While most fluids break down naturally over time due to their usage in your machines, the main reason why coolants break down is the fact that they’re more easily contaminated with tramp oil, bacteria, metal fines, and more.
Coolants can be more difficult to maintain in your machine, due to the diverse amount of contaminants that routinely enter the system and other related factors that are inherent to using coolants, such as biological growth. As a result, there are different sets of preventative maintenance that should take place on differing frequencies.
Coolant switching and flushing is primarily scheduled via time-based PMs (e.g., monthly, quarterly, ect.), but if something causes your coolant to deteriorate, you’ll want to catch it as soon as possible to limit any damage to your machine. In addition to your time-based PM schedules, it’s important that you test in between for concentration levels, pH levels, and fungus/bacteria.
To help make sure you’re switching out your coolant at the right times, ask yourself the following 4 questions before switching:
1) What is your coolant’s concentration level?
First and foremost, the concentration level of your coolant is THE most important thing to test onsite. Coolants are water-diluted products that are subject to evaporation and carry-off, so it’s common for concentration levels to change the more the coolant is used. You can easily measure the concentration levels with a refractometer right on the plant floor. It is common, and recommended, to have a system in which you can keep track of the machine’s concentration of the coolant for informational purposes when issues may arise. From whiteboards to spreadsheets, there are a number of ways to track this, and your fluid supplier should be able to offer ideas based on their experience.
To keep your coolant bath in its optimum state, you’ll have to add make-up fluid that brings concentration levels back to normal. It’s important to note, however, that you should never use water alone to adjust the concentration of your coolant; instead, it’s vital that a small quantity of coolant concentrate be pre-mixed with the water to avoid any formulation problems. Additionally, the make-up concentration in warm months is likely to be lower than cold months, due to evaporation.
2) What is your coolant’s pH level?
Once you’ve tested the concentration, the next thing you need to test is your coolant’s pH levels. Having the proper pH level is important, because improper levels can lead to increased corrosion and reduced lubricity of your coolant. Testing the pH of your coolant system will also help determine if contamination exists that normally shouldn’t be present in coolant (such as cleaners), or if the fluid bath is nearing the end of its useful life. To test for pH, you can use pH strips or a hand-held meter for a fairly accurate reading. For larger systems, however, your fluid vendor will likely help conduct pH testing for you.
3) How much fungus/bacteria is in your coolant?
Though your coolant can breakdown over time simply due to use, fungus and bacteria can greatly accelerate the process, not to mention cause other operational issues (clogged lines, breakdown of fluid emulsion) or HSSE issues (such as dermatitis, odors, etc.). Not only can there be bacteria in the water used for diluting and mixing, but it can also get into your coolant from the operator’s hands and sweat, the air in your operating environment, and it also lives in the sludge that settles in your machine sumps and machine coolant flumes. If you notice a change in pH, detergency, lubricity, or odor with your coolant, it’s important that you conduct a bacteria check right away, as using spoiled coolant can lead to surface blemishes, decreased tool life, increased foaming, clogged lines, and much more.
In addition to bacteria, fungus is another microorganism that has an even more disastrous effect on your machine coolants. Bacteria are microorganisms that can grow rapidly in fluids and fungi are more fibrous organisms that grow on the surfaces inside your machines (e.g., pipes, lines, filters, etc.). While some bacteria are okay in your coolant up to a certain extent, any presence of fungus in your system requires a complete flush. There are treatments and additives to lower the bacteria in your coolant, but there are very few effective fungicides that you can use. If left untreated, fungus can clog your filters and lines, while also deteriorating your coolant and increasing machine wear. The physical fungus must be removed or it will reappear. Chemical-based cleaning procedures can be implemented to help remove fungus and bacteria from the systems once they’ve entered.
4) Are you going to recycle your coolant?
Recycling your coolant is an effective way to save money on your fluids, but it’s only feasible if your coolant isn’t totally ruined. You don’t want to recycle ‘bad’ fluid, after all, so you’ll have test your fluid’s condition to see if it’s capable of being recycled. If any fungus is present, regardless of the amount or sump size, it’s crucial that you stop recycling and flush your system right away. A robust fluid recycling system will have different levels of physical filtration, oil removal, and other features to properly condition the coolant for reuse, including distribution methods.
Still have questions about when you should be changing or coolant, or wondering how you can effectively extend the life your coolant? At U.S. Lubricants, we offer a wide variety of different coolants and preventative maintenance equipment for extending coolant life. Our custom-blended fluids can be formulated to fit the exact needs of your operating environment, helping prevent issues with oxidation, wear, lubricity, and more. Contact Tony Springer at TSpringer@uslube.com to learn more about how U.S. Lubricants can help you solve your coolant challenges, or reach out by phone at (800) 490-4900 ext. 8823.