Significance and Use The compatibility of greases can be
important for users of grease-lubricated equipment. It is well
known that the mixing of two greases can produce a substance
markedly inferior to either of its constituent materials. One or
more of the following can occur. A mixture of incompatible
greases most often softens, sometimes excessively. Occasionally,
it can harden. In extreme cases, the thickener and liquid
lubricant will completely separate. Bleeding can be so severe
that the mixed grease will run out of an operating bearing.
Excessive syneresis can occur, forming pools of liquid lubricant
separated from the grease. Dropping points can be reduced to the
extent that grease or separated oil runs out of bearings at
elevated operating temperatures. Such events can lead to
catastrophic lubrication failures. Because of such occurrences,
equipment manufacturers recommend completely cleaning the grease
from equipment before installing a different grease. Service
recommendations for grease-lubricated