A finishing sander is typically used to prepare the surface for finishing. Both random orbit sanders and orbital sanders can be used as finishing sanders. Here we are going to focus on the orbital sander, sometimes also called finish sander. Click here if you want information about random orbit sanders.
Orbital sanders are not as popular as the more versatile random orbital sander but they are still useful for a number of sanding tasks. Orbital sanders are divided into two main types, the two-handed model and the palm model. Typically, the two-handed orbital sander is powerful and can be used both for aggressive sanding as well for creating a smooth surface. The palm orbital sander is compact and very good for sanding in confined spaces.
Compared with the random orbital sander, the orbit sander has one drawback, it has a tendency to leave swirl marks. Fortunately, swirl marks are easy to remove manually, using a sanding block. By working as much as possible with the grain, you minimize the risk of swirl masks.
The palm finishing sanders generally use square sheets of sandpaper, typically ¼ sheets. The small size and light weight makes them easy to operate. Newer models generate very little vibrations and are relatively quiet. The two-handed orbital sander typically uses ½ sheets. Note that sanders that use sheets of standard sandpapers are sometimes called sheet sanders. Thus, a finishing sander has a lot of other names.
Typically, the sandpaper is secured with clamps. You can change sandpapers easily and reuse the sandpapers until they are completely worn out. The hook-and-loop system used by many random orbital sanders may be easier to use but you don’t need to worry about replacing the sanding pad. Buying sheets of sandpaper is also cheaper than Velcro disks.
The competition from cheap random orbit sanders is tough but a small palm finishing sander is still unbeatable for sanding in confined spaces. Since sheets of sandpaper are cheaper than the round disks used by random orbital sanders, the running costs will also be lower.
Sanding requires good dust collection and most modern finishing sanders come with reasonable dust collection. But using a shop vacuum is a much better solution. Note that if you want to use your shop vacuum, you need to make sure the finishing sander has a dust collection port which fits your shop vac. An adapter may be required.
Although finishing sanders are not removing stock as aggressively as most other sanders, it is still recommended to wear goggles and a dust mask. Finishing sanders are relatively quiet but sanding is a noisy task so ear protection is recommended.