A standard 3/8" pneumatic drill with a foam sanding
mandrel makes a great tool for power sanding
Random Orbit Sanders - Overview: Most woodturners would agree that sanding is one of the least desirable parts of the woodturning experience. Thankfully, new tools like improved pneumatic sanders, as well as high-tech abrasives have become available in the last few years that make sanding not only easier, but faster as well. Almost any electric or pneumatic drill can be outfitted with a foam-backed sanding mandrel and a hook and loop abrasive disk for a cost effective and simple sanding solution.
For years, this is how I sanded my faceplate projects and hollow forms. In the early days of my studio, I used electric drills with foam sanding mandrels and either sticky backed, or hook and loop backed abrasives. This approach worked well enough initially, but as the volume of my business grew, I quickly found out that few electric drills were up to the task of prolonged use.
Using a Sioux Dual Action sander to finish
sand a natural edge Honey Mesquite platter
After I burned up five new electric drills over the course of one summer, I switched to pneumatic drills for all of my sanding. While the move to pneumatics eliminated my failure problems with electric drills, I was still limited to rotary action when sanding. While rotary sanding is a great choice for many sanding tasks, it is far from ideal for others.
Quest for a New Finish Sanding Solution
Like so many things in life, there is no single tool, protocol, or product that is best at everything. As my studio continued its growth, I began to experiment with other tools to sand my projects including passive (inertia) sanders, ultra high-speed sanders (15,000 RPM Right Angle Grinders), giant electric rotary sanders with 5" and 6" disk heads, random orbit sanders (also known as "DA" sanders) and numerous versions of similar tools that were pneumatically powered.
Dynabrade's pneumatic palm sander features a
3" Velcro-faced sanding pad and a 3/16" orbit
When the dust had settled, I found out that Random Orbit Sanders (ROS) offered the extra performance I was looking for when my rotary tools fell short. Very few woodturners I've met through the years use random orbit sanders in their studios. When asked why, most say they're too expensive, they don't work well and can be cumbersome to use on smaller projects. While I would agree that ROS can be a wee bit expensive, they can be very useful in certain sanding situations.
Most of the bad rap that random orbit sanders get comes from the fact that they will stop if you press to hard on the pad whilst sanding. Random orbit sanders do not turn the abrasive pad only in a circle like a standard rotary drill; rather they spin the pad as the pad moves in an eccentric orbit. This simultaneous spinning and oscillation creates a very effective sanding action. However, if you are a bit heavy handed the pad will simply stop, whereas a rotary sanding tool like an electric drill will slow a bit, but keep on running.
However, when you're working with the finer abrasive grits (P400, P600, P800 etc.), the dual action of a ROS produces a more uniformly sanded surface than a typical rotary tool. This is especially true when sanding inlaid crushed stone, sanding across metal band inlays, sanding timbers that feature significant differences in the density between early wood and late wood, or when sanding spalted timbers with a highly variable structural density to name a few.
The key to using random orbit sanders is to think of them as a final finishing tool, not a primary sanding solution. If you keep a light touch and limit the ROS to the final finishing grits only, a ROS can produce superb results.
Random Orbit Sanders for Woodturners
AirVantage's 5" random orbit palm sander is an
excellent choice for medium to large size projects
One of the criticisms I've heard about ROS is that they are just too large for the average turned bowl or platter. In the past, many ROS featured pads that were 5" or 6" in diameter, which severely limited their use in the average woodturner's studio. However, in recent years small palm sized ROS sanders have become available that feature 2" and 3" Velcro faced sanding pads. There are even a few models with 1.5" pads, so pad size is no longer an issue.
Another complaint I've heard is that the size of the random orbit sanders is too large for smaller projects typically turned on lathes. While it is true that older ROS had orbits that were better suited to flatwork projects, newer ROS have orbits as small as 3/32," which is about half the orbit size of a typical ROS. This means the size of the orbit is also no longer an issue.
Grex's Dual Action sander features a very
powerful motor with a 2" Velcro-faced sanding pad
The last complaint I've heard is that ROS are too expensive. Some models do indeed have prices that hover in the stratosphere, but there are some affordable models as well. Newer palm sized models are easy to use and comfortable in your hand. The smaller 2" and 3" pads offer a seamless transition from rotary tools and are the perfect size for most faceplate projects. The tiny 1.5" models offer even greater range capabilities, as do the 5" and larger models.
Random Orbit Sanders: Advantages
Sioux's Dual Action sander features
a 3" Velcro-faced sanding pad
Random Orbit Sanders: Disadvantages
Using a Dual Action sander to finish sand
the outside of a 16" Honey Mesquite
bowl with 800-grit abrasive
As good as ROS are for finish sanding, I do not feel they offer significant advantages when using course abrasives. Therefore, I limit my use of ROS to grits above 400 grit (P400) and use traditional rotary pneumatic or electric tools for courser abrasive work. My typical protocol for a bowl is as follows:
Using the 3" AirVantage pneumatic palm
sander to finish sand a Mesquite platter
with 800-grit abrasive
If you already have a suitable compressor, take a look at a palm sized ROS. Try it on some of your projects and see what you think… If you're like me, you'll find that a ROS is another tool worthy of being in your woodturning toolbox. It gives you additional options for those projects that can benefit from the dual sanding action and on those that incorporate mixed media inlays.
Metabo's electric random orbit sander
features integrated dust control and a 3"
Velcro-faced sanding pad
If you do not already own a compressor, look for electric model ROS or stay with your current rotary action sanding options. The costs involved with getting setup for pneumatics can be prohibitive and may be better spent on other tools that will help you to grow as your needs and desires change.
Safety Note: Always follow all manufacturers safety instructions before working with your lathe, or any of the tools or products you may use. If you are unsure about any operation, obtain competent professional instruction before proceeding. Use and wear all necessary safety devices during turning and observe safe woodturning practices to prevent accident or injury.
Steven D. Russell is a professional studio woodturner, teacher and writer. He has written numerous articles for international woodturning magazines, which have been published in more than 78 countries around the world. Steve has demonstrated in numerous cities across the United States. His studio, Eurowood Werks, specializes in bowls, platters and hollow forms with unique visual and tactile treatments.
Steve is also the current and founding President of the Lone Star Woodturners Association, Inc., an AAW member chapter. The LSWA is a 501(c)3 non-profit educational organization dedicated to teaching and demonstrating the art and craft of woodturning.
Steve is also a featured writer for the Guild of Master Craftsman's "Woodturning" magazine, published in London England. Woodturning magazine is the world's leading magazine for woodturners. Look for his articles covering technical topics, or project based articles in an upcoming issue.