Battery Process 59

    Weigler’s Process 60

    Hern’s Process 60

  Section VII.

  Galvanizing. 61-66

  Index. 67-69

HANDBOOK ON JAPANNING.

SECTION I.

Introduction.

Japanning, as it is generally understood in Great Britain, is the art of covering paper, wood, or metal with a more or less thick coating of brilliant varnish, and hardening the same by baking it in an oven at a suitable heat.  It originated in Japan—­hence its name—­where the natives use a natural varnish or lacquer which flows from a certain kind of tree, and which on its issuing from the plant is of a creamy tint, but becomes black on exposure to the air.  It is mainly with the application of “japan” to metallic surfaces that we are concerned in these pages.  Japanning may be said to occupy a position midway between painting and porcelain enamelling, and a japanned surface differs from an ordinary painted surface in being far more brilliant, smoother, harder, and more durable, and also in retaining its gloss permanently, in not being easily injured by hot water or by being placed near a fire; while real good japanning is characterised by great lustre and adhesiveness to the metal to which it has been applied, and its non-liability to chipping—­a fault which, as a rule, stamps the common article.

If the English process of japanning be more simple and produces a less durable, a less costly coating than the Japanese method, yet its practice is not so injurious to the health.  Indeed, it is a moot point in how far the Japanese themselves now utilize their classical process, as the coat of natural japan on all the articles exhibited at the recent Vienna exhibition as being coated with the natural lacquer, when recovered after six months’ immersion in sea water through the sinking of the ship, was destroyed, although it stood perfectly well on the articles of some age.  In the English method, where necessary, a priming or undercoat is employed.  It is customary to fill up any uneven surface, any minute holes or pores, and to render the surface to be japanned uniformly smooth.  But such an undercoat or priming is not always applied, the coloured varnish or a proper japan ground being applied directly on the surface to be japanned.  Formerly this surface usually, if not always, received a priming coat, and it does so still where the surface is coarse, uneven, rough, and porous.  But where the surface is impervious and smooth, as in the case of metallic surfaces, a priming coat is not applied.  It is also unnecessary to apply such a coat in the case of smooth, compact, grained