In the tool department of home improvement stores, you’ll find a vast array of sanders at a vast array of prices. While belt sanders are larger and more expensive, you can also find two products that look very similar, random orbit sanders and palm, or finish, sanders. Their prices are similar, but there are some big differences between the two. Before shelling out the bucks ($40-80), knowing the differences between the two will make you much happier with your purchase.
How they Work
Palm (or finish) sanders have been on the market for decades. They are designed to fit in the palm of your hand–hence the name. Sandpaper is attached to them usually with a clamping lever on either side of the unit. The exposed sanding surface is relatively square. Palm sander do not weigh much and can be used at odd angles. When the switch is turned on, the sanding pad vibrates and thousands of oscillations per minute. This action, combined with the weight of the unit provides the sanding mechanism.
Random orbit sanders are similar in size, though they often are a bit taller and weigh a few ounces to a pound or so more. The sanding pad on these is circular, and require special sized sandpaper discs to attach. The most common means to attach the sanding discs are with pressure-sensitive adhesive (PSA discs) or with hook-and-loop technology. Random orbit sanders work with not only the vibrations, but also with the random orbit, providing an extra amount of movement.
Palm Sanders: Pros and Cons
Palm sanders have several advantages over random orbit sanders. Cost is generally lower, with prices averaging around $40. They do not require special sandpaper, so you can buy large sheets and cut them to size. In fact, large sandpaper sheets are designed to be divided evenly for palm sanders and the less common third-sheet sanders. It is a simple matter to fold or cut a sheet of sandpaper into quarters and have a perfect fit with your palm sander. Most models include a small cloth or plastic “bag” to catch a majority of the sanding dust. These models require a certain pattern of holes to be punched into the sandpaper, to match the holes in the sanding bag where the dust is sucked through by the motor. Palm sanders include a template for punching these holes in their boxes.
Palm sanders do not remove as much material as random orbit sanders, and so are good for the final passes of finish sanding before painting or applying a clear coat wood finish. In fact, when sanding between coats of paint or finish, the palm sander is ideal, as there is less chance in sanding completely through the finish and having to re-apply the finish in those areas. Since the sanding surface is square, they are also able to reach into corners well.
Palm sanders’ weakness lie in the amount of material they remove. Even using a 60 or 80-grit sandpaper, palm sanders take a while to smooth out wood, and simply do not have the power to level an even area of wood. Likewise, paint removing is not within a palm sander’s capabilities. Many users also complain of hand and wrist pain, as the oscillation of the sanding pad is transferred through the entire sander. In some cases, palm sanders can cause hand numbness with extended use.
Random Orbit Sanders: Pros and Cons
Random Orbit sanders excel at material removal. Due to their increased rate and the orbiting movement of the pad, blasting through old paint and leveling uneven boards is simple and relatively quick. Belt sanders represent the ideal for serious stock or paint removal, but are also more dangerous and harder to use–they can remove material almost too fast, and ruin workpieces in seconds. Random orbit sanders strike a good balance here. They may also be used for finish sanding, but because of their more aggressive power, should not be used for sanding between coats of paint or finish.
Random orbit sanders require a special sandpaper, since most sheets of sandpaper do not come with PSA or hook-and-loop backings (and cutting a circle is very hard!). But applying this sandpaper and removing used sheets is a quicker operation, especially with the sanders that use hook-and-loop pads. Sandpaper also comes pre-punched to match the existing dust collection holes in the sanding pads, so punching the correct number of holes is unnecessary.
Dust collection on many random orbit sandpapers is superior to palm sanders because of the stronger motors included in their housings. Despite this, they do not seem to vibrate and cause hand numbness as palm sanders do, though fatigue can set in after some time, as with any repetitive work.
The biggest disadvantages to random orbit sanders is the their cost, averaging $15-20 more than many palm sanders. Also, the cost of sandpaper for these units is also more than palm sanders, and the selection of various grits is more limited. One can easily find grits ranging from 60-600 in standard sheet sizes, while the circular sheets required for random orbit sanders may only range from 100-320 grit. However, because they are more aggressive, heavier grits are not quite as necessary for stock removal, nor are ultra-fine grits above 320 appropriate.
Finally, the circular pads on random orbit sanders prevent the sanders from operating in tight spaces and corners of objects, and the are slightly more prone to tipping on the corners or edges of a workpiece. This results in rounding over the edges of workpiece unintentionally, and ruining its appearance.
Which One To Buy
Dedicated shop enthusiasts and wood workers would probably benefit from having both a palm and a random orbit sander in order to play to each of the sander’s strengths and avoid their weaknesses. However, for those just beginning would most benefit from spending the few extra dollars and purchasing a random orbit sander, due to their versatility. After all, finish sanding by hand with 320 grit sandpaper is not nearly as taxing as attempting to level ridges and remove rough areas from raw lumber. Also, for those who refinish furniture, the random orbit sander excels at paint removal. Just remember that finish sanding should be done by hand.
Palm sanders alone may be best suited for the average homeowner or handyman whose sanding needs are more infrequent and only has the occasional piece to repair.