Mirka DEROS II 650CV Random orbital sander
The Mirka DEROS II 650CV is a professional-grade direct electric random orbital sander designed and manufactured by Mirka Ltd of Finland. The model designation indicates its 150-millimeter (6-inch) backing pad diameter, with the "650" denoting the combination of pad size and orbit configuration, while "CV" refers to its central vacuum dust extraction system.
Developed for effective and dust-free sanding of all kinds of surfaces, the DEROS II 650CV features a 5.0-millimeter oscillation orbit, which provides a balance between material removal and surface finish quality. The tool is powered by a 400-watt brushless motor operating on 220-240 volt alternating current, and weighs approximately 1.1 kilograms.
As the second generation of Mirka's DEROS line, the DEROS II represents numerous improvements over its predecessor, including increased motor power and enhanced user interface features. The sander is primarily used by professionals in construction, automotive refinishing, woodworking, and marine industries, though its design has also attracted serious hobbyists willing to invest in premium equipment.
Technical Specifications
Power and Motor
The DEROS II 650CV is equipped with a 400-watt brushless motor that operates on a 220-240 volt AC power supply with a UK plug configuration. The brushless motor design provides several advantages over traditional brushed motors, including longer operational life and the ability to maintain consistent speed under heavy load. This represents a 50-watt increase in power compared to the previous generation DEROS model, which utilized a 350-watt motor.
Operating Parameters
The sander features variable speed control ranging from 4,000 to 10,000 revolutions per minute, adjustable via an easy-to-operate lever positioned on the top of the unit. The speed settings are indicated by clearly visible LED indicators that provide immediate visual feedback to the operator.
Physical Characteristics
The tool weighs 1.1 kilograms and features a low-profile design with a height of only 10 centimeters. The backing pad measures 150 millimeters in diameter and operates with a 5.0-millimeter orbit pattern. This orbit size is considered the most commonly used configuration and achieves a good balance between stock removal and surface finish.
Noise and Vibration Levels
Acoustic measurements indicate a sound pressure level of 71.0 decibels (LpA), with a sound power level of 82 decibels (LwA) and a measurement uncertainty of 3.0 decibels. The vibration emission value is 3.4 meters per second squared, with an uncertainty factor of 1.5 meters per second squared. These relatively low vibration values contribute to reduced operator fatigue during extended use.
Connectivity and Monitoring
The DEROS II 650CV incorporates Bluetooth connectivity that enables integration with Mirka's myMirka mobile application. This connection facilitates real-time vibration monitoring and tracking of operational metrics, allowing users to maintain compliance with health and safety regulations regarding hand-arm vibration exposure.
Dust Extraction
The unit is designated as central vacuum ready, meaning it is designed to connect directly to a dust extraction system via a 27-millimeter hose. The backing pad features a multi-hole design that facilitates efficient dust removal when used in conjunction with compatible mesh abrasives such as Mirka's Abranet product line.
Key Features
Ergonomic Design
The DEROS II 650CV features a unique symmetrical design that enables ambidextrous operation, allowing both left-handed and right-handed users to operate the tool comfortably. The compact, low-profile construction facilitates access to confined spaces and reduces strain during overhead work. The tool's balanced weight distribution, combined with its low noise level and low vibration values, allows it to be used for long periods without fatigue.
Control System
The DEROS II incorporates a redesigned control interface that improves upon the original model. A separate on/off switch controls power to the unit, while a dedicated lever mechanism positioned under the operator's hand adjusts the sanding speed. The speed selection is communicated through clearly visible LED indicators that display the current RPM setting, eliminating guesswork during operation.
Motor Technology
The high-efficiency brushless motor maintains a consistent speed even when subjected to heavy pressure or working with demanding materials. Brushless motors eliminate the need for carbon brush replacement, reducing maintenance requirements and extending the operational lifespan of the tool. The motor's design also contributes to the reduced vibration levels characteristic of the DEROS II series.
Dust Management
As part of Mirka's dust-free sanding solution, the DEROS II enables efficient dust-free sanding when connected to an appropriate vacuum extraction system. The central vacuum configuration routes dust directly through the backing pad's multi-hole pattern, which aligns with similarly perforated abrasive discs. This system significantly reduces airborne particulate matter, creating a healthier and safer working environment by minimizing operator exposure to potentially harmful dust.
Pad Attachment System
The sander utilizes a hook and loop (Velcro-style) attachment system for securing abrasive discs to the backing pad. This quick-change mechanism allows operators to swap between different grit levels rapidly without requiring tools. The backing pad itself can be replaced using a provided wrench, and Mirka offers backing pads in different densities to suit various applications—the tool ships with a medium-density pad as standard.
Integrated Safety Features
An integrated vibration sensor monitors the tool's operation and communicates data to the myMirka application via Bluetooth. This feature assists users in maintaining compliance with workplace health and safety regulations concerning hand-arm vibration syndrome (HAVS), a serious occupational health concern for workers who regularly use vibrating power tools.
Power Cable
The unit includes a 4.3-meter rewireable mains cable with a UK plug configuration. The rewireable design allows for field replacement of the plug or cable without requiring specialized service, and the cable features a locking mechanism that prevents accidental disconnection during use.
Applications and Industries
General Purpose Sanding
The 5.0-millimeter oscillation is suitable for general purpose sanding, representing the most commonly used orbit configuration across various applications. This orbit size strikes a balance between material removal efficiency and surface finish quality, making it versatile enough for multiple stages of surface preparation work.
Woodworking
In woodworking applications, the DEROS II 650CV handles tasks ranging from initial stock removal after planing to final finish sanding before coating application. The 150-millimeter pad size provides efficient coverage on flat surfaces such as tabletops, cabinet doors, and panel work, while the 5.0-millimeter orbit produces a scratch pattern that can be refined with progressively finer abrasive grits. The dust extraction capability is particularly valued in woodworking environments, where fine wood dust poses both health hazards and fire risks.
Automotive Refinishing
The tool finds extensive use in collision repair and automotive bodywork applications. In this context, it is employed for sanding body filler, feathering paint edges, preparing surfaces for primer and paint, and refining clearcoat finishes. The low vibration characteristics reduce the risk of creating uneven surfaces or distorting thin sheet metal panels. Professional automotive refinishers value the tool's ability to work efficiently on both metal and plastic substrates commonly found in modern vehicle construction.
Construction and Decoration
Construction and decorating professionals use the DEROS II 650CV for preparing drywall surfaces, smoothing joint compound, sanding primers and paints, and refinishing woodwork such as doors, trim, and staircases. The dust extraction capability is especially important in occupied buildings where minimizing mess and airborne particulates is essential. The tool's light weight reduces fatigue during overhead work such as ceiling preparation.
Marine Applications
In marine environments, the sander is used for preparing and refinishing fiberglass hulls, decks, and interior joinery. The ability to work effectively on curved surfaces, combined with efficient dust extraction, makes it suitable for the confined spaces typical of boat interiors. However, users must take precautions to protect the tool from moisture and salt exposure, as the electrical components and motor are not designed for wet conditions.
Professional Versus Hobbyist Use
While the DEROS II 650CV is primarily designed for professional users, its features have attracted serious hobbyists and home workshop enthusiasts. Professional users justify the tool's premium price through daily use, reduced downtime, and the ability to work more efficiently. Hobbyist woodworkers and automotive enthusiasts may find value in the tool's superior ergonomics and dust control, particularly for larger projects that would otherwise require extensive use of less sophisticated equipment.