Deposition anaerobic adhesives

Seals based on anaerobic adhesives will even function close to the combustion chambers and exhaust ports of an engine. Oxidation of the sealant and the deposition of other debris slowly replaces the adhesive with a carbonaceous, metal- and rust-impregnated material which functions effectively -- if not intentionally Note that ... 

The rate of chemical degradation above 200°C as well as general performance depend largely upon the components used, the working environment and the adhesive type employed. Some of the newer, toughened, anaerobic adhesives will seal cylinder liners adjacent to exhaust ports, because, although decomposition takes place, degeneration is not so rapid that the adhesive is completely destroyed before natural deposits have built up to maintain the seal. 

Anaerobic adhesives have been available for many years in a micro-encapsulated form. Fasteners are coated by deposition from a slurry. When dry the fasteners can be stored until required. Whilst this approach has obvious benefits for on-part inspection these products have had limited success due to shelf life problems and inconsistent locking performance. ... 

Newer adhesives of the acrylic, anaerobic or radiation-curable types must, if they are structural, have a relatively high degree of toughness and durability if they are to compete with or challenge epoxy adhesive systems. Likewise, newer radiation-curable, pressure-sensitive adhesive systems must exhibit the properties of permanence largely associated with cross-linked adhesive masses deposited from an acrylic solution polymer base. Epoxy resin structural adhesives largely define the existing area on the one hand the cross-linked acrylics deposited on plastic or metallic films the other. 

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