Iron corrosion; anti-fouling and anti-corrosive paints . mateiial is required, and renewal is lessfrequently necessary than in the latter waters. On the question of paints for non vessels, P. Schwarzsays : The object of the paint is to preserve the shipsbottom from corrosion or incrustation, and to colour thevessel above the water line. In the case of warships thiscolour should be inconspicuous, and for vessels in tropucalwaters should be sucli as will exert a favourable influence on lEON-CORROSION AND ANTI-CORBOSIVE PAINTS. 217 the internal temperature of the ship. In steel or iron vesselsthe
Iron corrosion; anti-fouling and anti-corrosive paints . mateiial is required, and renewal is lessfrequently necessary than in the latter waters. On the question of paints for non vessels, P. Schwarzsays : The object of the paint is to preserve the shipsbottom from corrosion or incrustation, and to colour thevessel above the water line. In the case of warships thiscolour should be inconspicuous, and for vessels in tropucalwaters should be sucli as will exert a favourable influence on lEON-CORROSION AND ANTI-CORBOSIVE PAINTS. 217 the internal temperature of the ship. In steel or iron vesselsthe principal point is preservation from rust, oxygen beingpresent in large proportion in the air, the water, and partlyalso in the carbon dioxide of the bilge water. Moreover, the scale (proto-peroxide of iron) produced inrolling the steel and iron plates, and the varying degrees ofhardness of the surface developed during the working of theplates, give rise—in presence of sea water—to a galvaniccurrent which leaves deep pittiugs of rust behind. Kust. Pig. 61 (natural size).—Peeling anti-fouling composition after six monthsimmersion in %¥ater. itself also forms a galvanic current with iron in presence ofsea water, decomposing the latter, which then yields up itsoxygen to oxidise the iron, whilst the liberated hydrogenpresses up the paint and contributes to its destruction. Consequently the preservation of the hull, and especiallythe protection of the bottom from corrosion by rust, isattended with great difficulties ; and though a number ofcompositions have made their appearance there is none thatfulfils all requirements. Such paints must be insoluble in 218 mON-CORROSION AND ANTI-CORROSIVE PAINTS. water, and sufficiently elastic to give a little and thus preventcracking, but at the same time possess a certain degree ofhardness to oppose sufficient resistance to mechaijical conditions are best fulfilled by a thin layer of resin ;consequently many ships paints ar
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectcorrosionandanticorr
