METAL SPRAYING.

Press, Volume LX, Issue 18266, 27 December 1924, Page 15

METAL SPRAYING.

A USEFUL INNOVATION. At. a moctmg of the Institute of Metals held recently at the Jnstitut? of Mcchanicsl Engineers, London, an account, was given of the advances made in metal spraying by Mr T. H. Turner and Mr M". U. Ballard. The method (as described in the "Morning Post'' report,) consists of treating metals of practically every description as if t-key were scont in a scent spray, and depositing tbrm on any desired object in t.h« form of a fin? adherent dust. The metal surfaco thus obtained can ho burnished or polished to any degree and is permanent. The spray is produced and projected by an instrument, resembling a large automatic pistol, hut. the magazine, is loaded with :i r;el of wire in place of cartridges, and the propulsive charge is composed of oxygen, hydrogen, and compressed air. As the wire reaches the muzzle it is converted into a cloud of tiny metallic particles, which, travelling at a very high speed, become, molten on striking the target, nn:l form a solid coating. In spite of the great heat of the osy-hydrogen flame used in vaporising the metal, the most delicate, as well as the most robust, materials arc undamaged by the process, and of I this many interesting emmpTes were shown. Designs produced by spraying silk and cotton fabrics with brass and copper alloys were shown, the method bein? to place a paper stencil over the material and direct the pistol on it. Fabrics are not affected by washing. F.vcn thin paper is not scorched, and the palm of the hand can be plated with pure metal without discomfort, and glass can also be coated in the same manner. The* industrial applications are many, and are now beiug used in six European countries, as well as in America. A coating of any thickness of non-cor-rosive metal can be applied to any structure, thus preserving it from the action of weather or chemical fumes — a matter of great importance in shipbuilding and engineering in general. It is possible to spray a non-norous coat of tin. lead, or stine. on any object, and alsri to preserve wood by spraying it | with rustless iron.