Extreme care must be given by the machine tool operator in maintaining cutting coolants at its right concentration. Coolants at the right concentration ensure that the coolant is at its optimum performance at all times, in terms of:
- ) Lubricity, ensuring proper tool life and surface finish,
- ) Rust and corrosion control
- ) Stability (no oil separation)
- ) Bio-resistance
The recommended concentrations vary depending machining or grinding job, but the guidelines below are generally accepted.
While maintaining concentration may seem obvious, many machine tool operators do not have a means to measure concentration effectively. An easy way to perform a concentration check is through the use of a refractometer, an optical device designed to measure sugar concentration in juice drinks. Refractometers have been widely adapted in the metalworking industry.
A quick view on the eye-piece provides a good reference point for concentration, from which a machine tool operator can make a decision to top-up with a ‘stronger-mix’, or a ‘weaker’ mix, depending on the result taken.