Hand application of gear lubricants, while often used on slow speed exposed gearing, should be discouraged because there is always a certain amount of hazard to such a procedure, the amount of lubricant used is indeterminate, and the operation is wasteful of both time and lubricant. However, primarily because of the lower initial cost, open gears have considerable use. Also, both location of the gears and immediate economy, dictate hand application of lubricants to such gears. Consequently, some of the methods of hand application follow:
(1) By paddle, when the lubricant is a heavy residual type or consists of a solid or stiff grease. Usually more of the lubricant than is necessary is applied and consequently the excess either drops off or is thrown off into the surrounding area. This is not only wasteful but also contributes to poor housekeeping.
(2) By hand in case the residual type is heavy enough. Such a product can be formed into a ball by hand and then dropped into the gear mesh where in time it is distributed.
(3) By bags, made of plastic, most often polyethylene, which is filled with the gear lubricant. A filled bag is dropped between the gear teeth where eventually it is chewed to pieces by the gears and the lubricant is released. This makes a somewhat cleaner operation than the previous methods and the hands are not soiled while applying the lubricant. If a large opening is provided in a gear case, this method of application can sometimes be used for enclosed gears.
(4) By pouring from a can, bucket, or any spouted container. Such applications are made at intervals and in case of gear oil is very heavy, it may require heating to reduce the consistency before applying. The lubricant is then poured in a fine stream into the teeth as the gears slowly revolve toward each other. If the oil is applied relatively frequently in small amounts rather than at longer intervals in large amounts, there will be less chance of its being thrown off.
(5) By hand spray at intervals, most often from “ AerosoI” containers. Such a package, which ordinarily holds up to a pound of a diluted gear compound, makes for ease of application and cleanliness because an excess of the lubricant is not applied. The gear compound is diluted with a non-inflammable solvent which evaporates rapidly after release from the container and leaves a viscous coating on the gear teeth. While the diluents present may be toxic, the amount released at one application is normally so small that it dissipates without harmful effects.
