Paint for Iron-Work.

Manufacturer and builder 4, 1894

In the course of a paper read by W. Thomson at a recent meeting of the Manchester Association of Engineers, on the different paints and varnishes used for the preservation of structural iron and steel from rust, the author stated that from experiments made by him he had arrival at the conclusion that red lead paint is the best preservative. This result had struck him as remarkable, because red lead is a highly oxidizing substance; but the reason was found to be that the red lead had the effect of producing a skin of the unoxidizable and protective black or magnetic oxide on the iron itself under the paint. The author also found that other ozidizing agents, such as manganese dioxide, form a paint which preserves iron from rusting; and this discovery he regards as of great industrial importance. Mr. Thompson explained that, having been reuqired some time ago to make a considerable number of experiments to ascertain the most suitable paint for protecting a large iron structure from the action of sea water spray and rain, he arrived at the conclusion that red-lead paint was the best he could find for the purpose.