How to increase the safe lifespan of your cutting fluids

Years of Safe Service Life for Cutting Fluids

The lifespan of water-miscible cutting fluids can easily extend to several years without deterioration causing safety or technical issues. This is already a reality for many machine shops. So, what do these machine shops have in common?

The answer is fluid maintenance. Without effective maintenance, cutting fluid quickly loses its properties and eventually degrades. Maintenance always starts with two fundamental aspects: continuous monitoring and excellent cleanliness. Why Monitoring and Cleanliness Matter ​

Monitoring, which essentially means measuring and reporting results, allows you to respond to fluid changes before they cause significant harm. Cleanliness, on the other hand, ensures that the fluid’s properties do not degrade or change too quickly.

Together, these factors enable a safe and efficient fluid lifespan of several years.

How Is This Achieved in Practice?

First of all, it is important to determine whether to focus on problem-solving or prevention. Prevention is naturally much more efficient than correction, as it keeps the fluid consistently in good condition. Once damage has occurred, it is impossible to restore the fluid to its original state.

The first priority is cleanliness. Cleanliness means that the fluid is free from metal, cast iron, or other particles, as well as leakage oils. Maintaining a high level of cleanliness is essential, as contaminants cause rapid fluid degradation. For instance, when filtering, it is important to remember that as particle size decreases, its surface area grows exponentially, leading to a large reactive area, which in turn accelerates fluid degradation. Moreover, the smallest particles tend to move efficiently with the fluid to the cutting tool, causing excessive wear and quality issues.

In addition to cleanliness, the most important factor in problem prevention is maintaining an accurate situational picture. This means measuring the condition of the fluids regularly and comprehensively.

Measuring once a week is significantly better than not measuring at all, but in this context, the rule “the more frequently, the better” also applies, as changes are often very rapid. For example, the pH value in fluids can change significantly in less than 24 hours, and since it is one of the most critical parameters, frequent measurements are crucial. Preventing problems requires quick responses, which in turn requires continuous, preferably real-time, data on the fluid’s condition.

General Steps for Problem Solving  (Applicable to Most Water-Miscible Fluids):

• Maintain the fluid concentration precisely within recommended values. Both too low and too high concentrations cause issues.
• Maintain the fluid's pH level. React to changes promptly, as early intervention requires smaller corrective actions and reduces the severity of problems.
• Clean the fluid from chips and micron-sized particles as quickly as possible. Many issues are proportional to the particle surface area and exposure time rather than the mass. Larger chips and contaminants accumulate in the tank, promoting microbial growth by creating anaerobic conditions while also reducing tank capacity.
• Remove leakage oils as quickly as possible since they cause various problems. Use effective and reliable methods, and, if possible, ensure that the guide oils and cutting fluids in use are compatible.
• Measure the water hardness and ensure it is not too high. If necessary, purify the make-up water from ions, bacteria, and other impurities.
• Continuously circulate the fluid to ensure proper aeration.
• Measure, measure, and measure. Record the results and react in time, even during holidays and weekends if possible.
• Monitor measurement trends to understand how changes affect the cutting fluid. This information can also be used for safety and environmental audits.

Preventing fluid degradation is far more effective than trying to fix it later, and the end result is also better. Aim for frequent measurement and adjustment intervals without interruptions, record the results, and always keep the fluids clean to achieve excellent results.