7 Common Problems With Random Orbit Sanders – How to Fix

A random orbital sander (ROS) is one of the handiest electrical sanders and a useful tool you can use as a woodworker or DIYer. But first, you must know how to sand wood with an electric sander.

The ROS spins in circles and orbits in a small elliptical motion. This process reduces swirl marks and produces random scratch patterns. They are marvelous in the power tool technology, but they can also be frustrating at times. So here are the solutions to the seven common problems you may encounter with your random orbital sander.

Seven Major Problems and Their Solutions

Here we’re going to find out the solutions for the seven common drawbacks of the ROS.

Problem #1

Problems Regarding Swirls or Pigtails:

Though random orbital sander (ROS) reduces big circular marks left by the spinning discs of old rotary sanders, it can still leave tiny little swirls behind. They are sometimes called pigtails or spirals. These marks stand out, especially when you put on a finish or stain.

There are several potential reasons for these swirls to happen and have particular solutions to those problems.

Fragile Sandpaper

A tad bit of abrasive grit from your sandpaper came off and got stuck in a different spot. And now it’s digging profoundly in that spot, making spiral patterns.

Solution: You may get some better sandpaper that doesn’t break up as you use it. 

Dusting Problem

It could be the dust that built up and compacted into a tiny little ball, creating some type of lump, and that can also dig deeper as you sand, creating swirls.

Solution: The solution is to keep your sander clean. You can either use a sander with a well built-in dust collector or attach a shop vacuum for the dusting problem. 

Quick Movement

Another cause for the spirals is moving the sander back and forth too quickly many times over the same place.

Solution: Sand slowly. Take about 15 to 20 secs to travel afoot and then move on to the next area. Also, Remember that the disc is orbiting in circles. It’s going to leave circular scratches. The key is to leave thousands of them so that they’re closely blended together. If you move the sander side to side too quickly, you stretch those spirals out, and you make it more noticeable. Read more: 8 Best Oscillating Spindle Sanders Analysis

Problem #2

Dust Clogging

This problem is related to the last one, but it’s way more profound. When you sand using a coarse grit, the dust can build up quickly. Some ROS have reasonably effective built-in dust collectors; some don’t. If you let your sandpaper to clogged up, it’ll stop working well. You’ll have to sand a lot longer than usual. And the clogged piece of paper will also build up heat and dull more quickly.

Solution: Sanding with coarse grits can create a lot of dust. A quick fix to dust clog is to use a shop vacuum. Also, if it looks clogged, rub it with a rubber stick to clean it up.

Problem #3

Loose Discs or Slipping Discs

The orbital sander models on the market use a velcro system that allows them to change out sanding disks conveniently. While convenient, this system has drawbacks like- disk slipping. When the sander doesn’t grip them well, they can fly off and cause hazards. Also, a loose disc diminishes the performance of the tool.

Solution: Though it is pretty frustrating, the answer is here! First, check if it is a dust buildup. If yes, clean the velcro pad. Second, switch to the appropriate sandpaper brand for your model of the sander. Third, change the velcro pad if you wore it out either by applying excessive pressure or melting the little plastic hooks on the bottom by building up a lot of heat while sanding.

Tips: You could buy a replacement pad for your sander or get some adhesive-backed velcro strips and glue them on the bottom. Better yet, you could buy a carbide sanding disc that lasts way longer than regular sanding discs, which will come with a new velcro piece. And to avoid slipping, always store your orbital sander leaving a sanding disc on the base. This prevents the velcro hooks from bending and flattening and losing their grip over time.

Problem #4

Paper Loading

Paper loading occurs when the grit on a piece of sandpaper becomes loaded with sawdust. It happens in the case of ROS more often than other sanders as it has a comparatively smaller sanding disc at around 5-inch in diameter. So, the disc becomes useless and needs replacement frequently, which is quite annoying. 

Solution: Check the sandpaper periodically as you work. Replace the sanding disk as soon as you suspect the paper is loaded with dust.

Problem #5

Spinning Without Random Orbit

One of the common issues for an orbital sander is that it leaves circular sanding patterns on the workpiece. It occurs because the disc is spinning, but the device is not randomly orbiting.

Solution: You can solve this problem by greasing the engine bearings rigorously. While the work is quite extensive, I would recommend following the manufacturer’s guide for further instructions.

Problem #6

Uneven Sanding and Burn Marks

Another common problem with the ROS is uneven sanding, whether caused by tilting the machine or pressing down the sander on a high spot and burn marks. Because pressing down the sander reduces the tool’s efficiency and slows down the motor’s speed.

Solution: To solve it, draw a wavey line across the surface. Keep your sanding disc flat while sanding.  Make sure to remove the pencil marking evenly. Keep it in work with overlapping passes following the grain of the wood. Don’t pressurize the sander. Instead, let the weight of your hand and the tool do the job.

Problem #7

The sandpaper dilemma

The final yet common issue is to choose the right grit for your sandpaper. Because if you skip from 100 to 220, you’re going to sand the scratches from the hundred forever. And you’re likely to leave some of those spirals behind.

Solution: Though the sanding grit goes from 80 up to 320 (80-100-120-150-180-220-320), you don't need to buy all of them. Don’t skimp on your grits, either. Buy your sanding disks in 100, 150, 220, and in finer grits considering the precision you want in your work. It’s faster and more efficient when you use several increments instead of just two or three.

Lastly, hand sand your project after machine sanding for more precise texture.


We all get impatient when we’re sanding. The key is to keep patient and do your job until you’re satisfied. It is also mandatory to choose an accurate random orbital sander for your woodwork for more outstanding performance. Do call in any expert advice if necessary. More importantly, follow the manufacturer’s guidelines as you work.

I hope these tips help you get more from your ROS. Revisit us for any further queries.

Last Updated on February 5, 2021 by John Dylan

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