Hot-Metal Gun

A pint-sized gun that shoots a spray of molten metal is saving U.S. wartime industry hundreds of thousands of dollars and hours of labor. The Army & Navy have 750 of these hot-metal guns in use this week. Aircraft makers are using thousands. The new tool is indispensable in 1) the manufacture of airplanes; 2) their maintenance by the Army & Navy; 3) the repair of ailing machinery which, owing to the dearth of metals and machining facilities, would be scrapped or stand idle.

The spray gun is a fist-fitting gadget which trails three rubber hoses and a 1/8-in. wire--the charge. Two of the hoses feed acetylene and oxygen (as in welding) to a 6,300DEG F. flame, melting the wire. From the third hose, compressed air blows the hot-metal droplets in a molten mist that coats a surface with a smooth film as tough as a weld.

Peacetime use of the hot-metal gun was to coat baby shoes with bronze or silver (for keepsakes). Some wartime uses:

> Patching up surface flaws in aircraft castings, which have hitherto been rejected and junked.

> Facing aircraft cylinder heads and other exposed steel parts with aluminum to prevent corrosion by weather, salt sea spray and engine heat (as in exhaust manifolds).

> Facing light metals (like aluminum) with more durable metals like steel). Example: the gun rings of bomber turrets.

> Maintaining industrial equipment. One massive 9 1/2-ft., 2,400-lb. Diesel crankshaft was worn at its bearing points. Wartime replacement was impossible; in any case, would have taken twelve weeks. A hot-metal sprayer, using 45 lb. of steel wire, resurfaced the worn shaft in ten hours.

This file is automatically generated by a robot program, so reader's discretion is required.