Page:The Cycle Industry (1921).djvu/55

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slab of the nickel to the steel. Various methods are used, and some highly ingenious machines have been devised for rapid plating of small articles. The latter are strung on wires like the Chinese carry money, and hung from metal rods which are charged with an electrical current of low voltage. The other pole of the electric current is connected to the nickel slab (anode) and the nickel passes from the anode to the steel to be plated. When the parts emerge from the bath they are dull plated and resemble unpolished aluminium; therefore, before being sent to the finishers or finished stores they have to be polished again on the before mentioned calico mops or wheels.

The polished work to be enamelled has to be chemically treated to remove all grease, and in some instances baths of heated patent liquid are employed. Some makers are content to clean the parts with a grease removing spirit, like turpentine. When clean, the frame, fork, mudguards, etc., are either dipped in liquid black enamel and hung up to drain or liquid enamel is poured over them. When the superfluous enamel has drained back to the sump of the pan the parts are lifted on hooks (the enamelled surface must not be touched with the hand) and hung in gas heated stoves, where they are baked at a high temperature for a few hours. The very best bicycles receive at least three coats of thin enamel and are stoved between each application. The resulting surface, when cold, should resist blows with a wood broom handle without cracking.

Enamelled and plated parts are handled by the assemblers in the finishing shops in different ways, according to the organization in different factories, but a common method is to have an iron pillar standing up at the edge of the bench, the steering tube of the frame, minus the fork, is dropped over the pillar and the