Scratch Brushing
Articles in relief which do not admit of the use of the burnisher are brightened by the aid of the scratch brush. The shape of the brush varies according to the article to be operated upon. Hand scratch brushes are sometimes made of spun glass, with fibres of extreme fineness and elasticity, and are used for scouring only very delicate objects. They are also made of numerous wires of hardened brass and are prepared in similar form to the glass brushes, except when purchased the ends of the wires are not cut off, the operator being expected to do so before using them. The object in leaving the wires connected being to prevent them becoming damaged. Circular scratch brushes, in which the wires are arranged radially, are used for scouring articles which will admit of their use. They are attached to the spindle of a polishing lathe, and the wires consequently all receive a uniform motion in the same direction. Scratch brushes are seldom, if ever, used dry, the tool and the work being constantly wet with a decoction of soap-root, marshmallow, cream of tartar, alum or licorice root. With small articles the scratch brush is held as you would a pencil, and is moved over the articles with a backward and forward motion. The brushes must be carefully looked after and the wires kept straight and in good order. If they become greasy they are cleansed in caustic potash, and if they become rough they are sometimes dipped into nitric acid. With circular brushes it is well to reverse them occasionally in order to change the direction of the wires. Dirty polishing leathers should be cleaned by soaking them for an hour or two in a weak solution of soda in warm water, first rubbing the leather thoroughly with soap. Rinse thoroughly and wash in soap and water. The soap in the water will keep the leather soft and pliable. Dry it in a towel and rub it thoroughly and your leather will be much better than any new one you can buy.