A Comprehensive Guide to Oil Skimmers for CNC Machine Shops

A Comprehensive Guide to Oil Skimmers for CNC Machine Shops

Discover The Best Oil Skimmers For Metalworking Machine Shops In This Essential Guide

Uncover leading oil skimmer technologies for metalworking machine shops in this comprehensive guide. Delve into how tramp oil skimmers combat oil contamination in CNC coolant systems, enhancing cleanliness, machine performance, and compliance with environmental standards. Optimize your operations with solutions that cut maintenance costs and boost efficiency.


Tramp oil, the oil that leaks from machines into coolants, severely impacts the effectiveness of these coolants and the overall operational efficiency of CNC machines. The accumulation of this oil degrades the quality of the machining process and poses health risks and environmental hazards. This guide is designed to navigate the intricacies of oil skimming technology, focusing on its application within CNC machining facilities. It will cover various types of oil skimmers, explain the scientific principles behind the technology, and provide practical advice on selecting, installing, and maintaining the right oil skimmer for your needs.

By integrating both technical descriptions and discussions of the business benefits, this article aims to serve as a comprehensive resource for both floor technicians and decision-makers in the CNC and metalworking industry.

Enhance your operational efficiency, extend the lifespan of your coolants and tools, and ensure your processes comply with the latest environmental regulations by understanding the role and benefits of oil skimmers.

What is Oil Skimming and How Does It Work?

Oil skimming is a critical process used in industrial settings to remove oil, grease, and other hydrocarbons from the surface of liquids, primarily water-based fluids. In CNC machine shops and metalworking facilities, it plays a pivotal role in maintaining the quality and efficiency of coolant systems by extracting tramp oil that leaks into these systems from machinery.

The fundamental principle of oil skimming involves the separation of oil from a fluid, where the oil, being hydrophobic and less dense than water, naturally floats to the surface. Oil skimmers capitalize on these properties by mechanically removing the oil layer from the fluid surface. This can be done continuously or at predetermined intervals, depending on the design of the skimmer and the requirements of the machining process.

There are several types of oil skimmers utilized in metalworking applications, each with specific advantages suited to different operational environments and fluid volumes. By understanding how these systems work and selecting the appropriate model, CNC shops can significantly enhance their operational efficiency, extend the lifespan of coolants and tools, and ensure compliance with environmental regulations.

Types of Oil Skimmers For Metalworking Facilites

There are several types of oil skimmers used in metalworking applications as listed below:

Type of Skimmer Description Advantages Disadvantages
Belt Skimmer Uses a continuous belt to remove floating oil, can be equipped with depth control ballast. Simple, reliable, effective across various coolant depths. Requires space for belt movement; ballast system adds complexity.
Disc Skimmer Features a rotating disc with oleophilic material; available in horizontal or vertical setups. Compact design, efficient for emulsified oils, works in restricted spaces. May require more maintenance due to mechanical components.
Tube Skimmer Employs a floating tube to attract and collect oil, effective in fluctuating liquid levels. Adaptable to various tank sizes, resistant to chemicals and temperatures. Limited effectiveness for very thick or heavy oils.
Suction Skimmer Uses a suction head to remove oil from the surface, ideal for deep tanks or areas with splashing coolant. Handles heavier oils efficiently, suitable for variable depth conditions. Requires a pump; may not effectively handle light oils.

Each type of skimmer has specific advantages depending on the application, fluid volume, and the nature of the oil being removed. In metalworking machine shops, where space and specific contamination challenges prevail, selecting the right type of skimmer can significantly impact fluid & operational efficiency, contact an EdjeTech engineer today to receive a personal recommendation.

Business Implications of Oil Skimming

From a business perspective, implementing effective oil skimming solutions translates to direct cost savings and efficiency improvements. Cleaner coolants have a longer life, reducing the frequency and volume of coolant replacements. Additionally, minimizing tool wear extends the life of expensive machining tools, thereby reducing operational costs. Efficient oil removal also helps companies comply with stringent environmental regulations, avoiding potential fines and enhancing the company’s reputation for responsible environmental practices.

By understanding the mechanics and benefits of oil skimming, metalworking professionals can make informed decisions about integrating this essential process into their operations.

When Machine Shops Should Use Oil Skimmers

Oil skimmers should be considered essential equipment in CNC fabrication facilities where:

  • Coolant Lifespan is a Concern: Extending the life of coolants can result in significant cost savings. Oil skimmers keep the coolant cleaner for longer periods, reducing the frequency and cost of coolant replacement significantly.
  • High-Quality Machining is Critical: Ensuring that the machining processes are not compromised by poor coolant quality is vital, especially in precision machining operations.
  • Environmental Compliance is Required: Proper oil removal helps meet regulatory standards for waste disposal, preventing potential legal issues and fines.
  • Maintenance and Downtime Reduction: Efficient oil removal systems help reduce the need for frequent cleaning and maintenance, thus minimizing downtime.

What Fluids Benefit Most from Oil Skimming

In CNC machine shops, several fluids can benefit from the use of oil skimmers:

  • Coolants and Cutting Fluids: These are the primary fluids used in the machining process that can be contaminated by tramp oil.
  • Wash Waters: Parts washing systems also accumulate oils that can be effectively removed by skimmers to improve cleaning efficiency and reduce soap consumption.
  • Quenching Fluids: In heat treatment processes within machine shops, oil skimmers can prevent the contamination of quenching fluids, ensuring consistent thermal properties.

Strategic Implementation of Oil Skimmers

To maximize benefits, CNC machine shops should strategically implement oil skimmers:

  • At Source Points: Install skimmers where oil is most likely to accumulate or enter the coolant system, such as near machine tool sumps and central coolant systems.
  • As Part of Regular Maintenance: Incorporate oil skimming into the regular maintenance schedule to prevent buildup and ensure continuous protection.
  • With Adequate Training: Ensure that staff understands the importance of oil skimming and is trained in the operation and maintenance of the skimmers to keep them functioning optimally.

By addressing the need for oil skimmers in metal fabrication workshops specifically, operators can significantly enhance the operational efficiency of their shops. This leads not only to cost savings but also to improved safety and compliance with environmental regulations, ultimately fostering a more productive and sustainable working environment.

Oil Skimmers Suitable for Different Requirements

For metalworking professionals, choosing the right type of oil skimmer is crucial for ensuring efficient operations and maintaining the integrity of machining processes. Each type of oil skimmer has distinct features and advantages, making it suitable for different operational environments and requirements. This section explores more in-depth advantages and disadvantages for the most common types of oil skimmers used in metalworking shops:

Type of Skimmer Suitable for Advantages Disadvantages
Belt Skimmer High-volume oil removal, various tank sizes High efficiency, simple operation Requires space for belt movement
Disc Skimmer Compact spaces, smaller oil loads Compact design, effective on thin oil layers Higher maintenance than belt skimmers
Tube Skimmer Variable coolant levels, larger tanks Flexible installation, chemical resistance Not as effective for thick oils
Suction Skimmer Deep tanks, heavy and thick oils Effective for heavy oils, adaptable to depth Requires a pump, higher operational cost

Suction Skimmers

Suction skimmers use a suction head to remove oil from the surface of the coolant, making them ideal for deeper tanks or areas with splashing coolant. These skimmers are particularly adept at handling heavier oils.

  • Advantages:
    • Handles Heavier Oils Efficiently: Especially effective in removing dense, heavy oils from deep or turbulent coolant systems.
    • Suitable for Variable Depth Conditions: Works well in environments where the coolant level fluctuates significantly.
  • Disadvantages:
    • Requires a Pump: Dependency on a pump for operation can introduce additional maintenance and energy costs.
    • May Not Handle Light Oils Effectively: Lighter oils might not be removed as efficiently due to their lower density and viscosity.
  • Applications: Best for environments where coolant tanks are deep or have significant agitation, and where the oil has a higher viscosity.

Belt Skimmers

Belt skimmers utilize a looped belt made from materials that attract oil. The belt passes through the surface of the coolant where it picks up oil and then moves through a set of wiper blades that scrape the accumulated oil off the belt and into a collection container.

  • Advantages:
    • High Efficiency: Belt skimmers are particularly effective at removing large volumes of oil quickly.
    • Simple Operation: They are easy to install and operate, requiring minimal maintenance.
    • Versatility: Belt skimmers can be used in tanks of varying sizes and are effective even in shallow fluids.
  • Applications: Ideal for CNC shops with high levels of oil contamination and those that require frequent and quick removal of oil to maintain coolant effectiveness.

Disc Skimmers

Disc skimmers feature a rotating disc that skims the surface of the coolant. The disc, coated with a material that has a high affinity for oils, dips partially into the coolant, allowing the surface oil to adhere to it. As the disc rotates, the oil is carried to a wiper blade that scrapes the oil off the disc into a collection container.

  • Advantages:
    • Compact Design: Disc skimmers are compact and can be easily installed in restricted spaces.
    • Selective Skimming: They are highly effective at removing thin layers of oil, making them suitable for applications where oil layers are minimal.
    • Low Maintenance: Disc skimmers require less maintenance compared to other types due to fewer moving parts.
  • Applications: Best for smaller CNC shops or individual machines that periodically produce smaller quantities of tramp oil.

Tube Skimmers

Tube skimmers use a floating plastic or stainless steel tube that rotates on the surface of the coolant. The tube attracts the oil, which adheres to it, and as the tube passes through a scraper, the oil is removed and directed into a collection container.

  • Advantages:
    • Effective in Varied Conditions: Tube skimmers can operate effectively in fluctuating liquid levels and in areas with floating debris.
    • Ease of Installation: They can be easily adapted to different tank sizes and configurations.
    • Durability: The materials used in tube skimmers are often resistant to a variety of chemicals and temperatures.
  • Applications: Suitable for machine shops with variable coolant levels or those requiring a durable, adaptable solution for continuous oil removal.

Choosing the Right Oil Skimmer

Selecting the appropriate oil skimmer for your operations is a crucial decision that impacts not only the efficiency and lifespan of the machining operations but also the overall environmental footprint of the facility. The right skimmer optimizes coolant performance, extends tool life, and ensures compliance with environmental standards. Here’s a guide to help you choose the most effective oil skimmer for your specific needs.

Assess Your Needs

Before selecting an oil skimmer, it’s important to assess your shop’s specific requirements:

  • Volume of Oil: Estimate the amount of oil typically generated in your operations. This helps determine the capacity of the skimmer needed.
  • Type of Coolants Used: Different coolants may react differently with tramp oil, affecting the choice of skimmer.
  • Space Constraints: Consider the physical space available for installing the skimmer. Some skimmers require more room than others.
  • Budget: Balance the initial investment against potential savings in coolant costs and maintenance.

Consider Operational Efficiency

  • Ease of Maintenance: Choose a skimmer that is easy to maintain. Frequent downtime for maintenance can negate the benefits of using a skimmer.
  • Energy Consumption: Consider the energy efficiency of the skimmer, as this will impact operational costs over its lifespan.
  • Durability: The skimmer should be durable enough to handle the specific conditions of your shop, including exposure to chemicals and varying temperatures.

Installation Requirements

  • Integration with Existing Systems: Some skimmers can be easily integrated with existing coolant systems, while others might require significant modifications.
  • Installation Space: Ensure that the skimmer fits within the allocated space without disrupting other operations.

Environmental and Regulatory Considerations

  • Compliance: Ensure that the skimmer meets local environmental regulations concerning waste disposal and management.
  • Waste Handling: Consider how the skimmer handles collected oil. Some systems facilitate easier recycling or disposal of waste oil, which can be a significant advantage.

Making the Decision

Once you’ve considered all these factors, it’s important to weigh the pros and cons of each option within the context of your specific operational needs.

Contact a filtration engineer at EdjeTech to gain insights based on experience with similar setups in the industry.

Each type of skimmer offers unique benefits, and the choice will depend on the specific needs of the facility, including the volume of oil to be removed, space constraints, and maintenance capabilities. By carefully assessing these factors, shop managers can ensure they select the most effective and efficient oil skimming solution.

Understanding Tramp Oil in Machining Facilities

Tramp oil in metalworking is a prevalent issue that can compromise the quality of machining processes, degrade the working environment, and increase operational costs. Understanding the sources, impacts, and management of tramp oil is crucial for maintaining efficient operations and extending the life of both machinery and machining fluids.

Sources of Tramp Oil

Tramp oil primarily originates from a few common sources within metalworking facilities:

  • Leaking Equipment: Oils used for lubricating machine components such as hydraulic systems, gearboxes, and spindles can leak and accumulate in the coolant.
  • New Additions: Fresh oils added to machines for maintenance or lubrication purposes can inadvertently mix with coolants.
  • External Contamination: Oil can also enter coolant systems from external sources, including the introduction of new parts or materials that have been coated in protective oils.

Understanding these sources is the first step in effectively managing and reducing the presence of tramp oil in CNC operations.

Impact of Tramp Oil on CNC Operations

The presence of tramp oil in coolant systems can lead to several detrimental effects:

  • Reduced Coolant Efficiency: Oil layers on the coolant surface impede heat dissipation, reducing the coolant's ability to effectively control temperature during machining processes.
  • Tool Wear and Damage: Increased thermal loads and reduced lubrication properties of contaminated coolants can accelerate wear on cutting tools and reduce their operational life.
  • Product Quality Issues: Surface finishes on machined parts can be adversely affected by poor coolant conditions, leading to increased scrap rates and rework.
  • Health and Safety Risks: Tramp oil can lead to the growth of harmful bacteria and fungi in coolant tanks, creating health risks for workers. It also increases the risk of slips and falls due to oil spills on shop floors.

Managing Tramp Oil

Effective management of tramp oil is essential for optimizing CNC operations:

  • Regular Monitoring: Implementing a routine schedule for checking coolant conditions and tramp oil levels helps in early detection and management.
  • Use of Oil Skimmers: Installing appropriate oil skimmers can continuously remove tramp oil, maintaining the integrity and efficiency of the coolant.
  • Proper Maintenance Practices: Regularly maintaining and repairing machinery to prevent leaks, and using absorbents or separators in areas prone to oil spills, can minimize tramp oil introduction.

Benefits of Effective Tramp Oil Management

  • Extended Coolant Life: By removing tramp oil, the coolant's effective life is extended, reducing both coolant costs and disposal fees.
  • Improved Machine Performance: Clean coolant ensures optimal cooling and lubrication, which enhances machine performance and extends the life of the equipment.
  • Enhanced Product Quality: Consistent coolant quality helps maintain high standards in product finish, reducing waste and improving customer satisfaction.
  • Safer and Healthier Work Environment: Reducing tramp oil helps prevent the buildup of bacteria and reduces the risk of accidents, creating a safer and healthier workplace.

Strategies for Optimal Tramp Oil Removal

To maximize the effectiveness of tramp oil removal in machining operations, consider the following strategies:

  • Selection of Suitable Oil Skimmers: Choose skimmers that are best suited to the specific type and volume of tramp oil typically encountered in the shop.
  • Integration with Other Coolant Maintenance Practices: Combine oil skimming with filtration systems and regular coolant treatment practices to comprehensively manage coolant quality.
  • Employee Training: Ensure that all machine operators and maintenance personnel are trained on the importance of managing tramp oil and the practices required to minimize its impact.

Understanding and managing tramp oil effectively is critical for maintaining the efficiency, safety, and profitability of CNC machining facilities. By implementing robust management practices and utilizing effective oil removal technologies, shops can protect their equipment, maintain high-quality outputs, and ensure a safe working environment.

Additional Tools and Accessories

While oil skimmers are critical in managing and removing tramp oil in from coolants, several additional tools and accessories can enhance their performance, efficiency, and the overall coolant management system. Integrating these supplementary products can further optimize operational processes, extend coolant life, and improve machine performance. Here’s an overview of essential tools and accessories that complement oil skimmers in the fluid waste filtration and recycling stream.


A decanter is a valuable accessory for oil skimmers that helps separate any residual water from the collected oil. This separation is crucial for minimizing waste and reducing the volume of waste oil that needs to be disposed of or recycled.

  • Benefits:
    • Cost Efficiency: Reduces the amount of coolant that is lost with disposed oil, lowering the frequency and volume of coolant replacement.
    • Environmental Impact: Minimizes the volume of waste, thus reducing disposal costs and environmental footprint.

Oil Water Separators

Oil water separators are critical in facilities that handle large volumes of oil and water mixtures. They work by allowing oils to separate from water due to gravity, which is effective in removing large quantities of oil before it enters the coolant system.

  • Benefits:
    • Improved Skimmer Efficiency: By reducing the oil load on the skimmer, separators ensure that skimmers can operate more efficiently.
    • Extended Coolant Life: Helps maintain the quality of coolant by preemptively removing large oil volumes.

Coolant Recycling Systems

Integrating a coolant filtration system can be a game-changer for CNC shops looking to maximize the reuse of their coolants. These systems filter and treat contaminated coolant so that it can be reused, reducing the need for fresh coolant.

  • Benefits:
    • Cost Savings: Significant reduction in coolant purchase costs and waste disposal costs.
    • Reduced Waste: Lowers the environmental impact by decreasing the amount of hazardous waste generated.

Skimmer Mounting Systems

Proper installation of oil skimmers is crucial for their effective operation. Pre-fabricated mounting systems provide a secure and optimized setup for skimmers, ensuring they are positioned correctly for maximum oil removal.

  • Benefits:
    • Easy Access and Maintenance: Enhances the accessibility of skimmers for maintenance and adjustments.
    • Optimal Placement: Ensures that skimmers are installed at the most effective location on the coolant tank.

Temperature Control Systems

In shops that operate in varying temperature conditions, maintaining a consistent temperature can be crucial for effective oil skimming. Accessories like heaters or chillers can be attached to skimmers to regulate the temperature of the oil and coolant, enhancing the efficiency of oil removal.

  • Benefits:
    • Consistent Performance: Ensures skimmers can operate effectively regardless of external temperature fluctuations.
    • Enhanced Oil Viscosity Management: Helps maintain the oil at optimal viscosity for easier removal.

Automated Monitoring Systems

Automated systems can monitor the performance of oil skimmers and other coolant maintenance equipment, providing real-time data on efficiency and alerting staff to issues before they become critical.

  • Benefits:
    • Increased Uptime: Prevents breakdowns and reduces downtime through proactive maintenance.
    • Data-Driven Decisions: Allows for better operational planning and efficiency improvements based on performance data.

By incorporating these tools and accessories, operators can enhance the functionality of their oil skimmers, ensuring a more comprehensive and efficient coolant management system. These investments not only improve the immediate working environment but also contribute to long-term savings and sustainability goals.

Optimize Your Coolant Management Today

Implementing effective tramp oil skimmers is crucial for enhancing the efficiency and longevity of machine shops and metalworking operations. This guide has outlined the selection and benefits of various oil skimming systems, emphasizing their role in improving machine performance, extending coolant life, and ensuring a cleaner work environment. Effective tramp oil management not only reduces operational costs but also boosts productivity and ensures environmental compliance.

Reach out to EdjeTech today to schedule a personalized consultation today and discover the transformative impact a tailored coolant management solution can have on your metalworking facility.

Reduce Waste, Increase Production & Profit Margins

For over 38 years, EdjeTech Services has been at the forefront of industrial fluid management, specializing in advanced coolant filtration systems and expertise extending to both oil-based and water-based fluids.

Committed to reducing operational expenses, our tailored solutions across various industries are designed to maximize efficiency and ensure a significant return on investment for our clients.

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