Maintenance workshops will usually have a variety of greases available to suit different applications. Misidentifying and misapplying grease is an easy mistake to make. It is a mistake however with potentially costly consequences.
Mixing of greases that are incompatible can have serious maintenance consequences. and it is very likely that, if misapplied, some will be incompatible with the grease already in the bearing.
The compatibility of greases is normally related to the different thickener types used in the greases to be mixed, although base oil compatibility is also important.
Mixing incompatible lubricants creates serious problems and is likely to lead to bearing failure. If incompatible grease is inadvertently added to the existing grease in a bearing, rectification is difficult and expensive even if the bearing has not been damaged. Purging most likely won’t remove all the incompatible grease mixture which leaves a complete bearing clean as the next, costly, option.
Compatibility of grease mixtures is typically categorized as follows:
- Compatible – The properties of the mixture are similar to those of the individual grease.
- Incompatible – The properties of the mixture are significantly different than those of the individual.
- Borderline – The properties of the mixture may or may not be acceptable, depending on the nature of the application.
Greases are compatible if the following conditions are met:
- The dropping point of the mixture is not significantly lower than that of the individual greases.
- The mechanical stability of the mixture is within the range of consistency of the individual greases.
- The change in consistency of the mixture following elevated temperature storage is within the range of the change in consistency of the individual greases following elevated temperature storage.
Importantly, different greases that are found to be compatible when mixed may not exhibit the same performance parameters of either grease prior to mixing, so caution is advisable.
As will be clear, where greases that have been mixed are incompatible and no longer meet the original performance requirements of the correct grease for the application, then a bearing failure will likely soon follow with the consequential maintenance costs, production losses and reduction in productivity.
GreaseMax lubricators provide effective, efficient lubrication and a high level of prevention against inadvertent application of the wrong grease.