Closed-cell polymer foams for corrosion control in confined metal spaces

The use of closed-cell plastic polymer foams to control corrosion in hollow , Irregular cavities of preexisting metallic structures or assemblages was explored The method involved blocking the access of corrosive species to th e interior surfaces by filling the empty spaces with an expanding, polymeri c, rigid foam material The fact that the foam could be injected from a remo te location and then expanded to fill the void solved the problem of access ibility, which precluded the use of traditional corrosion preventive coatin gs in these areas. The approach differed from prior studies in that it focu sed on postdesign applications of corrosion inhibition within confined regi ons. Results of laboratory seawater exposure tests using structural steel t ubular specimens with interior surfaces that were as-manufactured, precorro ded, or protected with a paraffin-based corrosion preventative and filled w ith a one-part polyurethane foam were discussed in the context of the foam' s ability to prevent water penetration to the metal interface. Effectivenes s of the method for corrosion control was demonstrated through visual compa risons of metal deterioration In treated and untreated specimens.