What Is A Random Orbital Sander?

best-random-orbital-sanderA Random orbital sander is a small power tool, used by many people and due to its popularity will be found in workshops, garages and sheds throughout the land.

Mainly it is used by people who work with wood, including carpenters, framers, furniture makers, the construction industry and those who like to do their own Home Projects.

Their main purpose is to smooth out the rough surfaces and edges of wooden, metal or plastic materials. Primarily though they are used for most types of woodworking.

When working on certain projects that involve the use of wood, at some stage you will want your work to be left with a nice smooth finish. This is referred to in the trade as sanding and finishing.

This can be done manually with sandpaper, but it is slow and painstaking work. (If you have ever tried it, you know what I mean) There are two main things to consider which is the overall stock removal and the finishing stages.

Electrical Sanders

A random orbital sander helps take the hard work out of doing projects like these. You simply attach some sanding discs (or sandpaper) to the sander, and allow the power tool to do the work for you.

Orbit sanders use small pads or disks. A motor inside then moves these in a spinning and jittering (oval) motion which creates a random pattern. They get the name random as they create a mark-free, well finished and very smooth surface.

The random movement that this creates means that the grit is not constantly moving on the same piece of the wood and therefore no swirls. That is what makes these so popular with many users.

In days gone past sanders used to be either a basic circular movement or an oval movement. With just a circular movement the finish would have had a lot of swirl marks on it.

The oval one was better but it was also much slower at doing the actual sanding. The random orbital combines both movements and that means a good sanding action plus a swirl free finish.

Main Types of Sanders

There are different types of sanders so before you buy one, just take a little time to read through this, and that will ensure you pick the right one. I have done a full article here on the different types of sanders available so as you can pick the right one for the jobs you are planning to do.

There are:

  • Belt Sanders – ideal for working on large surfaces and fast sanding
  • Orbital Sanders – these are older style sanders and good for sanding and finishing
  • Random Orbit Sanders – these have replaced the one above and are discussed in detail on this page
  • Straight Line Sanders – super for doing edges
  • Floor Sanders – for doing large floors quickly

Random Orbital vs A Belt Sander

Belt sanders are also a very useful method of sanding quickly. This type of sander would be used to sand a floor, a worktop or any larger and basically flat wooden surface. They are larger and will sand faster than an orbital version. Belt sanders do however tend to leave what are termed “directional markings.”

In addition these larger belt styles are not really practical to use on smaller wooden pieces, or on more intricate shapes like a chair.

The video below offers some really great advice on the best ones to buy and is well worth a look.

Who Makes Random Orbital Sanders?

The usual big brands will all make different models of these. For many users it comes down to simply picking their own favorite brand. Typical brands are:

  • Black & Decker
  • Bosch
  • Clarke
  • DeWalt
  • Dynabrade
  • Festool
  • Huscle
  • Makita
  • Milwaukee
  • Mirka
  • Porter Cable
  • Ridgid

Within each brand you will also find a number of different models. These range in price and also in the number of features available.

Top 10 List of Random Orbital Sanders

Product NameAverage RatingAverage PriceReviewPower
Dynabrade 59020 Dynorbital-Spirit Non-Vacuum4.9$160Find Out MorePneumatic
3M(TM) Random Orbital Sander 203244.9$170Find Out MorePneumatic
Dynabrade 69035 Dynorbital Silver Supreme4.9$180Find Out MorePneumatic
DEWALT D26451K4.7$63Find Out MoreElectric Corded
Makita BO5031K 5-Inch 4.7$85Find Out MoreElectric Corded
Bosch 1250DEVS 6-1/2-Amp 6-Inch4.7$245Find Out MoreElectric Corded
Bosch ROS20VSK 120-Volt Variable Speed4.7$80Find Out MoreElectric Corded
Black & Decker BDERO1004.5$30Find Out MoreElectric Corded
DEWALT D26453K4.5$80Find Out MoreElectric Corded
Bosch 3727DEVS4.5$150Find Out MoreElectric Corded
Festool 571817 ETS 125 EQ4.5$200Find Out MoreElectric Corded
Makita BO5030 5-Inch4.5$70Find Out MoreElectric Corded

Types of Random Orbital Sander

There are essentially two types:

  1. Random Orbital Sander
  2. Palm Orbital Sander (Smaller Hand Size Version)

Sizes Available

There are a number of different sizes available. The most popular by a long way is the 5″. You can also get 6″ versions. This measurement refers to the actual diameter of the disk on the bottom of the sander.

With some orbital sanders, you can actually swap the type of pad sizes, and make use of a range of disk sizes. This is usually done with an Allen key at the bottom of the base.

Most random orbital sanders will use what is called a hook and loop paper changing system. This means you do not have to use adhesive sprays which can get very messy.

Power Options

Mainly these are electric corded products. There are also cordless versions available and for heavier users a pneumatic option is probably the better choice, though will be more expensive.

In the buyer’s guide below, I have pointed out the main features that I think you should consider before making any purchase.

Random Orbital Sander Buying Guide

I thought I would put together a quick buying guide so as you know the important features to look for before buying one of these very useful tools. The power of the motor, the speed at which it can rotate and the more control you can have, then the better your product will be.

Prices

At the low end you can get one of these for about $30. At the higher end these will be around $200 and an average price of between $60-80.

For most people, and certainly for people wanting a good sander for projects around the home, spending around $60 will get you a very good quality product. If you are able to afford a little extra then you will get some nice extra features, though these are not always necessary.

One Handle or Two

You can buy these with either a single handle or with two handles. Just get the two handled version is my best advice as it simply gives you great control when you are doing your work. I have used both, and the double handle is absolutely the one to go with.

With most double handed models the second handle is simple to remove if you have to work up close to a wall or something like that. The smaller Palm sanders are all one handed but the larger ones can be either. Some people do prefer to operate these by one hand, and most of the products available can be used like this if you choose.

Motor Size and OPM

The size of the motor will ultimately determine the amount of power you have in your product. The more powerful the motor the better as it will last longer, and also apply more speed, as and when you need it.

OPM stands for “orbits per minute,” and is how quickly the sander can vibrate. The faster it vibrates the quicker you will sand, and the more wood you will be able to remove.

Typical values will be as follows:

Motors

3 -5 Amperes

OPM

7,000 – 12,000 OPM

Any sander that sits within the ranges show above is ideal for most projects.

Comfort

I list this feature as my number one feature to make sure you have. Typically if you are sanding down something like for example a chair, this can take a fair amount of time. Therefore you want the sander to feel good in your hand, not too heavy and not to vibrate very much.

That will mean you can avoid sore arms and that will allow you to work for longer. The better ones will come with rubberized grips for extra comfort. As I have mentioned some of these sanders come with two handles, which make it easy to grip the machine in different ways while you are sanding.

Dust Collection

When using any power tool, there will always be a certain amount of dust. However when using any type of sander there is going to be a huge amount of dust.

My strong advice is to make sure that whichever product you pick, there is a very good way of collecting the dust, or at least the majority of the dust. I would also highly recommend safety goggles and some type of dust mask.

These are not expensive purchases and will help stop getting grit and dust into your eyes and mouth (lungs).

Sanders can use either pleated filters, some type of attachment or a bag. The majority of these use what is called an on board dust collection mechanism. In my opinion having this method is a huge time saver.

The best sanders will have suction holes that are built right into its sanding pad. They instantly suck up the dust as soon as it is created when you are working.

The dust is sucked into a bag that is attached directly to the machine. Some models allow you to hook your orbital sander to the vacuum hose for great dust collection capacity. This is normally done through a small port at the rear of the sander.

Variable Speed

As the name suggests you will absolutely want to have speed control on your sander. It is this that gives you full control over the speed at which your sander will be doing its work. This is a very important thing to have so please do not buy one without this on it. (Most models will have this but be sure to check)

For example you may just want to try and remove an old teacup stain from a table, so will not want to sand too much. You will want to do this slowly. On the other hand if you were doing the edge of a table, you would want to quickly move along the edge and get the job done.

If you want to sand an acrylic or a plastic, then you will also need a slower speed, otherwise the material you are working on could get small burn marks.

Lock Control

If for example you are working on a bigger surface you will not want to have to continually hold the trigger in. Having a lock facility will keep the sander running until you want to turn it off. This for me is a vitally important feature to look for. It may sound trivial but if you have ever sanded down a table top, then you will know exactly what I mean.

Sealed Unit

Likewise, and because of the huge amount of dust that will be created, you do not want this to get into the workings of your machine. Make sure that you have what is called a sealed power switch. This helps a lot by keeping the dust out and as such will greatly enhance the length of time your new sander will last for. (Again most good models will have this as standard.)

Check The Base

Most random orbital sanders will have have a round base. Other finishing sanders and some orbit sanders may have either a round, rectangular or a square fixed base. They usually come as half sheet, third sheet, or quarter sheet sanders. This measurement is taken from a standard sheet of sandpaper.

Different Sanding Disk Grit Sizes

When using an orbital sander it is always best to start with rough sanding and working your way down to the finer finished sanding. This can be achieved by starting with a high grit of sanding paper, and then working your way down to a finer grit.

You can buy different sizes of sanding disks and these are available in different grit sizes, or more commonly in a combination of grit sizes. Most of these packs will contain round or circular disks which are easily attached to your random orbital sander.

Sandpaper

Sandpaper comes in many different grades. You need to know the right grade of the sandpaper that should be used with the particular orbital sander and the surface you are working on. The grade is measured simply by the amount of sand granules that are available per square inch of sandpaper.

When you see a lower grade this implies that it is course. At the other end of the scale one with a higher grade means it has finer sand granules. If you are doing a lot of work, then paper like this is not cheap, so just bear that in mind.

How They Work or Sand

The mechanism attached to the motor moves the base in what is called an eccentric motion. The amount of wood removed during the sanding process is mainly determined by the diameter of this eccentric motion.

Gears

They come as a direct drive or can be gear driven. In the direct drive method, the base is directly driven from the motor. With the gear driven orbital sander, the motor feeds into a gearbox. That gearbox then drives its sander base. The larger the orbital sander is then the faster and more wood can be removed. Typical sizes are 5″ and 6″.

Professionals will tend to go for gear driven, but most home users will simply not need this.

Maintenance

These are well made and pretty durable tools. The only thing that you really need to do is oil them on a regular basis. The typical lifespan, if getting regular use is about 4 years.

How To Use A Random Orbit Sander?

If you want to know how to use one of these properly and get the most effective use from your sander, then I have done a full and detailed article on how to do that. You can read that by clicking here.

If you have read this article from beginning to end, then hopefully you are in a better place to make a buying decision. My general advice would be that for almost all people then an electrical corded random orbital sander will be the best choice for most people.

Just make sure it is light in weight, has variable speed and is from a reputable brand who offer a good guarantee and warranty. It takes some time to master the art of sanding an finishing. When you achieve that though, then the sander that you hold in your hand can truly make a big difference.

My advice is not to pay any more than $70 for one of these as that type of money will get you a very good sander and one that will last for a long time. Don’t forget to change the sand pads on a regular basis as that will save you from damaging the surfaces.

If you plan on doing a lot of sanding, then for certain install some type of vacuum dust extraction as that will truly benefit you both in terms of your health, and in cleaning up afterwards. Many professionals have now turned to pneumatic tools and they do work better and are cheaper to use, once you have bought a compressor.

For most of us though an electrical random orbital sander at a price point of in and around $70-80 will be ideal.

Enda McLarnon
 

Enda McLarnon is now retired and is now enjoying writing about his love of power tools. All types of these tools are now available and they make working on projects and DIY jobs around the home a great deal of fun