Abstract: In order to protect free surfaces, especially steel surfaces against corrosion, a water layer is applied thereto, binding it to the surface by means of a gel-forming hydrophilic material which is essentially insoluble in water. The hydrophilic material is preferably a polymer or an inorganic, gel-forming composition. The method may be used for protection of offshore constructions, ships, the ballast tanks of ships, iron and steel pipelines, and the like. It may also be used to coat the interior of asbestos cement pipe to prevent asbestos pollution of a liquid to be conducted by the pipe.

Abstract: To protect the underwater surfaces of a ship against fouling and corrosion, several layers of wax are applied, one layer on top of the next but each layer having a successively lower melting point and/or degree of hardness. After a certain length of time, when the outermost layer of the treated surface has become fouled or roughened in some way, it is thus possible to remove whichever layer is outermost by melting or brushing, since the treatment can be regulated such that the underlying layer(s) will not be affected.

Abstract: A method and means whereby a neutral salt water solution is electrolyzed in a confined compartment to achieve decomposition products which remove adsorbed film and microorganisms from teeth and oral cavity. The decomposition solution is sprayed from a container whereby the compartment is arranged in connection with the spray means. The electrodes in the compartment are activated from a current source.