Unwanted oil within a machine tool can reduce the quality life of the cutting fluid. Two common reasons for excessive free oil are leaky seals on the machine tool and processing raw materials that have oil in them.
You may want to consider speaking with your coolant representative to determine how free/tramp oil impacts your coolant. Companies that combat this issue have used different methods to remove the free/tramp oil including but not limited to:

- Sump sucker – suck off the top layer of tramp oil when needed
- Decanting – works with some water-based coolants
- Centralized coalescer
- Machine side coalescer
- Sump side oil skimmer
Due to the wide range of methods used, many industry veterans have suggested monitoring your system’s success is almost as important as the method itself. Just like testing the water sources, keeping records of free/tramp oil levels, amount removed daily, routine maintenance on equipment, and observations can be beneficial to develop trends for each machine tool. How does a plant know if their investment to remove free/tramp oil is giving them the return they expect without appropriate documentation?