CORROSION RESEARCH ROUND‐UP

ITALY Coating of metal with polyethylene. Polyethylene shows no particular degree of adhesiveness on metal surfaces. The following technique alone will give satisfactory results: an intermediate layer of polyvinyl alcohol or polyvinylformal or polyvinylbutyral is sprayed on with a flame spray gun, forming a crinkly coat. As soon as this undercoat has been applied the first polythene coat is sprayed on. This will homogenise the intermediate layers and give a smooth and even coat. The intermediate layer is sprayed on by blowing 80 to 100 g. of polyvinyl‐acetate powder per sq. m. of surface through a flame gun. The polythene is then applied in one, or preferably more, coats. Dry air is an excellent carrier for the powders, and the gun is operated with propane or hydrogen. —(G. Guzette, Ind. Vernice, 7 (12), 319–320.)