Can hardening grease be diluted with base oil before being reused?
Release date:
2021-12-09
Grease, commonly known as "butter," gets its name from its intended purpose—lubrication. As many experienced technicians know, any part involving rolling or friction—whether it's the axles of large or small vehicles or motor shafts in factories—requires lubrication. Grease is widely used due to its excellent characteristics: high-temperature resistance, antioxidant properties, long service life, and unique paste-like consistency with exceptional adhesion. Next, let’s share some insights into common questions that often arise during the use of automotive grease! 1. After storage, grease becomes harder (its consistency increases). Can I add base oil to dilute it before using? Most greases will increase in consistency (as measured by their cone penetration value) after being stored for a period of time, meaning they become harder. If the change in consistency is no more than one grade, the grease can still be used directly without affecting its general lubricating performance. However, if the consistency changes significantly, it indicates excessive separation of the base oil, which may increase frictional resistance when lubricating mechanical components and lead to higher energy consumption. Such grease should not be used directly. Some users try to dilute hardened (or thickened) grease by adding base oil to reduce its consistency (i.e., soften it) before use. This practice is not recommended, as the lack of proper homogenization processes can degrade the colloidal stability of the grease, leading to increased oil separation and negatively impacting its performance. For grease that has thickened but whose other physical and chemical properties remain relatively unchanged, manufacturers can add the same type of base oil, followed by homogenization and passing rigorous quality tests before it can be safely used. 2. What changes occur to the quality of grease during use? How can we visually identify these changes? In working parts, grease undergoes two types of changes under the influence of external factors (such as air, water, dust, or other harmful gases) and mechanical forces generated by relative motion between components (such as impact or shear). These changes include: ① Chemical changes: The components of grease—base oil and thickener—can oxidize and deteriorate when exposed to light, heat, and air. Oxidation of the base oil produces trace amounts of organic acids, aldehydes, ketones, and lactones. In the thickener, fatty acids and organic metal salts may decompose, forming trace amounts of organic acids. As a result, acidic substances accumulate (leading to an increase in the grease’s acid value), causing corrosion and rusting of the lubricated parts and ultimately reducing their lubricating and protective functions. ② Physical changes: Mechanical forces can degrade or even destroy the grease’s structure, reducing its consistency and diminishing its lubricating effectiveness. Alternatively, poor sealing conditions in mechanical lubrication systems can allow dirt, impurities, and moisture to contaminate the grease, further degrading its quality. Methods for identification: If you notice visible dust or mechanical impurities in the grease, or if it turns milky white or lighter in color due to water contamination and emulsification, or if its consistency noticeably decreases, or if there’s a distinct rancid odor, these are all signs that the grease has deteriorated. 3. What precautions should be taken when storing grease? Grease is a colloidal substance, and its structure can change during both use and storage under the influence of various external factors. When storing grease in warehouses, the temperature should not exceed 35°C, and packaging containers must be tightly sealed to prevent moisture and foreign contaminants from entering. After opening a container to take a sample or product, avoid leaving holes or indentations in the container. Instead, smooth out the surface of the grease after sampling to prevent depressions. Otherwise, the base oil could be squeezed out by gravity and seep into these indentations, compromising the product’s quality. 4. Can different types of grease be mixed together? Generally, greases made from the same type of base oil (e.g., both petroleum-based or other similar base oils) but with different soap bases or thickeners should not be simply mixed. However, certain types of grease—such as calcium-based grease and sodium-based grease, or lithium-based grease and complex lithium-based grease—can be mixed without significant performance changes and won’t affect their usability. But for extreme-pressure greases, which contain various active ingredients, mixing them together can cause additive interactions that degrade the grease’s colloidal or mechanical stability, thereby affecting its performance. Before mixing different types of grease, it’s essential to test the performance of the blended grease first and confirm that there are no noticeable negative effects before using it.
Grease, commonly known as "butter," as its name suggests, is used for lubrication. As many experienced technicians know, wherever there’s rolling motion or friction—whether in large vehicles, small cars, or motor shafts in factories—lubrication is essential. Due to its outstanding features—such as high-temperature resistance, antioxidant properties, long service life, and unique adhesive paste-like consistency—grease is widely used. Next, let’s share some insights into common questions and concerns that often arise during the use of automotive grease!
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Can hardening grease be diluted with base oil before being reused?
Grease, commonly known as "butter," gets its name from its intended purpose—lubrication. As many experienced technicians know, any part involving rolling or friction—whether it's the axles of large or small vehicles or motor shafts in factories—requires lubrication. Grease is widely used due to its excellent characteristics: high-temperature resistance, antioxidant properties, long service life, and unique paste-like consistency with exceptional adhesion. Next, let’s share some insights into common questions that often arise during the use of automotive grease! 1. After storage, grease becomes harder (its consistency increases). Can I add base oil to dilute it before using? Most greases will increase in consistency (as measured by their cone penetration value) after being stored for a period of time, meaning they become harder. If the change in consistency is no more than one grade, the grease can still be used directly without affecting its general lubricating performance. However, if the consistency changes significantly, it indicates excessive separation of the base oil, which may increase frictional resistance when lubricating mechanical components and lead to higher energy consumption. Such grease should not be used directly. Some users try to dilute hardened (or thickened) grease by adding base oil to reduce its consistency (i.e., soften it) before use. This practice is not recommended, as the lack of proper homogenization processes can degrade the colloidal stability of the grease, leading to increased oil separation and negatively impacting its performance. For grease that has thickened but whose other physical and chemical properties remain relatively unchanged, manufacturers can add the same type of base oil, followed by homogenization and passing rigorous quality tests before it can be safely used. 2. What changes occur to the quality of grease during use? How can we visually identify these changes? In working parts, grease undergoes two types of changes under the influence of external factors (such as air, water, dust, or other harmful gases) and mechanical forces generated by relative motion between components (such as impact or shear). These changes include: ① Chemical changes: The components of grease—base oil and thickener—can oxidize and deteriorate when exposed to light, heat, and air. Oxidation of the base oil produces trace amounts of organic acids, aldehydes, ketones, and lactones. In the thickener, fatty acids and organic metal salts may decompose, forming trace amounts of organic acids. As a result, acidic substances accumulate (leading to an increase in the grease’s acid value), causing corrosion and rusting of the lubricated parts and ultimately reducing their lubricating and protective functions. ② Physical changes: Mechanical forces can degrade or even destroy the grease’s structure, reducing its consistency and diminishing its lubricating effectiveness. Alternatively, poor sealing conditions in mechanical lubrication systems can allow dirt, impurities, and moisture to contaminate the grease, further degrading its quality. Methods for identification: If you notice visible dust or mechanical impurities in the grease, or if it turns milky white or lighter in color due to water contamination and emulsification, or if its consistency noticeably decreases, or if there’s a distinct rancid odor, these are all signs that the grease has deteriorated. 3. What precautions should be taken when storing grease? Grease is a colloidal substance, and its structure can change during both use and storage under the influence of various external factors. When storing grease in warehouses, the temperature should not exceed 35°C, and packaging containers must be tightly sealed to prevent moisture and foreign contaminants from entering. After opening a container to take a sample or product, avoid leaving holes or indentations in the container. Instead, smooth out the surface of the grease after sampling to prevent depressions. Otherwise, the base oil could be squeezed out by gravity and seep into these indentations, compromising the product’s quality. 4. Can different types of grease be mixed together? Generally, greases made from the same type of base oil (e.g., both petroleum-based or other similar base oils) but with different soap bases or thickeners should not be simply mixed. However, certain types of grease—such as calcium-based grease and sodium-based grease, or lithium-based grease and complex lithium-based grease—can be mixed without significant performance changes and won’t affect their usability. But for extreme-pressure greases, which contain various active ingredients, mixing them together can cause additive interactions that degrade the grease’s colloidal or mechanical stability, thereby affecting its performance. Before mixing different types of grease, it’s essential to test the performance of the blended grease first and confirm that there are no noticeable negative effects before using it.
We’ve got solutions for all the troubles with gear oil right here!
Gear oils are widely used in industrial applications. Today, taking gear reducers as an example, let’s briefly discuss the common problems encountered when using gear oils and how we can address these issues. 1. Corrosion: This is often caused by the absence of rust-inhibiting additives, moisture in the oil, corrosive extreme-pressure additives, and contaminants—such as acidic substances formed from the oxidation of vegetable oils. To mitigate this, switch to oils with superior rust-prevention properties, drain and change the oil frequently, and prevent contaminants from entering the oil. 2. Excessive Foaming: The main causes include a lack of anti-foam agents, precipitation of anti-foam agents, improper oil level, air entrainment into the oil, and water contamination. Use oils containing anti-foam additives, enhance anti-foaming performance, control the amount of oil added, and avoid letting air or water enter the oil. 3. Oil Leaks: These typically result from damage to the gearbox housing or wear of seals. Use high-viscosity oils and replace damaged seals. 4. Increased Viscosity: This is mainly caused by oxidation and overheating. Use oils with excellent oxidation stability to avoid overheating. 5. Decreased Viscosity: The cause is usually the breakdown of viscosity-enhancing additives. Use additives with high shear stability. 6. Abnormal Heating: This may be due to excessive oil in the gearbox, overly high oil viscosity, insufficient oil quantity, excessive load, or accumulation of dust outside the gearbox that hinders heat dissipation. Control the amount of oil added, reduce oil viscosity, lower the load, and clean the gearbox housing and adjacent metal components. 7. Contamination: This is often caused by debris left over from the assembly of the main unit or machining of parts, as well as contaminants entering through through-holes. Drain the old, contaminated oil, thoroughly clean the gearbox, replace the oil, and prevent contaminants from entering the gearbox through ventilation holes. 8. Abrasive Wear on Tooth Surfaces: This is caused by grinding or other contaminant particles. Replace the oil and thoroughly clean the gearbox. 9. Tooth Surface Burn: This is primarily due to insufficient oil supply or excessive load. Ensure adequate oil levels and reduce the load. 10. Scuffing: This occurs when the tooth surface temperature is too high and the oil film breaks down. Lower the operating temperature and use extreme-pressure gear oils. 11. Pitting: This is caused by low oil viscosity, rough tooth surfaces, excessively high local pressure, and sliding under heavy loads. Increase the oil viscosity, improve the smoothness of the tooth surfaces, and use extreme-pressure gear oils. 12. Galling: This is mainly caused by rough tooth surfaces, installation errors leading to poor meshing, and poor cold-start performance. Improve the smoothness of the tooth surfaces, enhance assembly quality, and switch to oils with better cold-start performance. P.S.: Each specific problem requires a tailored analysis. Only by taking all factors into account can we achieve both machine efficiency and fuel savings, thereby reducing costs.
If hydraulic oil becomes cloudy, identifying the root cause is key to resolving the issue.
Hydraulic oil serves as the power transmission medium in hydraulic systems while also providing a certain degree of lubrication. Therefore, the cleanliness and performance parameters of hydraulic oil directly affect the operation of hydraulic components, thereby impacting the overall performance of the equipment. How to deal with cloudy hydraulic oil? Many machine operators have encountered the issue of cloudy hydraulic oil and impurities in the oil that are difficult to remove. Below, we’ll provide a detailed explanation of this problem. Reason 1 The primary cause of cloudy hydraulic oil is the presence of water mixed into the oil. You can perform a simple test: drop a few drops of hydraulic oil onto a hot steel plate and check whether foam appears. If you can clearly observe bubbles, it confirms that the hydraulic oil contains moisture. If the oil is relatively new and hasn’t been used for long, let it sit undisturbed so that any water settles at the bottom. However, if the oil is nearing its replacement time, you should simply replace it directly. Reason 2 Air has entered the hydraulic oil. When air mixes into the hydraulic oil, it will appear white and cloudy. In this case, the operator should carefully inspect the hydraulic lines for any leaks and eliminate the possibility of air entering from the source. Reason 3 Have you mixed different types of hydraulic oils? Strictly speaking, hydraulic oils of different grades and brands should never be mixed, especially those with significantly varying prices. Mixing such oils can easily lead to cloudiness and subsequently damage hydraulic components. When selecting hydraulic oil, it’s crucial to choose the right type based on the working environment and conditions. The selection process should take into account numerous factors, including operating pressure, temperature, environmental conditions, the structure and material of the hydraulic system and components, as well as economic considerations. For applications involving high operating pressures, hydraulic oils with excellent lubricity and anti-wear properties—such as HL or HM types—are recommended. Reason 4 Is the hydraulic system overheating? If the hydraulic system’s temperature rises excessively, it will inevitably have a significant impact on the oil. For example, prolonged exposure to high temperatures can cause the hydraulic oil to turn black. Therefore, operators must carefully check and confirm whether the hydraulic system is overheating. Reason 5 Is there insufficient hydraulic oil? A low oil level can directly allow air to enter the system. Thus, inspect both the oil suction line and the return line, and do your best to eliminate any sources of air entry.
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