Nonfading.

Color Retention
The ability of a coating to retain its original color during weathering or chemical exposure.

Combustible Liquid
Any liquid having a flash point at or above 100 F (37.8 C).

Compatibility
The ability to mix with or adhere properly to other coatings without detriment.

Concrete Densifiers
Densifiers penetrate into concrete, and then chemically react with the calcium hydroxide within the surface of the concrete. This chemical interaction creates a by-product that fills and closes the pores in the concrete, thereby producing a denser surface.

Concrete Engraving
Concrete Engraving is staining the concrete to give it color, then engraving (routing) out a pattern. The routed area is now uncolored, having the appearance of a grout line.

Conductive Flooring
See “Static Control Floors”.

Conical Mandrel
An instrument used to evaluate a coating's resistance to cracking when bent over a specified radius.

Copolymer
Large molecules obtained by simultaneous polymerization of different monomers, as in vinyl copolymers.

Corrosion
The decay, oxidation or deterioration of a substance (steel, concrete, and others) due to interaction with the environment. See also "Rust"

Cove
A curved surface forming a junction between a floor and a wall, or a ceiling and a wall. When coated with polymers, the ‘finished’ cove provides a seamless, integral floor-to-wall/ wall-to-ceiling juncture.

Cove Paste
A high viscosity material that resists flowing on a vertical surface

Cracking
Splitting of a coating film, usually as a result of substrate movement or aging.

Crack Bridging
The formation of a coating over a depression

Craters
The formation of small bowl shape depressions in the coating film. Also, "Fisheyes." Most often caused by contaminants (oil, water, etc.) on the surface. May also be caused by applying coatings over an epoxy primer/coating that has an amine blush. (See “Blushing”).

Cross Rolling
Rolling the first pass of a coating application in one direction and the second at a right angle to the first, decreasing lap marks and providing a more even film distribution.

Cross Spraying
Spraying the first pass in one direction and the second at a right angle to the first, providing more even film distribution.

Crosslinking
The setting up of chemical links between molecular chains to form a three dimensional network of connected molecules. The chemistry of two component resin systems.

CSP/Concrete Surface Profile
ICRI has identified nine distinct profile configurations that replicate degrees of roughness considered to be suitable for the application of sealers, coatings, or polymer toppings. The recommended method for achieving each profile is as follows:

CSP 1 (Acid Etching), CSP 2 (Grinding), CSP 3 (Light Shotblast), CSP 4 (Light Scarification), CSP 5 (Medium Shotblast), CSP 6 (Medium Scarification), CSP 7 (Heavy Abrasive Blast), CSP 8 (Scabbling), CSP 9 (Heavy Scarification, Milling)

Cure Time
Time allotted for an applied coating film to reach a set stage of hardness (cure).

Curing Agent
A hardener or activator added to a synthetic resin to develop the proper film forming properties.

Curtains
Long horizontal runs in a coating film that occur on vertical surfaces when a coating is applied too heavily.

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D

Degreaser
A chemical solution or compound designed to remove grease, oils and similar contaminants.

Deionized Water
Water which has been purified to remove mineral salts.

Delamination
The separation between layers of coats due to very poor adhesion.

Density
Mass per unit volume, usually expressed as grams per milliliter or pounds per gallon.

Detergent Scrubbing
Chemical removal of oil, grease, and other deposits on concrete surfaces by scrubbing with a detergent solution. Detergent scrubbing is frequently used to prepare concrete for acid etching.

Dew Point
The temperature of a surface, at a given ambient temperature and relative humidity, at which condensation of moisture will occur.

DFT
Dry film thickness.

Diluent
A portion of the volatile components of a coating which is not a true solvent and has minimal affect on the viscosity.

Dispersion
The suspension of tiny particles, usually pigments, in a liquid, usually resin.

Dissipative Flooring System
See “Static Control Floors”.

Distilled Water
Water which has been purified by vaporizing the liquid and collecting the vapor which is then condensed back to a liquid having, in the process, removed the contaminants.

Drier
A chemical which promotes oxidation and subsequent drying of a paint film. Primarily used in oil base paints.

Dry Fall
A coating which is designed to dry rapidly so that the overspray can be easily removed from the surfaces below.

Dry Spray
Overspray or bounce back producing a sandy finish due to the sprayed particles having partially dried before reaching the surface.

Dry Time
Time allotted for an applied coating film to reach a set stage of cure or hardness.

Dry to Handle
The degree of cure at which a film will resist deformation due to handling.

Dry to Recoat
The time required for a cured film to dry prior to the application of a second coat.

Dry to Tack Free
A stage at which a coating film will form a skin to which dust will not adhere.

Dry to Touch
The state of dry at which a coating film will not transfer onto an item touched lightly against it.

Drying Oil
An oil having the property of hardening by oxidation to a tough film when exposed to air in the form a thin film.

Dulling
A loss of gloss or sheen.

Dyne
A centimeter-gram-second unit of force, equal to the force required to impart an acceleration of one centimeter per second per second to a mass of one gram.

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E

Effervescence
An effect in the film caused by rapid solvent release. This "boiling" of solvent causes a pinholed or cratered appearance reducing gloss.

Efflorescence
Water soluble salts, deposited as moisture evaporates, on the exterior of brick or concrete.

Elastic
The ability of a substance to return to its original shape or volume after a distorting force on the substance has been removed.

Elastomer:
A material which at room temperature can be stretched repeatedly to at least twice its original length and, upon immediate release of the stress, will return with force to its approximate original length

Elcometer
A trademark and brand name for a magnetic instrument for measuring dry film thickness of coatings applied to ferrous surfaces such as steel. Also an instrument for measuring the adhesion of coatings by the “Pull” method.

Electrical Equal- Potential Plane (EP)
A minute voltage produced by the separation of molecules into their ionic state.

Electrolyte
A substance that dissociates into ions in solution thereby becoming electrically conductive.

Electromotive Series
A listing of elements arranged according to their standard electrical potentials otherwise known as galvanic series.

Electrostatic Spray
The spray application of paint where the particles are charged causing them to be electrically attracted to the grounded surface.

Electrostatic Dissipative (ESD)
A conductive coating or topping that has a resistance of more than 1,000,000 ohms, but less than 10,000,000,000 ohms. See Conductive.

Emulsion
A two phase liquid system in which small droplets of one liquid are immiscible in and are dispersed uniformly throughout a second continuous liquid phase.

Enamel
A term used to characterize a coating that has a glossy smooth finish.

Epoxy
A synthetic resin derived from petroleum products that can be cured by a catalyst or used to upgrade other synthetic resins to form a harder, more chemical resistant film. Extremely tough and durable synthetic resin used in some coatings. Epoxy coatings are extremely tough, durable and highly resistant to chemicals, abrasion, moisture and alcohol.

Epoxy Elastomers
Where an ‘elastomer’ is any of various polymers having the elastic properties of natural rubber, an epoxy elastomer hybrid generally includes about 1:5 to 5:1 parts of epoxy to elastomer, and more preferably about 1:3 to 3:1 parts or epoxy to elastomer. The epoxy/elastomer hybrid, when added to a sealant material, preferably is added to modify structural properties of the sealant material such as strength, toughness, stiffness, flexural modulus, or the like. Additionally, the epoxy/elastomer hybrid may be selected to render the sealant material more compatible with coatings such as water-borne paint or primer system or other conventional coatings.

Terrazzo Epoxy
A two-part adhesive, employing epoxy resin, an epoxy hardener used for bonding marble or other stone chips set in Portland cement to a backup material. Used in areas that have heavy ‘pedestrian’ traffic, where aesthetics are an important consideration. Initial cost is high, but maintenance and life-cycle costs are favorable compared to other flooring options.

Ester
Compounds formed by the reaction of alcohols and organic acids.

Etching
The treatment of a surface with an acid in order to dissolve loose particles or provide a profile. See “Acid Etching.”

External Atomization
Using air to break up a coating material after it has exited the spray gun nozzle.

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F

Fading
Loss of gloss or sheen.

Fan Pattern
The geometry of a spray pattern.

Feather Edge
Reduced film thickness at the edge of a topping in order to produce a smooth, continuous appearance. It is recommended to key in edges of floor toppings.

Ferrous
An iron containing metal.

Filler
A compound used to extend or bulk a coating to provide extra body or hiding power.

Film
A layer of coating or paint.

Film Build
The dry film thickness characteristics of a coat.

Film Integrity
The continuity of a coating free of defects.

Film Thickness Gauge
A device for measuring wet or dry film thickness.

Fineness of Grind
The degree of dispersion of particles within a liquid.

Fingering
A broken spray pattern delivering heavier paint to one area than another.

Flammable
Any substance easily ignited in the presence of a flame; any liquid having a flash point below 100 F (37.8 C).

Flash Point
The lowest temperature of a liquid at which sufficient vapor is provided to form an ignitable mixture when mixed with air.

Flash-Off-Time
Time which must be allowed for any solvent to be released after the application of a coating to prevent bubbling in subsequent coats.

Flexibility
The degree at which a coating is able to conform to movement or deformation of its supporting surface without cracking or flaking.

Floating (Flooding)
A concentration of one of the ingredients of the pigmented portion of a coating at its surface giving rise to a color change.

Floor Blistering
Blisters are hollow, low-profile bumps on the concrete surface, typically from the size of a dime up to 1 inch, but occasionally even 2 or 3 inches in diameter. A dense troweled skin of mortar about 1/8 inch thick covers an underlying void that moves around under the surface during troweling. Blisters may occur shortly after the completion of the finishing operation.

Flow
The degree to which a wet coating can level out after application so as to eliminate brush marks and produce a smooth uniform finish.

Fluorescent
A class of pigments which, when exposed to visible light, emit light of a different wavelength producing a bright appearance.

Force Drying
The acceleration of drying by increasing the ambient temperature.

Fungicide
A substance poisonous to fungi which retards or kills mold and mildew growth

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G

Gelled
A coating which has thickened to a jelly like consistency making it unusable.

Generic
Belonging to a particular family.

Gloss
The sheen or ability to reflect light.

Gloss Retention
The ability to retain the original sheen during weathering.

Glossib
That property of the cured epoxy or any other material which causes it
to reflect light.

Glycol Ether
A group of relatively slow evaporating, strong solvents commonly utilized in epoxy coatings.

Grinding
A method of surface preparation. It is the rotation of one or more abrading stones or discs applied under pressure at right angles to the surface.

Grit
An abrasive blasting media obtained from slag and various other materials.

Grit Blasting
Abrasive blasting using grit as the blasting media.

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H

Hardener
An activator curing agent, catalyst or cross-linking agent.
A substance or mixture of substances added to an epoxy resin to
promote or control the curing reaction by taking part in it.

Hardness
The degree to which a material will withstand pressure without deformation or scratching.

Hiding
The ability of a coating to obscure the surface to which it is applied.

High Build
A term referring to a coating which can produce a thick film in a single coat.

High & Ultra High Pressure Water Jetting
Cleaning of concrete or steel surfaces by spraying water at pressures between 5,000 & 45,000 psi (35-300 MPa) to remove heavy encrustation of dirt and loose, friable material. This method can also remove some coatings. See low-pressure Water Cleaning.

Holiday
Any discontinuity, bare or thin spot in a painted area.

Hydrocarbon
Extracts from petroleum such as gasoline, lubricating oils, solvents, etc.

Hydrophilic
A substance which absorbs or has an affinity for water. (Water loving)

Hydrophobic
A substance which does not absorb or exhibit an affinity for water. (Water fearing)

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I

ICRI - International Concrete Repair Institute.
One of the best reference sources for the coatings industry, ICRI had its origin at a World of Concrete seminar in February of 1988.

The organizing members agreed on a statement of purpose, which is:

To improve the quality of concrete restoration, repair, and protection, through education of, and communication among, the members and those who use their services.

Immersion
Referring to an environment which is continuously submerged in a liquid.

Impact Resistance
The ability to resist deformation or cracking due to a forceful blow.

Incompatibility
Unsuitable for use together because of undesirable chemical or physical effects.

Induction Time
The period of time between mixing of two component products and the moment they can be used. Also known as “Sweat Time”.

Inert Pigment
A non-reactive pigment, filler or extender.

Inhibitive Pigment
A pigment which assists in the prevention of the corrosion process.

Inorganic
The designation of compounds that do not contain carbon.

Inorganic Zinc
A coating based on a silicate resin and pigmented with metallic zinc, which has excellent resistance to organic solvents and general weathering.

Intercoat Adhesion
The adhesion between successive coats of paint.

Intercoat Contamination
The presence of foreign matter such as dust or dirt between successive coats of paint.

Internal Mix
A spray gun in which the fluid and air are combined before leaving the gun.

Intumescent Coating
A fire retardant cooling which, when heated, produces nonflammable gasses which are trapped by the film, converting it to a foam, thereby insulating the substrate.

Ion
An atom or group of atoms possessing a positive or negative electric charge as a result of having lost or gained an electron.

Iron Oxide
An oxide of iron. Often used as a pigment source in coatings and toppings. The natural occurring state of steel.

Isopropyl Alcohol (IPA)
A volatile, flammable liquid used as a solvent commonly known as rubbing alcohol.

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K

Ketone
An organic compound with a carbonyl group attached to two carbon atoms. Usually indicates a strong, fast evaporating solvent.

Krebs Units (KU)
An arbitrary unit of viscosity for a Stormer viscosity instrument.

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L

Lacquer
A coating comprised of a synthetic film forming material, which is dissolved in organic solvents and dries by solvent evaporation.

Lacquer Thinner
Commonly used term used to describe a solvent blend of ethyl alcohol, ethyl acetate and toluene.

Laitance
An accumulation of fine particles, loosely bonded, on the surface of fresh concrete, caused by the upward movement of water. This laitance must be removed before applying a topping.

Latex
A stable dispersion of a polymer substance in an aqueous medium. A common term for water reducible coatings.

Lead-Free
Contains, by weight, less than 0.5% lead for industrial products and less than 0.6% lead in consumer products.

Leafing
The orientation of pigment flakes in a horizontal plane, usually aluminum, having leaf-like veins.

Lifting
Softening and raising or wrinkling of a previous coat by the application of an additional coat; often caused by coatings containing strong solvents. See Aligatoring.

Low-Pressure Water Cleaning
Cleaning of concrete or steel surfaces by spraying water at pressures less than 5,000-psi to remove dirt and loose, friable material. This method will not remove coatings or sealers. See High-Pressure Water Cleaning.

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M

Mandrel
A round metal bar or rod 25 mm (1 in.) in diameter and approximately 460 mm (18 in.) long. Used in ASTM testing for flexibility of materials.

Mastic
A term used to describe a heavy-bodied coating or binder resin.

Membrane
Flexible systems that provide skid-resistant wear surfaces on bridge decks, parking garages, and walkways.

Metalizing
A method of applying atomized, molten metal such as zinc and aluminum to a surface.

Methyl Ethyl Ketone (MEK)
A low boiling, highly volatile flammable solvent with extremely good solubility for most epoxies, urethanes and other coatings.

Methyl Isobutyl Ketone (MIBK)
A medium boiling solvent commonly used in coatings.

Methylmethacrylate
A fast setting polymer with strong odor, and sensitive to water that terminates the polymerization reaction

Micron
A micrometer or one millionth of a meter.

MIL
One one-thousandth of an inch; 0.0001 inches. Commonly used to denote coating thickness.

Mildew
A superficial growth of living organic matter produced by fungi in the presence of moisture; results in discoloration and decomposition of the surface.

Mill Scale
A layer of iron oxide formed on the surface of steel plates during hot rolling, bluish in appearance.

Mineral Spirits
A refined petroleum distillate having a low aromatic hydrocarbon content and low solubility, suitable for thinning of alkyd coatings.

Miscible
Capable of mixing or blending uniformly.

Mist Coat
A thin tack coat usually applied to fill porous surfaces such as zinc rich primers.

Moisture Vapor Emissions
The process by which moisture exits a concrete slab.

Moisture Vapor Transmission
The process by which moisture moves through a slab of concrete. This is impacted by temperature, humidity and vapor pressure.

Monomer
A substance of low molecular weight molecules capable of reacting to form longer molecules called polymers.

Mortar Systems
A means of protecting a concrete floor, and the choice for applications that have the greatest chemical resistance, thermal shock resistance and heavy duty traffic. This is also the system of choice to repair badly spalled, uneven, or sloped substrates.

Mottled
Spots of different tones and colors next to each other resulting in a blotchy effect on the coating film.

Mudcracking
A paint film defect characterized by a broken network of cracks in the film.

Muriatic Acid
Obsolete name for concentrated hydrochloric acid. Commonly diluted and used for etching concrete.

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N

NACE
National Association of Corrosion Engineers.

Neutral
A liquid which is neither acid nor alkali such as water (pH7).

Non-Drying Oil
An oil, which undergoes little or no oxidation when, exposed to air and therefore has no film forming properties.

Nonferrous
A term used to designate metals or alloys that do not contain iron. Example: brass, aluminum, and magnesium.

Nonflammable
A compound which does not burn in the presence of a flame.

Nonvolatile
The portion of the paint left after the solvent evaporates.

Novolac Epoxies
Provide an increase in chemical resistance over regular epoxies. This increase is about 30%. Epoxy chemical resistance to sulfuric acid, as example, increases from about immersion service at 70% concentration to immersion service at 98% concentration. Resistance to heat also increases.

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O

Oil Length
The ratio of oil to resin expressed as a percentage of oil by weight in the resin. Used to determine the physical properties of a resin.

Opacity
The ability of a paint film to obliterate or hide the color of the surface to which it is applied. See “Hiding”.

Orange Peel
The dimpled appearance of a dried paint film resembling the peel of an orange.

Organic
Designation of any chemical compound containing carbon.

Organic Zinc
A zinc rich coating utilizing an organic resin such as an epoxy.

Osmosis
The diffusion of liquid through a paint film or other such membrane.

Out-Gassing
Air can escape from porous concrete and be trapped in the coating surface.

Overspray
Sprayed coating that is dry when it hits the surface resulting in dusty, granular adhering particles, reducing gloss and presenting a poor appearance.

Oxidation
The formation of an oxide. The combining of oxygen with any compound.

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P

Paint
(Verb) To apply a thin layer of coating to a substrate by brush, roller, spray or other suitable method.

(Noun) A pigmented liquid designed for application to a substrate, in a thin layer, which is then converted to a solid film. Paint is designed to protect and/or decorate the surface it is applied to.

Paint Chips
Flaked vinyl paint chips used with epoxy and/or polyurethane resins to provide a relatively thin (1/32") decorative flooring.

Pass
The motion of a spray gun in one direction only.

Passivate
To make a surface such as steel inert or unreactive, usually by chemical means.

Paste
The product of a dispersion process. It is usually very high viscosity used for vertical applications, as in “Cove Paste”. Also a concentrated pigment dispersion used for shading. A high viscosity material that resists flowing on a vertical surface

Pattern
The shape or stream of material coming from a spray gun.

Peeling
A film of paint or coating lifting from the surface due to poor adhesion. Peeling normally applies to large pieces. (See chipping)

Perm
The time rate of water vapor migration through a material of one grain per hour, per square foot, per inch of mercury pressure difference.

Permeability
The degree to which a membrane or coating film will allow the passage or penetration of a liquid or gas. Adding flake to a coating enhances its permeability rating.

pH
A measure of acidity and alkalinity; pH 1-7 is acid and pH 7-14 is alkali. 7 is neutral.

Phenolic
A synthetic resin used for heat or water resistance.

Phosphatizing
A pretreatment of steel by a chemical solution containing metal phosphates and phosphoric acid to temporarily inhibit corrosion.

Pickling
The treatment of steel for the removal of rust and mill scale by immersion in a hot acid solution containing an inhibitor.

Pigment
A finely ground natural or synthetic, insoluble particle adding color and opacity or corrosion inhibition to a coating film.

Pigment / Binder Ratio
A ratio of total pigment to binder solids in paint.

Pigment Float
An epoxy coating is a chemical reaction, typically taking hours to reach completion. Pigment(s) are solid particles in suspension within a film that is cross-linking. If you touch an epoxy, well into the cure time, color can change, typically lighter as the process is disrupted. Special colors, dark/deep blues, browns and greens, are more likely to have pigment flotation issues.

Pigment Grind
The action of dispersing a pigment in a liquid vehicle.

Pigment Volume Concentration (PVC)
The percent by volume occupied by pigment in the dried film of paint generally expressed as a percentage.

Pinholing
A film defect characterized by small, pore-like flaws in a coating which extend entirely through the film.

Plasticizer
An agent added to the resin to aid in flexibility.

Poise
A centimeter-gram-second unit of dynamic viscosity equal to one dyne-second per square centimeter

Polyester Resin
A group of synthetic resins that contain repeating ester groups. A special type of modified alkyd resin.

Polymer
A substance of molecules that consist of one or more structural units repeated any number of times.

Polymerization
A chemical reaction in which two or more small molecules combine to form large molecules containing repeated structural units.

Polyureas
Fast-setting polymer exhibiting excellent elongation but generally with lower adhesion properties relative to epoxy.

Polyurethane
An exceptionally hard, wear resistant coating made by the reaction of polyols with a multi-functional isocyanate.

Polyvinyl Chloride (PVC)
A hard tough plastic solid used for plastics and coatings, commonly known as vinyl.

Porosity
The presence of numerous minute voids in a cured material.

Pot Life
The length of time a paint material is useful after its original package is opened or a catalyst or other curing agent is added.

Practical Coverage
The spreading rate of a coating calculated at the recommended dry film thickness and assuming 15% material loss.

Pressure Cleaning
Blast cleaning of metal or concrete using high velocity water.

See - High & Ultra High Pressure Water Jetting

Primer
The first coat of material applied to a surface, formulated to have good bonding, wetting and inhibiting properties.

Profile
The term used to describe the anchor pattern of a surface produced by sandblasting, acid etching or similar method.

Pull Test
A method of testing the effective adhesion of a topping or coating to a surface by gluing a button to the surface and slowly applying pull pressure until the coating comes loose or the surface breaks, resulting in a quantitative measurement in psi. See “Tape Test.”

Pyrometer
An instrument used to measure the temperature of a surface.

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Q

QUV
An accelerated testing device designed to evaluate the fading properties of a coating by exposure to high intensity, ultraviolet light.

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R

Reducer
Commonly known as thinner.

Reflectance
The ratio of the intensity of reflected light to that of incidental light.

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
A group of organic materials, either natural or synthetic, which can be molded or dissolved.

Rheology
The science characterizing fluid deformation or flow.

Roller
A cylinder covered with lamb's wool, felt, foamed plastics or other materials used for applying paint.

Runs
Sagging and curtaining of a coating or paint film, usually caused by improper thinning, excessive film build or poor application techniques.

Rust
The corrosion of steel or iron is an electrochemical phenomena wherein the base metal reverses to a lower, more stable energy state. If the corrosive environment is water or brine, then the corrosion product formed is commonly known as rust.

In the case of other chemicals, such as alkali's or acids, other combinations of iron salts are formed as part of the corrosion product. The electrochemical corrosion process may be retarded or stopped by the proper use of protective coatings.

One preventive method provides an insulation barrier between the corrosive environment and the metallic substrate. This type of protection is exemplified by the painting of structural steel with organic coatings such as epoxies, alkyds and acrylics. An even more effective method is to use a more reactive metal such as zinc. A conductive zinc-filled coating protects the metal by galvanic protection. The zinc sacrifices itself and corrodes in preference to the steel.

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S

Sag Resistance
The ability of a paint to be applied at proper film thickness' without sagging.

Sagging
The downward movement of a paint film on a vertical surface, between the time of application and drying, resulting in an uneven coating having a thick lower edge.

Salt Atmosphere
A moist, heavily laden air with a high chloride concentration; used as a test for accelerated corrosion evaluations and also present near seacoast areas.

Salt Fog Test
A cabinet designed to accelerate the corrosion process in evaluating coatings; combines 100% humidity with a 5% salt concentration at 100 F in an enclosed cabinet.

Saponification
The alkaline hydrolysis of fats whereby a soap is formed; typical reaction between alkyds and galvanized metals resulting in peeling.

Satin Finish
A descriptive term generally referenced to coatings with a 60-gloss reading between 10 and 40.

Scabblers
Air-powered units that use a number of small pneumatic hammers to pulverize the surface of concrete, providing an extremely rough profile for toppings and overlayments.

Scarifying
To ‘scratch’ the surface of concrete, using a rotating drum with hardened cutters. Scarifying can achieve a surface profile ranging from 60 grain sandpaper to 1/8-inch grooves.

Sealer
A coating used on absorbent surfaces prior to painting.

Seamless Epoxy Floors
Seamless floors are based upon a chemical reaction which converts the liquid applied flooring material into a strong and durable solid floor. This chemical reaction crosslinks the various components of the flooring system through a catalyzed or addition reaction forming covalent linkages.

Semi-Gloss - See "Satin Finish."

Settling
The sinking of pigments, extenders or other solid matter in a coating, on standing in a container, with a consequent accumulation on the bottom of the can.

Shade
A term employed to describe a particular hue or tone.

Shelf Life
The maximum time interval in which a material may be kept in a usable condition during storage.

Shop Primer
An inexpensive, rust-inhibiting primer designed to protect steel from general weathering immediately after fabrication and before final coating.

Shot Blasting
Abrasive blasting with round iron shot, or any material which retains its spherical shape, for peening purposes. See “Vacuum Blasting”.

Shot-blasting Machine
Machine using centrifugally-thrown shot to clean surfaces.

Silica Sand
Clean sand made up of sharp silica particles, not containing dirt or clay, used for abrasive blast cleaning and as a filler in many topping systems.

Silicone Resins
Resins based on silicone instead of carbon, generally used for their outstanding heat resistance and water repellence. Old silicone resin coatings generally must be removed before applying a new coating.

Skid Inhibition
Critical in areas of wet service. The size and type of applied aggregate dictates the aggressiveness of the skid resistance of any system. Cleanability is inversely proportional to the amount of skid resistance.

Skinning
The formation of a solid membrane on the top of a liquid, caused by partial curing or drying of the coating during storage.

Slurry
A thin mixture of a liquid, especially water, and any of several finely divided substances, such as cement.

Slurry System
One means of protecting a concrete floor. A slurry system provides a thickness between 1/16 and 1/8 of an inch that holds up to most wheeled traffic and provides greater durability. Incorporating an aggregate in the slurry imparts long-lasting skid inhibition.

Solids by Volume
The percentage of the total volume occupied by nonvolatile compounds.

Solvent
A liquid in which another substance may be dissolved.

Solvent Entrapment
The encapsulation of solvent within a cured coating film due to improper drying conditions; results in a soft film.

Sound Rusted Substrate
A rusted substrate cleaned of all loose rust and other loose materials, but not cleaned to bare metal.

Spalled Concrete
Concrete broken into chips, fragments, or flakes.

Specification
A set of instructions detailing the plan for coating of a project; a list of criteria for a coating.

Spray Head
The combination of needle, tip and air cap.

Spray Pattern
The configuration of coating sprayed on the surface.

Spread Rate
Coverage, usually at the specified dry film thickness.

Squeegee
A T-shaped implement having a crosspiece edged with rubber, used to remove water from a surface or to apply a coating to a surface

SSPC
Formerly the Steel Structures Painting Council, now the Society for Protective Coatings for more information about SSPC visit their WEB site at www.SSPC.org.

SSPC-SP 1
Covers the requirements for the solvent cleaning of steel surfaces.

A method for removing all visible oil, grease, soil, drawing and cutting compounds, and other soluble contaminants from steel surfaces.

Intended for use prior to the application of paint and in conjunction with surface preparation methods specified for the removal of rust, mill of rust, mill scale or paint.

SSPC-SP 2
Covers the requirements for the hand tool cleaning of steel surfaces.

A method of cleaning steel surfaces by the use of non-power hand tools.

Removes all loose mill scale, loose rust, loose paint, and other loose detrimental foreign matter . It is not intended that adherent mill scale, rust, and paint be removed by this. Mill scale, rust, and paint are considered adherent if they cannot be removed by lifting with a dull putty knife.

ISO 8501-1:1988 or other usual standards may be used to further define the surface, if agreed upon by all parties involved.

SSPC-SP 3
Covers the requirements for the power tool cleaning of steel surfaces. A method of preparing steel surfaces by the use of power assisted hand tools.

Removes all loose mill scale, loose rust, loose paint, and other loose detrimental foreign matter, it is not intended that adherent mill scale, rust, and paint be removed by this process. Mill scale, rust, and paint are considered adherent if they cannot be removed by lifting with a dull putty knife.

IS0 8501-1:1988 or other visual standards of surface preparation agreed upon by the contracting parties may be used to further define the surface.

SSPC-SP 5
Covers the requirements for white metal blast cleaning of steel surfaces by the use of abrasives.

When viewed without magnification the surface shall be free of all visible oil, grease, dirt, dust, mill scale, rust, paint, oxides, corrosion products, and other foreign matter.

Acceptable variations in appearance that do not affect surface cleanliness include variation caused by the type of steel, original surface condition, thickness of the steel, weld metal, mill or fabrication marks, heat treating, heat affected zones, blasting abrasive, and differences in the blast pattern.

SSPC-VIS 1-89 or other visual standards of surface preparation may be specified to supplement the written definition.

SSPC-SP 6
Covers the requirements for commercial blast cleaning of steel surfaces by the use of abrasives.

When viewed without magnification the surface shall be free of all visible oil, grease, dirt, dust, mill scale, rust, paint, oxides, corrosion products and other foreign matter, except for staining as noted below.

Staining shall be limited to no more than 33% of each square inch of surface area and may consist of light shadows, slight streaks or minor discoloration's caused by stains of rust, stains of mill scale, or stains of previously applied paint. Slight residues of rust and paint may also be left in the bottoms of pits, if the original surface was pitted.

SSPC-VIS 1-89 may be used to supplement this written spec.

SSPC-SP 7
Covers the requirements for brush-off blast cleaning of steel surfaces by the use of abrasives.

When viewed without magnification the surface shall be free of all visible oil, grease, dirt, dust, loose mill scale, loose rust, and loose paint. Tightly adherent mill scale, rust and paint may remain on the surface. Mill scale, rust and paint are considered adherent if they cannot be removed by lifting with a dull putty knife.

The entire surface shall be subjected to the abrasive blast. The remaining mill scale, rust or paint shall be tight.

SSPC-VIS 1-89 may be used to supplement the written spec.

SSPC-SP 8
Covers the requirements for the pickling of steel surfaces.

A method of preparing steel surfaces by chemical reaction, electrolysis, or both. The surfaces when viewed without magnification shall be free of all visible mill scale and rust.

SSPC-SP 10
Covers the requirements for near-white blast cleaning of steel surfaces by the use of abrasives.

Near-white blasted surfaces, when viewed without magnification, shall be free of all visible oil, grease, dirt, mill scale, rust, paint, oxides, corrosion products, and other foreign matter, except for staining as noted below.

Staining shall be limited to no more than 5% of each square inch of surface area and may consist of light shadows, slight streaks, or minor discoloration's caused by stains of rust, stains of mill scale, or stains of previously applied paint.

SSPC-SP 11
Covers the requirements for power tool cleaning to produce a bare metal surface and to retain or produce a surface profile. (1 mil minimum) Suitable where a roughened, clean, bare metal surface is required, but where abrasive blasting is not feasible or permissible.

Differs from SSPC-SP 3 in that SP 3 requires only the removal of loosely adherent materials and does not require producing or retaining a surface profile.

Surfaces prepared per this spec, when viewed without magnification, shall be free of all visible oil, grease, dirt, dust, mill scale, rust, paint, oxide, corrosion products, and other foreign matter slight residues of rust and paint may be left in the lower portions of pits if the original surface is pitted.

Static Control Floors
Defined as a flooring system that can drain and/or dissipate static charges by grounding personnel, equipment or other objects contacting the floor surface or that controls the generation and accumulation of static charges. The resistance to the movement of electrons across the material’s surfaces defines static control floorings into two categories:

  1. Conductive Floor has a resistance of 2.5 x 104-106 ohms per 3 feet. It can drain static charge dissipating a 5,000 volt charge to zero in 0.05 seconds. A conductive floor material, because it has low electrical resistance, allows electrons to flow easily across its surface or through its volume. If a charged conductive floor is grounded, or coupled to another conductive object that is grounded, the charge accumulated on the floor will be uniformly distributed throughout the floor and rapidly dissipated to ground. Conductive flooring prevents the build-up of a static charge, eliminating the potential of an ESD event.

  2. Static Dissipative Floor has a resistance of 106-109 ohms per 3 feet. It adds no static electricity to the environment and drains off a 5,000 volt charge to zero in less that 0.2 seconds.

Stoichiometery
The determination of the relative quantities of the substances concerned in any chemical reaction; as mix ratio.

Stress Corrosion Cracking
Spontaneous cracking produced by the combined action of corrosion and static stress.

Strong Solvent
Any solvent capable of dissolving large quantities of a specified subject.

Substrate
The surface to be painted.

Surface Profile
The result of a mechanical etch or profile, miniature ridges and valleys give concrete the “tooth” required to form a successful bond. Without this “profiling” as a base, the chances of coatings becoming chipped or breaking up altogether increase significantly, and the life expectancy of the floor is reduced.

Surfacer
Pigmented composition for filling depressions in order to obtain a smooth, uniform surface before applying the finish coat.

Surface Tension
The property of a liquid which causes the surface to pull into the smallest area for a maximum volume, hence, drops are spherical. The fact that water drops on a wax surface do not spread out due to surface tension. If a wetting agent were to be added to the water the round droplet would spread out into a film because of the lowered surface tension

Surfactant
An additive, which reduces surface tension thereby improving wetting or helping to disperse, pigments or inhibit foam.

Suspension
A relatively coarse, non-colloidal dispersion of solid particles in a liquid.

Synthetic
Manufactured, as opposed to naturally occurring.

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T

Taber Abraser
An instrument used to measure abrasion resistance.

Tails
Finger-like spray pattern produced by improper gun or coating material adjustment.

Tape Test
A non-quantitative method of testing for adhesion whereby tape is applied to the coated surface and then removed to see if the coating comes off with it. See "Pull Test."

Tape Time
The drying time of a coating required prior to masking sections for lettering or striping after which tape will not distort the finish.

Thermocouple
A temperature measuring device.

Thermoplastic
Resins having the property of becoming soft upon the application of heat but which regain hardness after cooling.

Thermosetting
Resins having the property of becoming insoluble or hard upon the application of heat.

Thinners
A liquid (solvent) added to a coating to adjust viscosity.

Thixotropic
An adjective which describes full bodied material that undergoes a reduction in viscosity when shaken, stirred or otherwise mechanically disturbed but readily recovers its original full bodied condition upon standing.

Toluene
An aromatic solvent with a high boiling range and low flash point classified as a strong solvent.

Tooth
The profile, mechanical anchor pattern or surface roughness.

Toppings
Decorative flatwork can be enhanced by installing an epoxy overlay on the surface. Critical in this process is good surface preparation and achieving a good bond. This process can make existing concrete more durable and appealing.

Two-Pack
A coating that is supplied in two parts and must be mixed in the correct proportions before use in order to cure.

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U

Undercoat
The coat applied to the surface after preparation and before the application of a finish coat.

Underfilm Corrosion
Corrosion that occurs under films in the form of randomly distributed hairlines.

Urethane
An important resin in the coatings industry. A true urethane coating is a two-component product that cures when an isocyanate (the catalyst) prompts a chemical reaction that unites the components
UV Exposure
Sunlight or other artificial ultraviolet light will turn epoxy floors amber. A two-component acrylic urethane floor typically offers the best resistance to UV light and when part of a broadcast system with decorative aggregates discoloration is minimized because the broadcast material leaves only a small amount of epoxy resin on the surface.

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V

Vacuum Blasting
A shot blasting apparatus that has a vacuum attachment that removes the dust and debris during the blasting operation. This is the preferred surface preparation method. See “Shot Blast”

Vapor Barrier
See Vapor Retarder

Vapor Retarder
A material that impedes the transmission of water vapor under specified conditions.

Vapor Transmission Rate
The rate at which moisture passes through a material or coating. See "Moisture Vapor Test"

Vehicle
The liquid portion of a paint in which the pigment is dispersed. Comprised of binder and thinner.

Vinyl Copolymer
A resin produced by copolymerizing vinyl acetate and vinyl chloride.

Vinyl Esters
A fast-setting polymer sensitive to moisture and having a pungent odor.

Viscometer
One of several types of instruments for measuring a liquid’s viscosity.

Viscosity
A measure of fluidity of a liquid.

Viscosity Cup
An efflux viscometer utilizing a measured volume of liquid flowing through a precise orifice.

Voids
Holidays, holes or skips in a coating.

Volatile Content
The percentage of materials which evaporate from a coating.

Volatile Organic Compounds (VOC)
A measure of the total amount of organic compounds evaporating from a coating film, excluding water.

Volume Solids
The volume of the nonvolatile portion of a composition divided by the total volume expressed as a percent used to calculate coverage rate.

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W

Walnut Shell
Black walnut shells crushed to provide a hard non-mineral aggregate. Used in conductive troweled systems because of its non-sparking ability.

Wash Primer
A thin paint, usually a chromate, designed to promote adhesion or to be used as a barrier coat.

Water Blasting
Blast cleaning of metal or concrete using high velocity water. See Also “Pressure cleaning,” “Low-Pressure Water Cleaning,” & “High Pressure Cleaning.”

Water Spotting
A surface defect caused by water droplets depositing a circular ring of contaminants.

Water Vapor Permeability
A property of material which is water vapor permeance though unit thickness. Since materials that provide resistance to vapor flow are never used in unit thickness, the preferred evaluation of both materials and constructions is the permeance.

Water Vapor Permeance
The time rate of water vapor flow through unit area of the known thickness of a flat material or a construction normal to two specific parallel surfaces induced by unit vapor pressure difference between the two surfaces under specific temperature and humidity conditions. See perm.

Weatherometer
A machine designed for the accelerated testing of coatings.

Weld Slag
Amorphous deposit formed during welding.

Weld Splatter
Beads of metal left adjoining the weld.

Wet Abrasive Blasting
Compressed air blasting systems that incorporate water into the blast stream.

Wet on Wet Application
"wet on wet" means that the coating is applied in TWO separate coats or applications. Whenever possible contrasting colors should be utilized for the two coats to aid in the application.

Typically the structure is coated with the first coat and the applicator then turns around and begins the second application. The complete structure has the first coat applied before the second coat begins. Depending upon what is being coated the time between coats will vary dramatically. The key to the whole concept is that it is two independent coats. By applying the coating in two distinctive coats or applications, problems with pinholes, light millage areas, and solvent entrapment are minimized.

Wet Sandblasting
The incorporation of water into the sandblasting operation in order to minimize dust.

Wetting
The ability of a vehicle to flow onto the surface in order to achieve a good bond.

White Rust
The oxide of zinc formed on galvanized metal.

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X

Xylene (Xylol)
A flammable aromatic hydrocarbon solvent used in epoxies and fast drying alkyds

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Z

Zinc Dust
Finely divided zinc metal used as a pigment in protective coatings.

Zinc Phospho Oxide
A rust inhibitive pigment.

Zinc Rich Primer
An anti-corrosion primer for iron and steel incorporating zinc dust in a concentration sufficient to provide cathodic protection.

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