Auto glass replacement from A to Z

A pillar: A support for the vehicle’s roof located on either side of the vehicle at the very front. The sides of the windshield are bonded to the A pillar.

Accelerated aging: A set of laboratory conditions designed to produce, in a short time, the results of normal aging. Usual factors include temperature, light, oxygen and water.

Acetone: A colorless, volatile, water-soluble, flammable liquid made from either alcohol or by bacterial fermentation of carbohydrates; used in paints and varnishes as a general solvent and in chemical manufacturing.

Acute area: The area of the windshield directly in front of the driver’s eyes, beginning just above the steering wheel. It measures approximately 8 inches high and 11 inches wide and is used as the standard for the driver’s critical vision area by most auto glass shops and insurance companies in the United States.

Adhesion: The clinging or sticking together of two surfaces. The ability of an adhesive to stick to a surface.

Adhesive: Any substance capable of bonding other substances together by surface attachment. In an auto glass replacement context, it is a high-strength polyurethane material, unless otherwise specified.

Adhesive failure: failure indicated by the material’s failing, or pulling loose at the surface of the substrate. This is similar to Scotch tape peeling off a plastic substrate. 

Aerodynamics: The branch of physics that deals with the motion of a solid body through air and gases.

AGR: Abbreviation for auto glass replacement.

AGRSS: The Auto Glass Replacement Safety Standards Council, an organization that developed the American National Standards Institute standard recognized by the AGR industry.

Anneal: The controlled process for making glass strong and less brittle by heating and then cooling.

Antenna: A conductor that sends or receives electromagnetic waves, consisting commonly of a wire or set of wires. In some late-model vehicles, the radio antenna is incorporated into the windshield or back glass.

Anti-lacerative glass: Glass that has a resilient layer of polyvinyl butyral added to the inner surface. It prevents passengers from coming into contact with broken glass edges on the inner surface in the event of a collision.

Auto glass repair: A process that removes air from a break in laminated glass and fills it with a curable, optically matched resin. Synonymous with windshield repair.

Bead: A sealant or adhesive compound after application in a joint, irrespective of the method of application, such as a urethane bead applied to a pinchweld. A bead looks like a ribbon of adhesive rather than a round drop.

B pillar: A support for the roof located on either side of the vehicle, directly behind the front seat.

Bezel: A curved, tapered, decorative cover located behind the door latch or in the well of a door pull.

Belt molding: A rubber molding between the inner and outer panels of a vehicle door through which the door glass is raised and lowered.

Bond: The attachment at an interface between substrate and adhesive or sealant.

Bullet-resistant glass: Glass that consists of multiple layers of laminated glass. It is designed to resist penetration from medium- to super-powered small arms and high-powered rifles.

C pillar: A support for the roof located on either side of the vehicle, directly behind the rear seat. The sides of the back glass can be bonded to the C pillar.

Chemical cure: Curing by chemical reaction. This usually involves the cross-linking of a polymer.

Chip: Damage to the surface of the glass not associated with other types of damage.

Clip: Device that holds decorative chrome or moldings to the vehicle body. 

Close-cut or partial-cut installation: An installation method in which most of the existing adhesive-bead bed is left adhered to the metal frame and a small, fresh bead of adhesive is added to set the glass. Some vehicle manufacturers do not recommend this procedure.

Coated glass: Glass with a chemical film applied to one surface. The film can provide enhanced performance characteristics such as privacy, solar or mirror effects.

Cohesion: The ability of a sealant or adhesive to hold itself together. The internal strength of an adhesive or sealant.

Contaminant: A liquid or solid substance present in a break that must be removed before beginning repair.

Corrosion: The chemical reaction of air, moisture or corrosive materials on a surface; also called oxidation. The process of wearing away the surface of a solid.

Cosmetic blemish: A defect in the appearance of a vehicle. Includes torn upholstery, scratched paint and resin spills.

Cosmetic surface: A surface finished or decorated to improve its appearance; includes paint, glass and upholstery.

Cowl: A drain located above the firewall where the windshield wipers deposit rain water.

Cowl panel: A decorative, porous cover mounted to the cowl that covers the lower edge of the windshield. 

CSR: Abbreviation for customer service representative. Often a title for a dispatcher, bookkeeper or receptionist.

Cure: The hardening of a liquid material or adhesive by means of a chemical reaction.

Cure time: The time required for a chemical or other material to dry or set at a given temperature and humidity. Cure times vary with the type of material used and the thickness of the application. 

Damage: A break in laminated glass.

De-lamination: The failure of the bond between layers, as when windshield glass separates from the laminate, or when paint peels from the substrate.

Ding: Non-technical term used to refer to damage on laminated glass.

Division bar: A vertical run channel located between the door window and vent glass.

Doorframe: A vehicle part containing an exterior and interior panel that houses the door window and the mechanism used to operate that window.

Door panel: A decorative panel used to cover the interior panel of the doorframe.

Drag coefficient: The mathematical expression of the retarding force air exerts upon a body.

Dry fit: Process in which a technician sets the glass in the vehicle glass opening before applying adhesive or primer. The process is used to position the glass and mark the position with alignment markings or tape.

Drilling: The use of a drill to gain access to a tight break.
 
Elasticity: The ability of a material to return to its original shape after removal of a load.

Electro-chromatic mirror: An interior rearview mirror that senses the glare in oncoming light and automatically dims the vehicle’s high-beam headlights.

Edge crack: Any crack on the windshield that extends to an edge.

Encapsulated glass: A type of auto glass fabrication. Preassembled parts that contain hardware: moldings, fasteners, clips or gaskets. Glass with a decorative molding around all or part of the perimeter. The encapsulation also can act as a channel guide. The molding—encapsulation—is actually part of the glass and can be removed only by cutting it off the glass. 

Fast-cure urethane: An adhesive that cures faster than normal. The surrounding temperature and humidity determine the actual rate.

Fastener: An item that attaches one item to another such as a screw, bolt or rivet.

Federal Motor Vehicle Safety Standards: A series of standards required of automobile manufacturers by the federal government. All new vehicle models must meet these standards before they are allowed to be sold in the United States.

Flammable: A volatile liquid or gas that has a flash point of 100 degrees Fahrenheit or 38 degrees Celsius.

Flexing: A method of gaining access to a tight break by flexing the glass back and forth, either with a tool or by hand.

Floating crack: Any crack on the windshield that does not extend to an edge.

Flowering: A flower-petal effect around the outer edge of a repair. This is caused by the laminate detaching from the outer layer of glass.

Frit: The painted band around the perimeter of auto glass parts.

Full-strip installation: A process in which a technician removes the existing adhesive-bead bed from the vehicle and applies a fresh adhesive. 

Garnish moldings: The interior decorative moldings around the perimeter of glass parts.

Gasket: A seal, usually of rubber, that holds a piece of auto glass to the vehicle body. There are various sizes and shapes of glass-part gaskets, depending on vehicle design.

Heated urethane: A type of adhesive heated to a prescribed temperature before application. Heat pre-cures the adhesive for faster setting.

Idler guide: Device used to secure moveable windows.

Impact: Most common break. It occurs when an object hits the windshield.

Impact point: Actual location on the glass that was struck by an object—usually a stone—resulting in damage.

Infrared: Part of the light spectrum. Infrared rays that cause heat.

Laminate: Vinyl inner layer of laminated glass.

Laminated glass: A type of safety glass that has a layer of plastic bonded between layers of glass. Laminated glass is used mainly for windshields, but can now be found in door glass parts as well.

Lap-shear strength: Strength demonstrated by the diagonal pull of two substrates until adhesive failure. The name comes from the lap joint created by the test samples and the shear action used to pull the samples apart.

Legs: Short cracks that emanate from a break.

Linkage: A mechanism used to operate door latches and door locks.

Lite: A term for a pane or finished piece of glass.

Locator tapes: Tape used to align the glass to the vehicle body during a dry fit.

Long crack: A crack on the windshield of more than  6 inches.

Mobile unit: A vehicle, usually a van or light truck, properly equipped with repair and safety equipment and tools, driven to an auto glass repair customer’s home or place of business. Glass repairs are made from the vehicle.

NAGS: National Auto Glass Specifications or NAGS International, a subsidiary of Mitchell International in San Diego. Since 1927, NAGS has developed and issued part numbers that can be easily understood and are linked to specific glass parts rather than to specific vehicles. Details available from: NAGS, 9889 Willow Creek Road, San Diego, Calif. 92131-1119; 800/551-4012; fax, 619/653-5447; nags@ccmail.mitchell. com; www.nags.com.

NGA: National Glass Association, a national trade association that represents companies involved in auto glass installation and repair and architectural glasswork. Details available from: NGA, 8200 Greensboro Drive, Suite 302, McLean, Va. 22102; 703/442-4890; fax, 703/442-0630; nga@glass.org, www.glass.org.

NWRA: National Windshield Repair Association, a trade association for windshield repair professionals. Details available from: NWRA, 1251 Eisenhower Blvd., Harrisburg, Pa. 17111; 717/985-1501; fax, 717-985-1502; nwra@netrax.net; www.netrax.net/~NWRA.

OEM: Abbreviation for original equipment manufacturer.

OSHA: The Occupational Safety & Health Administration monitors workplace safety for the U.S. Department of Labor and issues guidelines for preventing violations. Details are available from: 200 Constitution Ave., Washington, D.C. 20210; 202/693-1999; www.osha.gov/.

Personal protective equipment: Safety gear worn by an auto glass repair technician. It includes Nitrile gloves, safety or ultraviolet glasses, a dust and mist mask with dual straps, a first-aid kit and any additional equipment required by company policy.

Pit: Impact point from which a small piece of glass is missing.

Plasticizer: A material that softens a sealant or adhesive by solvent action.

Polymer: A compound consisting of long chain-like molecules. The building units in the chain are monomers.

Polyvinyl butyral: Vinyl inner layer of laminated glass. Abbreviated PVB.

Quarter glass: Backside windows in a vehicle.

Regulator: A manually or power-operated device that rolls the vehicle’s windows up and down.

Resin: A solid organic material, generally not soluble in water, that has little or no tendency to crystallize. Resin is optically matched to auto glass and used to fill breaks and cracks.

Retainer: An item that holds steady a panel to a frame.

Reveal molding: Chrome or plastic molding that fits over and covers the exterior edges of the windshield and back glass.

Safety glass: A general term for laminated or tempered glass. Only laminated glass, however, can specifically be called laminated safety glass.

Shaded glass: Laminated glass with a dark color added to the top section of the inner vinyl layer to improve drivers’ visibility in glare. The color typically becomes lighter as the tint travels down the glass.

Shard: A sharp piece or fragment of glass.

Shelf life: The amount of time resin stays fresh without being used. If the material exceeds its shelf life, the resin might become unstable and unusable.

Short crack: A crack on the windshield of 6 inches or less.

Solar glass: Glass that either reflects or absorbs the ultraviolet and infrared rays from the sun.

Solvent: A liquid in which another substance can be dissolved.

Stone break: Non-technical term for damage on laminated glass.

Stress crack: Any crack that extends from an edge and lacks an impact point.

Substrate: A hard surface, glass or metal, with a sealant or adhesive bonded to it.

Tempered glass: A strong break-resistant type of safety glass that, if broken, shatters into small granular pieces.

Tinted glass: Glass with a small amount of color added.

Toxic: Poisonous or dangerous to humans if swallowed or inhaled, or by contact, possibly resulting in eye or skin irritation.

Translucent: Permitting light to come through but diffusing it so that objects on the other side appear vague, distorted or imperfect.

Transparent: Permitting light to come through without distortions so that objects on the other side can be seen clearly.

Twist: A crack occurring when the windshield is twisted, either by flexing in the vehicle frame or when mounted improperly. It worsens if the windshield has a nick in the edge.

U-channel molding: A molding that allows water to be channeled up and over the vehicle instead of around the A pillar.

Ultraviolet light: Part of the light spectrum. Ultraviolet rays can cause chemical changes in rubbery materials and polymers.

Vertical run guide: A weatherstrip or channel that steers the door glass in the frame when the glass is raised or lowered.

Viscosity: The thickness of a liquid material. A measure of the flow properties of a liquid or paste. Example: Honey is more viscous than water. Water, the standard of comparison, has a viscosity of 1⁄100 of a poise. Viscosity is tested by forcing the material through a determined hole and measuring the time it takes to flow.

V-bead: Sealant or adhesive compound applied in a triangular shape to a surface.

Weatherstrip: An item made of rubber or foam that insulates one space from another.

Windshield repair: A process that removes air from a break in laminated glass and fills the break with a curable, optically matched resin. Same as auto glass repair.

Wiring harness: A number of wires bundled together, with a common connector, to provide electrical power to various devices.

Wraparound molding: A molding with a U-shaped channel that is attached to the edge of the glass by means of pressure fit or adhesive.