Machinery Lubrication magazine published by Noria Corporation
Issue link: http://www.e-digitaleditions.com/i/934530
26 | January - February 2018 | www . machinerylubrication.com In the amusement park's maintenance area, I learned that the park was experiencing a rash of motor bearing failures. With such a long operating history, it was surprising to find this sudden uptick in problems. I brainstormed some possible reasons with the maintenance team and was told, "Our motors had been running great ever since Henry took over the motor rebuild program." When I asked if we could discuss the issue with Henry, I was informed that he had retired the previous year. With a little more investigation, we discovered that Henry had been personally sending a new tube of grease with each motor sent out for rebuild, attaching it to the motor with duct tape. When Henry retired, this prac- tice was lost, and the motor rebuild shop reverted to its standard bulk grease. As you may have guessed, the amusement park was using a grease that was not compat- ible with the one at the rebuild shop — not very amusing! Henry had developed an effective strategy to avoid the negative consequences of grease mixing: ensuring that one product — the correct grease for the applica- tion — was being used by everyone servicing the motors. is starts by validating the product, including the right base oil viscosity, base oil type, NLGI grade, thickener type and additives. But even when you know the right grease to use, the opportunities for the wrong grease to be mixed are many. ese would include someone grab- bing an incorrect grease gun, new machines or bearings coming supplied with a different grease, contractors adding the wrong grease during repairs, and grease guns being incorrectly labeled. Determining Incompatibility Just like Henry's motor shop, those who have experi- enced grease mixing have seen the impact. Most times, the greases soften. e thickeners interact and become runny. In some cases, the thickener bleeds excessively, releasing large amounts of the vital oil and additives, which leaves behind mostly thickener. In a few instances, the mixed grease can harden. ese most obvious signs of incompatibility of the "soap" or non-soap thickener have driven an oversimpli- fication of the approach to grease mixing. An internet search will return no fewer than 17 different compati- bility charts which only address families of thickeners. An article in the January-February 2017 issue of Machinery Lubrication cited several examples of grease mixtures that appear to be compatible according to these popular charts, but after a more thorough review obviously are Simple as Soap? The Risks of Grease Mixing GREASES Rich Wurzbach | MRG Labs 53% of lubrication professionals say grease compatibility has caused problems at their plant, according to a recent poll at MachineryLubrication.com