A set of laboratory conditions designed to produce in a short time the results of normal aging. Usual factors included are temperature, light, oxygen, and water.
The clinging or sticking together of two surfaces. The state in which two surfaces are held together by forces at the interface.
Adhesion due to the physical interlocking of the adhesive with the surface irregularities of the substrate.
Type of failure characterized by pulling the adhesive or sealant loose from the adherend.
The progressive change in the chemical and physical properties of a sealant or adhesive.
Cracking of a surface into segments so that it resembles the hide of an alligator.
A compressible material used at the base of a joint opening to provide the proper shape factor in a sealant.
A sealant or compound after application in a joint irrespective of the method of application, such as caulking bead, glazing bead, etc. Also a molding or stop used to hold glass or panels in position.
Bed or Bedding
The bead of compound applied between light of glass or panel and the stationary stop or sight bar of the sash or frame, and usually the first bead of compound to be applied when setting glass or panels.
Amount of overlap between the stop and the panel or light.
A small piece of neoprene or other suitable material used to position the glass in the frame.
The attachment at an interface between substrate and adhesive, or sealant.
Thin layer of material used to prevent the sealant from bonding to the bottom of the joint.
The force per unit area necessary to rupture a bond.
A joint in which the structural units are joined to place the adhesive or sealant into tension or compression.
Application of putty or sealant compound to the flat surface of some member before placing the member in position, such as the buttering of a removable stop before fastening the stop in place.
A copolymer of isobutene and isoprene. As a sealant it has low recovery and slow cure, but good tensile strength and elongation.
Substance added in small quantities to promote a reaction, while remaining unchanged itself.
A sealant with a relatively low (less than 20%) movement capability.
To fill the joints in a building with a sealant.
Formation of a powdery surface due to weathering.
A three-sided, U-shaped opening in sash or frame to receive light or panel, as with sash or frame units in which the light or panel is retained by a removable stop. Contrasted to a rabbet, which is a two-sided L-shaped opening, as with face glazed window sash.
The measurement from the bottom of the channel to the top of the stop, or measurement from sight line to base of channel.
The sealing of the joints around lights or panels set in a U-shaped channel employing removable stops.
On rabbeted sash without stops, the triangular bead of compound applied with a glazing knife after bedding, setting, and clipping the light in place.
Failure of a material due to rapid cyclic deformation.
Finely ground material added to a sealant or adhesive to change or improve certain properties.
Strips, usually of sheet metal, to waterproof the junctions of building surfaces, such as roof peaks and valley, and the junction of a roof and chimney.
Pre-formed shapes, such as strips, grommets, etc., of rubber or rubberlike composition, used to fill and seal a joint or opening either alone or in conjunction with a supplemental application of a sealant.
A material composed of single molecules. A building block in the manufacture of polymers.
External structural member in curtain wall building. Usually vertical. May be placed between two opaque panels, between two window frames, or between a panel and a window frame.
Descriptive of a compound that does not form a surface skin after application.
Time interval between when an adhesive is applied and when it becomes no longer workable.
Formation of an oxide. Also the deterioration of rubbery materials due to the action of oxygen or ozone.
A reactive form of oxygen. A powerful oxidizing agent, it occurs naturally in the atmosphere.
A test of an adhesive or sealant using one rigid and one flexible substrate. The flexible material is folded back (usually 180°) and the substrates are peeled apart. Strength is measured in pounds per inch of width.
The amount of deformation which remains in a sealant or adhesive after removal of a load.
A material which softens a sealant or adhesive by solvent action.
The cgs unit of viscosity. Example: A polysulfide highway joint sealant might have a viscosity of 500 poises, at 77°F. Higher numbers indicate a more viscous material.
A compound consisting of long chain-like molecules. The building units in the chain are monomers.
Synthetic polymer usually obtained from sodium polysulfide. The polymer segments are generally terminated with -SH groups. Polysulfide rubbers make very good sealants.
A sealant which is preshaped by the manufacture before being shipped to the job site.
Pressure Sensitive Adhesive
Adhesive which retains tack after release of the solvent, so that it can be bonded by simple hand pressure.
A preparatory material which is applied to joint faces in order to improve adhesion.
A two-sided L-shaped recess in sash or frame to receive lights or panels. When no stop or molding is added, such rabbets are face glazed. Addition of a removable stop produces a three-sided U-shaped channel.
The framed opening ready to receive a pre-glazed sash or panel.
Reinforcement (in rubbers)
Increase of modulus, toughness, tensile strength, and so forth, by the addition of selected fillers.
A measure of energy stored and recovered during a loading cycle. It is expressed in percent.
A synthetic rubber based on silicone, carbon, oxygen and hydrogen. Silicone rubbers are widely used as sealants and coatings.
Imaginary line around the perimeter of a glazed glass product defined by the top edge of stationary and removable stops, or the line where the glazing sealant or gasket contacts the glass.
Liquid in which another substance can be dissolved.
Small blocks of composition, neoprene, etc., placed on each side of lights or panels to center them in the channel and maintain uniform width of sealant beads. Prevent excessive sealant distortion.
Spacer Shims “L” Shape
Devices that are “L” shaped in cross section and an inch or more in length, placed on the edges of lights or panels to serve both as shims to keep the lights or panels centered in the sash or frames, and as spacers to keep the lights or panels centered in the sash or frames, and as spacers to keep the lights or panels centered in the channels and maintain uniform width of sealant beads.
The panel on a curtain wall which covers the area between floors.
Same as spandrel except made of opaque glass.
The permanent stop or lip of a rabbet on the side away from the side on which lights or panels are set.
Either the stationary lip at the back of a rabbet, or the removable molding at the front of the rabbet, either or both serving to hold light or panel in sash or frame, with the help of spacers.
An adherend. The surface to which a sealant or adhesive is bonded.
The stickiness of the surface of a sealant or adhesive.
The load required to tear apart a sealant specimen. ASTM test method D-624 expresses tear strength in pounds.
Resistance of a material to a tensile force (a stretch). The cohesive strength of a material, expressed in psi.
A material which can be repeatedly softened by heating. Thermoplastics generally have little or no chemical crosslinking.
A material which hardens by chemical reaction. Not remeltable. The reaction usually gives off heat.
Nonsagging. A material which maintains its shape unless agitated. A thixotropic sealant can be placed in a joint in a vertical wall and will maintain its shape without sagging during the curing process.
Poisonous or dangerous to humans by swallowing, inhalation, or contact resulting in eye or skin irritation.
Elongation at failure.
Part of the light spectrum. Ultraviolet rays can cause chemical changes in rubbery materials.
Term normally used to refer to one single light of insulation glass.
Total of one width and one height in inches.
A family of polymers ranging from rubbery to brittle. Usually formed by the reaction of a disocyanate with a hydroxyl; also called polyurethane.
Holding glass in place with extruded vinyl channel or roll-in type.
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.
Improving the elastic properties of a rubber by a chemical change.
An environmental chamber in which specimens are subjected to water spray and ultraviolet light.