How does water quality affect your coolant abilities?

Water-based cutting oils are normally diluted with water to form an emulsion which offers excellent cooling ability and lubricity and extreme pressure characteristics for effective machining operations. In some cases, diluted coolant can be 70% to 95% water in it.

The quality of the water, which can vary widely by source, region and country, has a significant impact on the emulsion quality and its sump life. However, the water quality is better kept at a proper water hardness before we use it. For example, hard water quality - it will lead to emulsion splitting and a decrease in metalworking performance. And soft water quality will increase foaming while machining.Therefore, we’re going to share how water quality affects coolant abilities? And how to check water hardness?

Hard Water Leading to Emulsion Splitting

Hard water with high mineral content, including chlorides, calcium (Ca), and magnesium (Mg), can detrimentally affect the emulsion quality of the fluid, leaving residues and providing a breeding ground for bacteria. Sulfur and chlorine can also wreak havoc on your coolant, impairing its ability to provide adequate rust protection. If the water hardness is well above 20° dH/350 ppm, it can lead to emulsion splitting and decreased metalworking performance.

Using hard water may cause significant discoloration on steel and aluminum surfaces, formation of lime (calcium) soaps, weakened corrosion protection, reduced emulsion stability, and shorter sump life. Hard water is difficult to mix with coolant, leading to separation of oil and water, and causing part of the concentrated liquid to be consumed in softening the water, thereby increasing costs as more concentrated fluid is needed to ensure performance.

Soft Water Increases Foaming

The water hardness significantly impacts the foam behavior of many metalworking fluid emulsions. Soft water, with a hardness below 8° dH/140 ppm, while not as problematic as hard water, can greatly increase foaming in the emulsion. Excessive foam can lead to operational inefficiencies, equipment malfunctions, and reduced cooling and lubrication performance.

Typically, normal tap water is suitable for the initial filling of the machine, while treated water is recommended for preparing the top-up emulsion. However, some metalworking fluids require soft or even RO (reverse osmosis) water for optimal long-term stability and performance. Using the right water quality is crucial to maintaining the effectiveness and longevity of metalworking fluids, ensuring consistent machining operations, and preventing issues like foaming and emulsion instability. To achieve this, it's essential to monitor and adjust the water quality used in your coolant systems, ensuring it meets the specific requirements of the metalworking fluid in use.

How to Check Water Quality - The Importance of TDS in Water Quality for Metalworking Fluids

Water hardness significantly impacts the foam behavior of metalworking fluid emulsions. Soft water, with a hardness below 8° dH/140 ppm, can greatly increase foaming in the emulsion. Excessive foam can lead to operational inefficiencies, equipment malfunctions, and reduced cooling and lubrication performance. Proper water quality management, including monitoring Total Dissolved Solids (TDS), is crucial for maintaining the efficacy of metalworking fluids.

Total Dissolved Solids (TDS) refers to the total concentration of dissolved substances in water. As water flows through rocks, soil, and other mediums, it dissolves various solids from natural deposits or human activities. TDS includes soluble salts (such as calcium and magnesium ions), ionized organic substances (like ammonium acetate and sodium sulfate), and some heavy metal ions (including chromium, zinc, lead, and copper). TDS levels are typically measured in milligrams per liter (mg/L) or parts per million (ppm). Lower TDS values indicate purer water with fewer impurities, while higher values suggest a higher concentration of dissolved substances.

Water hardness and chloride concentration can be checked on-site using measuring strips. We recommend maintaining water hardness between 50 to 60 ppm. Additionally, many cities and regions provide local water quality information on their websites, which can be useful for ensuring the water quality is ideal for your operation before starting the mixing process.

For optimal performance and longevity of metalworking fluids, it’s crucial to monitor and adjust the water quality used in your coolant systems. A TDS meter is an essential tool for this, as it helps determine the concentration of dissolved solids in the water, ensuring the water is suitable for use in metalworking fluids. Proper water quality management helps prevent issues like foaming, emulsion instability, and decreased metalworking performance. Ensuring proper water quality by monitoring TDS levels and maintaining appropriate water hardness can significantly enhance the performance and longevity of your metalworking fluids, leading to more efficient and effective machining operations.

Enhance Metalworking Fluid Performance with Hai Lu Jye He Cutting Oils

Do you still face issues like decreased metalworking fluid performance or excessive corrosion? It might be time to evaluate your water quality. At Hai Lu Jye He, our cutting oils are specially formulated with anti-hard water properties to accommodate the varying water qualities found in different countries. This ensures a more balanced water composition during use, enhancing the precision and usability of the cutting oil in machining processes.