A variety of adhesive types are
\navailable for many different
\napplications, including insulation attachment, insulation-fitting fabrication, and facing. Adhesives are available in water-based, solvent-based, hot
\nmelts,
\nreactive-cure, pressure-sensitive, and aerosol formulations. These adhesives can be applied through
\nnumerous methods, including brush, spray, trowel, and roll coater. When selecting an adhesive, the insulation
\ntype, service-temperature limits, application method, and required adhesive strength should all be considered. Refer to the adhesive manufacturer’s
\nproduct
\nselection guides for assistance in choosing adhesives for specific uses. In all cases, regardless
\nof the type of adhesive used to secure the insulation, it is important to prepare the surface being adhered to. It
\nmust be free of dirt, rust, loose particles, and oil. Wiping the surface with denatured alcohol is often
\nrecommended. Ambient and surface temperature are also important considerations when selecting an
\nadhesive. When considering ambient temperatures, it is essential to factor in the temperature over the entire curing time. The surface being bonded to
\nmust also
\nbe considered. Steel (coated or painted), plastic (such as polypropylene), or others, may require
\nspecial preparation work or adhesives.<\/p>\n
For attachment and fabrication, rigid insulations will usually require thicker, high-bodied adhesives capable
\nof filling small gaps, while flexible insulations such as fiberglass, mineral wool, or elastomeric use thinner
\nadhesives with a higher coverage rate. Attachment or fabrication of impermeable insulations will require contact,
\npressure-sensitive, or reactive-cure adhesives to avoid trapping vapors. Water-based adhesives are not recommended. When using contact adhesives, it is
\nimportant
\nto coat both surfaces with a thin coat of adhesive (a thin coat is better than a thick coat),
\nand to allow the solvents to evaporate before combining the 2 surfaces. This may vary with installation conditions (temperature and humidity). When
\nusing pressure-sensitive adhesives, it is important to apply pressure to ensure the adhesive is wetted out between the 2 surfaces being adhered. As the
\ninstallation
\ntemperature gets colder, the amount of pressure to wet out the adhesive increases.<\/p>\n
Other specialty adhesives include cryogenic adhesives for very cold operating systems (down to -320\u00b0F), and high-temperature inorganic adhesives for
\nhot work (up to 800\u00b0F). When used for attachment, most adhesives are used in conjunction with mechanical fasteners.<\/p>\n
Duct-Liner Adhesives<\/strong><\/p>\n Duct-liner adhesives include water Reinforcing fabrics for cements and mastics are critical to prevent cracking over seams or areas of movement, and to improve the overall strength of the finish. They come in a variety of types Sealants can be broken up into the following general categories:<\/p>\n Duct Sealants<\/strong><\/p>\n Duct sealants come in a variety of formulations. Typically the sealant is a high-bodied water or solvent-based formulation applied by brush or cartridge gun. UL-181 A-M for duct board Flashing Sealants<\/strong><\/p>\n Flashing sealants are used to seal insulation terminations, penetrations, and protrusions that occur around valves, gauges, and other areas where the insulation is broken. They may also Joint Sealants<\/strong><\/p>\n Joint sealants are used to seal the longitudinal and circumferential butt joints of rigid insulation against moisture penetration. Joint sealants are There are a wide variety of additional accessory products required for successful installations of These accessory products are readily available from a number of vendors.<\/p>\n","protected":false},"excerpt":{"rendered":" Adhesives A variety of adhesive types are available for many different applications, including insulation attachment, insulation-fitting fabrication, and facing. Adhesives are available in water-based, solvent-based, hot melts, reactive-cure, pressure-sensitive, and aerosol formulations. These adhesives can be applied through numerous methods, including brush, spray, trowel, and roll coater. When selecting an adhesive, the insulation type, service-temperature<\/p>\n","protected":false},"author":[],"featured_media":0,"template":"","categories":[38,298,301],"class_list":["post-6847","articles","type-articles","status-publish","hentry","category-material-selection","category-installation","category-design"],"acf":[],"yoast_head":"\n
\nand solvent types as well as pressure-sensitive adhesive and hot melts. They
\ncan be applied in a sheet metal shop
\neither as part of a coil line or on
\nfabrication tables. Typical duct-liner
\nspecifications require 2 forms of
\nattachment; generally, weld or stick
\npins and an adhesive are used. On coil
\nlines, the adhesive is often water based
\nto allow for immediate weld-pin
\nplacement without concern for flash
\nfire. Water-based adhesives do not work
\nwell with closed cell foam duct-liner
\nmaterials because the water cannot
\nevaporate. Hot melt, spray adhesives, or
\npressure-sensitive adhesives are often
\nused on these products.<\/p>\nReinforcements for Cements and Mastics<\/h2>\n
\nand sizes. The reinforcement chosen must be of the correct type and size, and be compatible with the mastic or cement to ensure proper function. Refer to the mastic or cement manufacturers’ product
\ndata sheets for compatible reinforcements. Fiber fabrics include open-weave fiberglass, synthetic fiber meshes, woven canvas, and fiberglass cloth. Mastics are typically reinforced
\nwith 10″ x 10″ open-weave cloths for most applications. Heavier duty 5″ x 5″ mesh cloths are sometimes used with heavier coats of mastics. Reinforcements should always be embedded within the wet
\nmastic or cement and be fully covered. All seams in the fabric should be overlapped by a minimum of 2 inches to avoid the potential for cracking.<\/p>\nSealants<\/h2>\n
\n
\n
\nand UL-181 B-M for flexible and rigid metal duct give standard requirements for duct sealants that may be used to specify them. Metal ducts should also
\nmeet the Sheet Metal and Air conditioning Contractors National Association (SMACNA) pressure standards for the duct system being sealed. Refer to the duct sealant manufacturer’s
\nproduct data sheets and material selection guides for more information.<\/p>\n
\nbe used to seal metal-jacketing seams. Flashing sealants protect the exterior of the insulation system from the ingress of liquids or vapors. The flashing sealant must be compatible with
\nall the surfaces it comes in contact with, including the insulations and insulation finishes. It should be applied per the manufacturer’s instruction in order to create a
\nwatertight seal.<\/p>\n
\nof
\nparticular importance in cold-temperature systems to lock out water
\nvapor penetration between blocks of insulation. Joint sealants are made using high solids and are available in a
\nvariety of types. The joint sealant should remain flexible after application to allow for movement in the insulation
\nsystem without cracking or splitting. Selection of the proper joint sealant will depend upon the operating
\ntemperature at the point where the sealant is applied, the insulation type being sealed, and the finishes being
\napplied over the top of the insulation. Refer to the manufacturers’ product data
\nsheets and product selection guides for more information on the selection and application of joint sealants.<\/p>\nOther Accessory Products<\/h2>\n
\nmechanical insulation, including:<\/p>\n\n
\n
\n