Lacquering Metal.
When it is desired to lacquer or coat over metal to prevent any future oxidation (not commonly desired by collectors of antiques) the copper or brass article should be pickled for several hours in aqua fortis diluted with water. The acid will rot away a certain portion of the tarnished surface and leave the metal bright. The article should then be put into bran and well shaken until quite dry. It is then ready to be cleaned, and, if desired, polished bright.
Old brasswork may be relacquered by the amateur with a little experience, practice, and care. First of all it must be cleaned. The liquid which is best suited to the purpose may be made of a strong lye of wood ashes boiled and strengthened with soap lees. This will fetch the old lacquer off. The article should then be dipped in aqua fortis and water to take off the dirt, and immediately removed and cleansed with clean water, and then when dried it is ready to be lacquered. There are two processes in simple lacquering, which may be defined as cold and hot. The cold lacquer is the application of a preparation of brass lacquer, which can be purchased from any oil-shop, chemist, or metal dealer, put on with a camelhair-brush like varnish, and immediately placed in an oven or a hot stove, and exposed to the heat for a few minutes until the lacquer is quite firm and set. A gas-oven such as those in common use in so many kitchens nowadays answers the purpose very well.
The second method is the application of lacquer after the article has been heated. The heating may be done in a gas-oven, or by the application of a flat-iron such as is used by laundresses. Then lacquer should be applied hot, and if the object lacquered has cooled in the process heat should again be applied as in the first process. It should be clearly understood that cleaning and relacquering old brass and copper-work should be done with very great care and with a full appreciation of the curio value of old finish, and of the marks and evidences of age which are so dear to the collector. The pickling of brasswork in acid and subsequent lacquering should only be resorted to when it is absolutely necessary to effect such restoration, and to make the objects sufficiently presentable so that they may be included in a cabinet or exhibited in the collection of metal curios; for the possession of old copper and brass is nothing without the opportunity of showing it. There are some specialists who devote their attention to the restoration and bronzing of mediæval and early ecclesiastical work. It may on occasion be necessary to consult such a firm before attempting anything which would savour of vandalism and rob the present-day possessor and curio-hunter of the future of what might eventually become a rare antiquity.