(2) The
sheets or articles may be dipped in a bath of melted zinc. This gives us
the familiar "galvanized iron," the most useful and when well done the
most effective of rust preventives. Besides these older methods of
applying zinc there are now two new ones. (3) One is the Schoop process
by which a wire of zinc or other metal is fed into an oxy-hydrogen air
blast of such heat and power that it is projected as a spray of minute
drops with the speed of bullets and any object subjected to the
bombardment of this metallic mist receives a coating as thick as
desired. The zinc spray is so fine and cool that it may be received on
cloth, lace, or the bare hand. The Schoop metallizing process has
recently been improved by the use of the electric current instead of the
blowpipe for melting the metal. Two zinc wires connected with any
electric system, preferably the direct, are fed into the "pistol." Where
the wires meet an electric arc is set up and the melted zinc is sprayed
out by a jet of compressed air. (4) In the Sherardizing process the
articles are put into a tight drum with zinc dust and heated to 800 deg.
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