Sealers, corrosion protection system

Adhesives and sealers can be an important part of a total corrosion protection system. Structural bonding procedures and adhesives for aluminum, polymer composites, and titanium are well established in the aerospace industry. Structural bonding of steel is gaining increasing prominence in the appliance and automotive industries. The durability of adhesive bonds has been discussed by a number of authors (see, e.g., 85). The effects of aggressive environments on adhesive bonds are of particular concern. Minford ( ) has presented a comparative evaluation of aluminum joints in salt water exposure Smith ( ) has discussed steel-epoxy bond endurance under hydrothermal stress Drain et al. (8 ) and Dodiuk et al. (8 ) have presented results on the effects of water on performance of various adhesive/substrate combinations. In this volume, the durability of adhesive bonds in the presence of water and in corrosive environments is discussed by Matienzo et al., Gosselin, and Holubka et al. The effects of aggressive environments on adhesively bonded steel structures have a number of features in common with their effects on coated steel, but the mechanical requirements placed on adhesive bonds add an additional level of complication. 

Epoxy based primer systems remain the best suited for the corrosion protection of magnesium. Cathodic epoxy electrophoretic paints , chromate inhibited epoxy-polyamide primers and high temperature stoving epoxy sealers are used to provide protection up to 180°C. For higher temperature applications up to 300°C, epoxy silicone or polyimide based systems can be used. 

Uses Binder, film-former in paints (printed circuit board coatings, coil, container, conosion-protection, marine, metal, plastics, sealers, tarp, wood varnishes), printing inks (screen printing), primers (adhesion pro-motion/corrosion protection), ceramic compds., sealers, heat-sealable lacquers, two-pack paints, resinous/polymeric food-contact coatings reactive resin in two-pack systems, e.g., crosslinked with melamine/phenolic resins... 

For better protection against corrosion in spot-welded seams, the seams are treated additionally with an elastic adhesive/sealant (spot-weld sealer) based on rubber. Hot-and cold-application systems are in use. 

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