DA Sander-What is it and How does It Work

Asking the question, “What is a dual action sander?” is valid because there are many types of sanders on the market. Finding the correct sander for your next project can be difficult because each sander is designed for specific sanding tasks. One of the standout features of a DA sander is that it can sand and buff simultaneously which is a real time saver. In this article, we will take a closer look at direct action sanders and explain how they are used to help you make informed decisions.

What Is A DA Sander 

DA Sander

So, what is a DA sander? The easiest way to explain what the DA sander is and how it works is to consider that it’s based on two other types of sanders, the disk and belt sander. Let’s take a look at each in turn for those that are unfamiliar with how they operate.

The Disk Sander:

This is a handheld tool that uses a disc of sandpaper attached to a motor driven wheel. The disk spins at high speeds to smooth uneven materials with contact at the disk edge. Certain models have significant lateral movement that prevents the sanding disk from penetrating into the work surface. But, there is a significant risk that scratches across the grain of the wood can be made during the sanding process.

The Belt Sander:

This can be a handheld or stationary sander, but for our purposes we will consider the handheld variant here. The sanding belt is designed to move at high speeds to remove a lot of material in a very short space of time. This can be useful if you need to remove a number of high bumps on a flat work surface. But, belt sanders can be too powerful for many applications, they may remove too much at once and they can create scratches if they are not used carefully.

The DA Sander:

A dual action sander combines the best features of the disk and belt sanders. The sanding pad moves in forward and backward motion like a belt sand. But, there is a slight wobble like the rotation of a disk sander. The sanding movement is primarily a circular motion, but it’s also a random orbital movement. The DA sander can vary depending on the make and model. Some spin more like a disk sander and others have a semi-rotary movement where the sandpaper doesn’t turn.

How does a DA sander work?

DA sanders have two modes of operation, the first locks the pad into a spinning motion along a flat plane. The second moves the sanding pad with internal bearings to create that slight wobble that prevents the buildup of excess friction. This dual-action flexibility gives you more options when sanding because the locked rotator removes a lot of material quickly and the orbital motion can create smoother finishes.

The DA sander spins the sanding disc using a gear system connected to the motor. This allows the user to cover large surfaces quickly without dwelling on areas where over sanding can occur. With some practice, it is possible to get a better overall finish and save time. Most dual-action sanders can be switched from a sanding to a buffing action with a one-click button.

The 7 Benefits Of Having A DA Sander 

  1. A smoother overall finish.
  2. The bigger motors are powerful for longer sanding projects.
  3. Finishing the project faster reduces hand fatigue.
  4. The hook and loop sanding discs are easy to change.
  5. Large volumes of material can be removed quickly.
  6. The dust collection systems are superior to disk and belt sanders.
  7. Many modern DA sanders have variable speeds to improve control.

The 6 Negatives Of Having A DA Sander 

  1. Sanding with circular pads is not possible in tight spaces and corners.
  2. Damaged sanding pads degrade the sanding quality.
  3. The hook and loop on the sanding pad will not hold the disk if it’s dirty.
  4. The aggressive nature of DA sanders can damage the work-piece.
  5. The sanding disks can be hard to source locally.
  6. DA sanders are more expensive than disk or belt alternatives.

Also Check: 6 Best Sanders For Removing Paint From Wood & Deck

What To Consider Before Buying A DA Sander

We hope that we’ve answered some of the broader aspects of the “What is a dual action sander?” question. But, when you shop for a DA sander, there are six key features that you need to consider before you make a final purchase:

1.    Variable Speed

Some DA sanders have a single speed setting, but the better models have variable speed settings that can tame the aggressiveness of the sander. The higher speeds are ideal when you need to grind down a surface quickly. The lower speeds are better for finer sanding tasks when you want a smooth finish.

Most power tools use revolutions per minute (rpm) as a measure of speed but DA sanders use oscillations per minute (opm). The main distinction is that a dual-action sander has an oval sanding path rather than a circular motion. The lack of a variable speed feature can be offset if you choose the correct sandpaper grit for the task at hand. This would be a coarse grit for material removal, medium grit for smoothing tasks and a fine grit to get the perfect finish.

2.    Three Ways to Power a DA Sander

Corded: Simply plug the DA sander into a power outlet and you’re ready to start sanding. There is no battery to recharge, but the limitation is that you cannot move too far from the power supply.

Cordless: As the name suggests, these are great power tools when you need to work away from a power source. There is no need for an extension cord and you get 30-45 minutes of sanding with each charge. For this reason many people have one or two batteries on hand to continue the work when the first battery fully discharges.

Pneumatic: The power source is compressed air which is an ideal choice for woodworkers that use a compressor to power air tools. The smaller pancake style compressors don’t have sufficient power to run a DA sander for long. For the best results an air compressor with a minimum air volume of 40 cfm (cubic feet per minute) should be used.

3.    Disk Size

Dual action sander

DA sanders have standard 5” diameter and generic sandpaper disks can be found in this size at home improvement or hardware stores. There are models with smaller disks that range from 1” up to 4” in diameter which are ideal if you need to sand in tight spaces.

There are larger disk sizes that start at 6” in diameter which are a good option for large scale sanding projects. The sandpaper disks that you can use may vary depending on the dual-action sander you choose and some may be brand specific.

4.     Weight

The average weight of a dual-action sander is 2-4 lbs and the smaller models can weigh only 1.5 lbs. The larger and more powerful models can weigh 7 lbs or more and the weight of the sander should be factored into your choices. A lighter sander will create less wrist and hand fatigue when you work on a vertical surface.

5.    The Dust Collection System

Some DA sander models have detachable dust bags to collect the wood dust as you sand the surface. There may be other attachments that can connect the DA sander to a wet/dry vacuum hose. Some dust will always escape and it’s important to wear a dust mask when you’re sanding. But, a good dust collection system can save you a lot of clean up time when you’re sanding and this is especially true if you work outdoors.

6.    An Extra Handle

Some DA sanders have a top mounted palm grip handle that improves the maneuverability when sanding one-handed. There may be an extra side grip that is helpful if you need fine control when you’re sanding with two hands. Some polishers and sanders even have a barrel grip that further improves the control and leverage when your hands are closer to the work surface.

What Are The 4 Types Of DA Sanders? 

1.    The Palm Sander

This is a smaller dual-action sander for sanding drywall patches, stripping furniture and other areas. Palm sanders are inexpensive, they derive their sanding power from fast revolutions and they are light. These sanders can be used with a neck or over the top grip as required.

2.    An In-Line Drive

This is a good option when you need to perform extensive sanding tasks and you don’t want to wield a larger right-angle drive model. The motor is situated directly above the sanding pad which makes this a good alternative to palm and more powerful sanders. People with smaller hands can grasp the front and rear mounted handles easily and there is no need to hold the body of the sander.

3.    The Right-Angle Drive

When you need a DA sander that can work all day and every day with no overheating issues this may be the ideal model type. The barrel shaped body has a powerful motor in the 3-5 up to 5 amp range with a slow and cooler 5,000 opm. The best models have improved gears and precision bearings to lower the vibrations and improve longevity.

4.    Detail Sanders

This is not a true DA sander, but it’s likely that you will want or need one to complement those tools. A detail sander has a triangular sanding pad that can fit in tight spaces and corners to complete your projects. The best examples have flush-cutting saws, scraper blades and other accessories that make this sander a versatile tool.

Reasons Why I Would Need To Purchase A DA Sander

DA sanders are easy to control and they don’t leave scratches. There are five common applications that these sanders are ideally suited for:

  1. The sanding of multiple work pieces with different grain directions at the same time.
  2. Auto body repair to remove old paint layers before a respray.
  3. Smooth sanded surfaces on intricate woodwork projects
  4. Smoothing surfaces without leaving scratch marks.
  5. Creating smooth visible surfaces to improve the outward appearance.


We hope that we have answered the “What is a dual action sander?” to your satisfaction. The DA sander is a useful and flexible tool that can be found in many amateur and pro workshops. This tool replaces the disk and belt sander, but you may need a detail sander to sand those hard to reach areas.