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Difference Between Random Orbit & Finishing Sanders

Random Orbital Sanders

You might enjoy building a treehouse with your daughter or setting up a small meditation shed in your backyard, but the part where you need to sand the wood planks is always the worst. It’s messy, it makes you choke on the flying dust and the feeling is the same as nails on a chalkboard. But if you’re a true DIY-er, sanding is one of those steps that you just can’t leave out.

Electric sanders make the job relatively faster, easier and a bit more bearable. However, there are different types of sanders and today we’re going to look at orbit and finish sanders, what each of them does and which one is better for your task on hand.

What Is a Random Orbit Sander?

Before we get started, let us just point out that orbit (or orbital) sanders are NOT the same as random orbit sanders. While the two share some common features, the main difference is the shape of the sanding pad: orbit sanders have a square sanding pad whereas random orbit sanders have a round one.

The pad at the bottom of the random orbit sander moves back and forth as the base plate rotates in a circular motion. This circular motion helps alleviate the marks left behind by sanders with a square base. They have a long gripping handle giving you a greater amount of control as you work.

Random orbit sanders tend to be quite powerful, so you need to be very careful when using it to avoid applying too much pressure on one spot and accidentally creating a depression in the wood. In fact, for sandpaper of the same grit on the finish and orbit sanders, the orbit sander will help you get the job done much faster.

Random orbit sanders can be tricky to use when sanding the edges of your surface. The circular pad doesn’t fit into the edge (especially if it’s a straight, 90-degree angle) and can potentially dent the side experiencing more pressure.

They require special sandpaper that fits the particular model that you are using. The base of the model may have a different diameter and different number and size of holes and your sandpaper pieces need to fit accordingly. The more recent designs feature a Velcro stick as opposed to the traditional tac stick. The plus side is that removing and reattaching the sandpaper is a breeze.

Once you get the hang of it, random orbit sanders can make your job much easier since you can vary the speed at which it runs, and control the motion so that you’re not left with marks on the finished surface.

They tend to be a bit more expensive than finishing sanders, but you can choose from a variety of models and they’re better if you’re doing professional work.

What Is a Finish Sander?

The finish sander is characterized by a square (or in some cases, rectangular) base as opposed to a round one on the random orbit sander. They’re considered to be the more traditional sanders, but many crafters still opt for these since they’re relatively light on the pocket. This one only moves back and forth and tends to leave swoosh marks behind on the surface you’re sanding. The grip is the top of the sander which can be a tad bit uncomfortable but isn’t really a deal-breaker.

Finishing sanders are also great for beginners since they’re not so aggressive and leaving the sander in one place for too long won’t damage the surface. They also offer the benefit of being the better option for sanding edges. The squared edge of the sander fits into the edge between, say, two pieces of wood without denting either of the pieces.

Finish sanders don’t really require special sanding paper. While you can find pre-cut squares to fit on the base plate, you can even get regular sheets of sanding paper and cut them to size. The older models of finishing sanders feature a lever system to fit the sandpaper into place that can be quite tedious. The newer models have a clasp system that secures the sandpaper into place as you work. Opening the clasp helps you easily remove the sandpaper once you’re done.

If you’re doing a quick task which doesn’t really require a neat, professional finish, a finish sander can easily help you get the job done.

The Basic Differences Between Orbit & Finish Sanders

Orbit Sanders

  • Smoother
  • Faster
  • More powerful
  • Offer variable speed
  • The round plate doesn’t leave patches on the surface
  • Special sandpaper required
  • Sandpaper easy to fix and remove
  • Suitable for open surfaces (not great for edges)

Finish Sanders

  • Slower
  • Less power
  • Square/rectangular plate leaves patches on the surface
  • Can be used with any type of sandpaper
  • Attaching and removing sandpaper is annoying
  • Ideal for sanding edges and crevices

When to Use Which Sander

Although orbit sander usually comes out on top, if you’re working on a dresser or bookshelf with straight edges, you will also need a finishing sander for the edges and corners. The random-moving base of the orbit sander will be unable to get into the crevices without leaving some telltale signs behind. In the worst-case, it may even damage the surface.

So Which One is the Better Option?

If you have the room in your budget, it is recommended to have both a finish sander and a random orbit sander in your toolbox. If you’re working on a large project and you need to sand the edges, the finish sander can do the job. For the rest, you can use your orbital sander to get a smooth, clean finish.

If you’re a novice, you can test the range of motion and the speed with which your sander sands a scrap piece of wood. Take your time, and only start on the real project once you’re sure you can do it right. Orbit sanders can ruin your work surface if you haven’t figured out how to use them properly, so make sure you read the instruction manual (and consult a professional if necessary) before getting started.

If you need to choose between one, the orbit sander is definitely the better option since it’s faster to work with and the finish is very smooth.

Whichever sander you work with, it’s important to follow the necessary safety precautions. While electric sanders have their own dust bags, it is advisable to wear a dust mask to ensure that you’re not inhaling any stray dust particles.

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