Care of Metal.
All metal equipment should be kept clean and free from rust. Coal oil is used to remove rust, but it must always be removed as it will rust the metal if allowed to remain. The coal oil should be applied to the metal and if possible allowed to remain for a short time. This will loosen and partially dissolve the rust so that it can be rubbed off with a rag or a sponge. Continued applications may be necessary if there is much rust. A solution of Sal Soda is also a good rust remover. The articles must be washed thoroughly after using this to remove all traces of the soda as it is a very active corrosive. Never scour metals to remove rust if it can be avoided as this leaves a roughened surface which will rust again much more easily. Polished surfaces such as brass fittings should be cleaned and polished with Lavaline. This may also be used on the bearing surfaces of steel collars. All surfaces after cleaning should be dried thoroughly and if not painted should be greased with cosmis or cosmoline. These form an air-proof coating over the metal surface so that no moisture may reach it and cause rusting. If the metal is not dried thoroughly, some moisture may be held between the grease and the metal surface which will in time cause rust to appear. Care must be taken that the grease covers the surface completely. All surfaces against which there is no friction should be painted and kept so. Ordinary olive drab or collar paint is very satisfactory for this purpose.