What Is a Random Orbital Sander? All You Need To Know

If you’re looking for a sander for your woodworking or other DIY projects, you may get many recommendations for a random orbital sander. You may have an idea of what it’s supposed to do, but what exactly is a random orbital sander, and what makes it different from other sanders?

A random orbital sander is a tool that sands in irregular circular motions. It uses a sandpaper disc that spins and moves in ellipses simultaneously, creating a finer finish. You can use random orbital sanders to build and clean different objects made of wood, metal, and other materials. 

If you want to learn more about orbital sanders and how they work, read the rest of this article. I will delve into details about how this tool works and where it can be used, but I will also explain how to use it and what to look for when buying it.

Random Orbital Sander Definition

A random orbital sander is a handheld tool used to sand wood and other materials in woodworking. Unlike a standard orbital sander, a random orbital sander can move the sanding disc in irregular overlapping ellipses while it’s spinning on its axis. This extra motion creates a much finer finish with no swirls left, no matter what the direction of the grain is. 

You can save a lot of time using a random orbital sander to finish furniture, but if you want to remove a certain amount of material from an object, it’s better to find another, more aggressive sander. The random orbital sander is probably one of the most popular power tools in woodworking. It makes it easy to create a fine finish on wood or metal with little effort and time.

Electric vs. Pneumatic Random Orbital Sanders

Random orbital sanders can be electric or pneumatic. As you might have guessed, the main difference is how they are powered. However, there are other differences between them that can convince you to go one way or the other. Here’s a table to illustrate the differences:

Electric Random Orbital SanderPneumatic Random Orbital Sander
Uses electric powerUses air pressure
Convenient on the go (wherever you can find an outlet)Convenient in one place 
Requires less maintenance.Requires more maintenance (lubricating, maintaining air filter)
Higher cost upfront, but lower in the long run.Lower cost upfront, but additional expenses because of maintenance.

Based on the above differences, you can decide what type of random orbital sander you want to use.

Random Orbital Sander Parts

It’s helpful to know all the different parts of a random orbital sander so that you know how to use it properly and understand what is wrong if the sander is not working.

  • Body. The body of the sander holds the motor that makes the device work and sometimes serves as a handle in itself. The power switch is located on the body.
  • Grip. The correct way to hold a random orbital sander is to put it in the palm of your hand using the so-called palm grip located at the top part of the sander.
  • Sanding Pad. The sanding pad is the part that rotates around its axis and at the same time moves in elliptical motions. This is where the sanding disc is placed.
  • Battery/Power Cable. Depending on the source that powers the sander, you will see the battery, which is rechargeable and can be replaced, or the power cord that connects your sander to a power outlet.
  • Lip Seal. This part is made of rubber and is placed between the sanding pad and the body, isolating the internal part of the sander from the debris that it creates to avoid malfunctions.

Most random orbital sanders have dust bags, which gather all the particles of wood, metal, and other materials discarded by the sander. Additionally, some may have a D-handle, which is a handle at the bottom of the sander that is used for a more controlled grip.

How Do Orbital Sanders Work? 

As their name suggests, orbital sanders move in circles to sand objects or materials. The goal of these tools is to create friction in order to remove particles of the material to remove the external layer. 

Orbital sanders use replaceable sanding sheets made of an abrasive material, usually sandpaper. These sheets are attached to a pad that rotates in circles to sand the surface of an object. There are several levels of speed that you can select based on the material and the kind of finish you want.

Random orbital sanders, like standard ones, use the same principle but with an added twist. They use special sanding discs instead of just sheets of sandpaper, and, as I mentioned above, the pad rotates and spins on itself

The pad of the random orbital sander is connected to a ball-bearing mechanism that allows the pad to move in random ellipses, ensuring that the sanding disc doesn’t perform the same trajectory twice. This provides a finer job with no swirls on the surface. Additionally, because it is more powerful, the random orbital sander can work very well, even across the grain of wood. 

What Is an Orbital Sander Used For?

An orbital sander is useful in different ways around your house, including restoring hardwood floors, finishing or building furniture, or building staircases. Additionally, you can use an orbital sander for objects made of materials other than wood.

Let’s see some of these uses:

  • Restoring hardwood floors. Orbital sanders are practically made for this; they can help smooth and clean your hardwood floors, producing an immaculate finish.
  • Finishing furniture. You can use an orbital sander to finish something you’re building from scratch or clean the surface of an existing piece of furniture to which you want to apply paint or stain.
  • Building or restoring staircases. Building a staircase requires a lot of precision and a perfectly smooth finish, so using an orbital sander would ensure you get the best results.
  • Building multiple-component furniture. If you like building more complicated pieces of furniture such as cupboards, closets, or chests of drawers, the orbital sander is great for smoothing out any imperfections that would cause the furniture not to work well.

In addition to the above ways, you can also use the orbital sander for non-wood materials, especially on smaller scales. You can easily finish objects made of metal or plastic. Moreover, the orbital sander can be used to remove unwanted layers, like old paint or rust. 

Because the random orbital sander is just an advanced version of the standard orbital sander, it is safe to assume that it can be used in all the above ways. It may even get the job done faster and more efficiently. You can use the random orbital sander to finish all kinds of objects and surfaces made of wood.

You can also use the random orbital sander to finish surfaces made of other materials. You can finish or clean metal surfaces or objects with ease. Additionally, you can use the random orbital sander on objects made of composite materials like concrete. 

How To Use a Random Orbital Sander

A random orbital sander is pretty easy to use, but it still requires caution and knowledge of how it works to be safe and efficient at the same time. There are a few steps that you need to follow in order to use your random orbital sander:

Before You Start

Before you think about sanding, you must ensure that you have all the necessary equipment and protective gear to be safe. Just because there are no dangerous sharp edges involved doesn’t mean you can’t get hurt.

All the sawdust or other small particles that are produced as a result of the sanding process can end up in your eyes or your respiratory system if you’re not careful. Wear protective goggles and a mask to ensure this doesn’t happen. It’s also important to make sure that your shop or the area where you’re working is open and well-ventilated.

Additionally, you may want to have a vacuum cleaner nearby. Whether your orbital sander has a dust collecting system or not, there will be debris and dust wherever you work, so keep a vacuum cleaner nearby to quickly clear the area for you.

1. Attach the Disc to the Sanding Pad

The first thing to do is choose what sanding grit you will use. You should base this decision on the type of surface you want and the kind of job that the sander should do. For instance, if you wish just to remove the paint off a surface, you should use a coarse disc of 20 to 40 grit. If you want a smoother finish, increase the grit and choose smoother discs.

There are two different attaching methods that you can use on your random orbital sander. Some can be stuck to the pad by peeling the paper off the disc and then placing it on it. Others have a hook-and-loop system that allows you to attach the disc to the pad like velcro, like the S SATC 72-Piece Sanding Discs Set (available on Amazon.com). These are higher-quality sanding discs that can be found online at an affordable price.

Whatever disc you choose, attach it carefully to the pad, ensuring the position of the holes on the disc matches one of the dust collection holes on the pad. If your random orbital sander doesn’t have a dust collecting system, you don’t have to worry about this.

2. Make Sure the Surface Doesn’t Move

Unless you’re working on your hardwood floor, you’re going to need to secure the object that you want to sand so that it doesn’t move while you’re working. The object should be put somewhere high enough for you to be comfortable while working and secured so that it doesn’t move even if you apply pressure on it.

3. Set the Speed

There’s usually a speed control on your random orbital sander that gives you different option speeds. Naturally, you might think the faster, the better, but this is not always the case. When dealing with delicate furniture with thin coats, you don’t want to ruin them by sanding them at super high speed. If you don’t have this option, skip to the next step.

4. Test Your Random Orbital Sander

It’s recommended that you test your sander on a wood block before you start properly sanding an object. This is to determine if you will begin sanding by placing the sander on the surface and then turning it on, or start by keeping the sander in the air, turning it on, and then softly placing it on the surface. 

By testing the sander on a block of wood, you get an idea of what your sander will do once it starts, and you start the right way with the desired object. This is useful, especially if you’re using your sander for the first time.

5. Start Sanding

Turn the sander on and start moving it across the material with a firm grip. The movement should be evenly paced, side to side. Remember to keep moving across the whole surface in order to sand on the same level everywhere. If you dwell on a particular area, you risk removing extra layers and creating an uneven surface.

It’s also important to apply the same level of pressure everywhere and not to tilt your sander at any point to avoid making marks or divots. Keep an eye on the surface to ensure the sander is doing what it’s supposed to. 

Once satisfied with the flat surface, you can start with the edges. However, you should lift the sander off the surface before continuing on to the edges so you don’t damage them. Place the random orbital sander back on the edge, making sure the edge is at the center of the disc, and move carefully, using both hands.

6. Finish Sanding and Clean Up 

Once you’re satisfied with how the surface and the edges look, you can turn off the sander. Most professionals lift it off the surface before turning it off. After turning your sander off, all you need to do is take the vacuum cleaner to remove the dust and debris.

After you clean the dust, check your work to see if it needs extra sanding. If it does, you can start again; if not, unplug the sander, clean it, and remove it. It’s recommended to wipe the surface with a clean cloth to get it ready for the next step.

Aspects To Look for in a Random Orbital Sander

If you’re looking to buy an orbital sander, you need to look at all the different aspects and see what combination works better for you. This combination needs to be suitable for wherever you’re working or what you’re planning to sand in the future. Some aspects to consider are:

  • Pad size. If you’re planning on sanding large surfaces, a larger pad can finish the job more quickly.
  • Motor size. If you have a shop and work on different surfaces of varying roughness and materials, you might want to pick a bigger size.
  • Features. There are different sanders with a few optional features, but if you can, opt for a random orbital sander with a dust collector.
  • Cost. Random orbital sander prices vary from $50 to $500. A good option for beginners is the Ridgid R2601 5-Inch Random Orbit Sander (available on Amazon.com). 


Random orbital sanders are great tools to help you finish or clean a surface. Their effectiveness results from an abrasive disc that not only rotates in circular motions but also spins on itself. Random orbital sanders can be used on wood, plastic, metal, or compound materials.

To use an orbital sander, prepare your workstation and protective gear first, then test your sander. Afterward, you can start sanding by moving evenly and continuously across the surface, leaving the edges for last. After finishing, vacuum and wipe the surface.

Damien Madeira

Damien has been doing woodworking for the last 5 years. He began as a hobbyist with hand tools and slowly worked his way up to own larger machines and mill rough wood into beautiful creations. While still considering himself a hobbyist, he has a passion for woodworking and enjoys working with epoxy as well.

Recent Posts