What’s the difference between an Orbital Air Sander and a Random Orbital Sander?

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At first glance, an random and a  orbital air sander and a seem like the same type of air tool. While this is a common mistake, these sanders are designed for different applications and their proper use can either make or break your project. This article briefly describes the difference between these two sanders.

            An orbital spins in an eccentric circular pattern that creates a small circular pattern. This pattern produces a scrubbing action that sands the work area in all directions. The sanding action is not as rough as a random orbital sander. It  is best used for light sanding or finishing work. You would typically use an orbital after you have used either a belt sander or a random orbital sander to rough sand an area. Think of them as a light duty sander. One of the most popular versions is a palm grip orbital sander. These smaller varieties are excellent for getting into tight areas and finish sanding on furniture. The larger versions are used for sanding larger surfaces: wood paneling, large tabletops, kitchen cabinets, and doors. Large or small, the orbital is best used for the final sanding or for more delicate surfaces.

            Random orbital sanders are more powerful and used for more heavy duty applications. They employ a different spinning motion than their orbital brothers. A random orbital spins the sandpaper disk as it rotates the pad around in a wobbly motion. This action removes wood and material faster than an orbital sander and more aggressively. Most  are used in auto body shops for smoothing fenders and sanding down primer before the paint is applied. If you have a shop air compressor, we would recommend the air powered versions. They are lighter and generally smaller in size than their electric cousins.

    The basic difference is power and abrasiveness. Orbitals are more for lighter sanding and randoms are for more aggressive work.  You need to understand the difference to keep from possibly ruining a nice piece of furniture or messing up a counter top surface. There are different models and sizes to choose from. Each has specific jobs and t asks in mind. If you are not sure, just test it out on an old piece of wood or metal. This will ease you mind before you tear into  the main task at hand.

    Pads on all models come in ready to accept one of two kinds of sanding disks: stick on paper coated with a pressure sensitive adhesive or press on disks with Velcro fasteners. Both styles also come in square sheets that fit the pads on many sanders. If you are not sure, buy a PSA model because you can always retrofit the pad with Velcro later if you need to. The advantage to using Velcro type sander is they can easily be reused and much more convenient for projects that require different types of sand paper and frequent changes. However, adhesive types are less expensive and better for jobs that require a lot of sanding with the same type of paper. The big disadvantage is they are difficult to reuse.