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Counteracting Coolant Residue in Machining

Seeing the buildup of dried coolant residue in your machine is frustrating. Not only is the downtime needed to clean the machine irritating, but the causes behind it can be puzzling too. AFT, Inc.’s fluid experts have assembled a list of the most common causes of coolant residue in your machine below.

What causes coolant residue in CNC machines?


  1. High concentration
  2. High tramp oil content
  3. Incorrect mixing
  4. Hard water
  5. Heavy misting

How to solve coolant residue problems in CNC machines


  1. Adjust concentration to specifications
  2. Skim off tramp oil
  3. Add concentrate to water. Never add straight concentrate to sump. Mix thoroughly.
  4. Treat water. Install R.O. or D.I. System.
  5. Check ventilation system. Adjust coolant nozzles. Increase coolant flow.

Need to Talk Through Your Problem? Give Us a Call.


To discuss the residue in your machine in greater detail, give AFT, Inc. a call. Our fluid technicians are here to shed more insight on this problem to help you correct it quickly and easily. If your residue buildup is related to the coolant you are using, don’t worry! We have top-of-the-line coolants that can handle even the toughest machining operation.