The second drawback the smoke generated from the oil-laden coolant coming in contact with the operating cutting tool. One of the easiest ways to remove hydrocarbons from water or coolant is by using a belt oil skimmer. It is a low maintenance, easy to use tool for removing oil. Belt oil skimmers work because of the differences in specific gravity between oil and water. Water has a specific gravity of one.
Most oils have a specific gravity of less than one.
Because of these differences, oil floats to the top of the water where it can be removed. The belt passes through a set of wiper blades via a motorized head pulley where the oil is wiped off both sides of the belt. The oil then flows through the skimmer troughs and into a proper disposal container. Because the belt materials used do not attract water, very little coolant or water is picked up. Some of the advantages of using a belt oil skimmer over other methods to remove oil are the lower initial cost compared to coalescers and other filtration systems, low maintenance, no filters to change, and no mess involved as with absorbent booms or pads.