SCIENCE NOTES.

Hutt News, Volume 3, Issue 9, 24 July 1930, Page 3

SCIENCE NOTES.

A WONDEBFTTL PISTOIi.

For .yeaTs a, distinguished Swiss seien*. ■tis.t at. Zurich has been trying to make paper for bank notes which will neither wear out nor burn.H© now claims that he can spray paper pulp with pure tin, and that -his process docs not injure the fibre. TJhe sheetar are practically indestructible, yet are clastic. He intends also to use these metallised paper plates iin wireless work and telephones, where i their value will be considerable. x Tho pistotl used in this metal-spraying process is a wonderful' little portaible machine. It consists of a nozzle containing an oxy-acetylene flame. The metal to be sprayed is forced through, the flame from the 'back of tihe pistol by an air turbine, by way of a regulating •valve.. On emerging from the flame, the molten metail is atomised by compressed air. The spray is so 'exceedingly fine that it is instantly cooled on Teaching" its. goal, and may be used to coat any material, however delicate or inflammable. *, ' . The coating may be of any. thickness^ may be-built up one over th© other, and , cannot be hammered off. One of tiha pistol 's most important uses is to coat machine parts with zinc or tin, making them non-corrosive. Another is to build up-, baddy,worn shafts and ball-ibearings, t coat by coat, to their original shape and , size, using a hard metal, like nickel. When they are thus treated, and machined smooth, they are said, to be more hard-wearing than when new. Wood so coated will not rot. Glass can be lead or silver coated, even inside tuibes and; cylinders. The commercial possibilities j are said to be unlimited.