Electric Sander & Air Powered Sanders
Looking for a new sander for your woodworking projects? We look at the orbital, random orbital and dual-action sanders in detail.
If you are doing a number of sanding duties, you should possibly investigate adding a power sander to your shop. They can take some of the mononity out of the sanding procedure and in the hands of a skilled guitar finisher they can save a tremendous amount of time.
When used improperly however, they can ruin a finish or a carefully assembled guitar body or neck. The most commonly used sort of power sanders are the random-orbit and orbital sanders. The DA sanders, which are air-powered, an much less common as they require a very large compressor to operate properly.
By using an electric sander or air-powered sander, you can greatly speed up sanding operations on the larger flat surfaces, but be very careful not to remove too much material. You would be best to leave sanding on edges, contours and other detail work to other specialized sanders or sanding by hand.
Random-Orbit electric sanders leave much less sanding marks or scratches because of the way they operate by making the sanding operation in random circles rather than just small circles.
Orbital electric sanders leave the most sanding scratches of any of the three power sanders outlined here. The sanding marks left by the random-orbit sanders are barely perceivable to the naked eye, and you can use coarser grit without the worry of leaving deep scratches in the finish, as the secondary action of the sander removes the scratches.
Dual Action (DA) air-powered sanders leave even fewer marks and are more powerful, but these are air-powered and they take a lot of air pressure to run.
Orbital sander were among the first generation of vibrator type sanders and this was the first type of sander that I purchased for my guitar-making business.
The vibration action is a result of an offset weight being placed on the motor shaft causing the sanding pad to move in a circular motion.
These varieties of sanders have either a rectangular or square sanding surface pad that does not rotate. Normally the sandpaper is clipped to the bottom of the pads on these sanders.
I remember the best one that I had was an old Porter-Cable Block sander that just about shook me to pieces by the time I was done sanding - but I have to admit, it did work quite well - at least it was a whole lot faster than sanding by hand.
For musical instrument work, random-orbit sanders are an incredible leap above the plain orbital sander. Although they can still be new to many woodworkers, random-orbit sanders are electric woodworking counterpart to the dual-action (DA) air-powered sanders used for decades by automotive finishers.
Like orbital sanders, random-orbit sanders also sand in a small orbital pattern; in addition to the circular or orbital motion the pad additionally rotates slowly, which acts to remove any trace of circular sanding scratches.
I purchased a few of these several years ago and I couldn't believe the improvement that was made in sanding technology over and above the old orbital sanders. Currently I have a Porter-Cable, a Milwaukee and a Dewalt - all shown here and they are very comparable.
If I were choosing today I would look for the following features:
Variable Speed: This will give you a lot of flexibility for many different sanding operations:
Dust Pickup: I'm allergic to much of the dust of the exotic woods now and this is a must for me - it should be for you too.
There is a braking mechanism that prevent keeps the pad rotating at a consistent rotation and in an integral part of the action.
You will find the most common types of sanding discs by either hook-and-loop, which is basically a velcro system, or by pressure sensitive adhesives. I would definitely suggest an electric random-orbit sander for the small shop.
Like random-orbit sanders, DA sanders can be held approximately flat to the work and therefore do a good job of sanding flat surfaces.
One notable feature of the air-powered Dual Action sanders is they can operate at random speed, Which gives you a number of control in the amount of material that can be removed.
At the higher speeds they're much more aggressive than random-orbit sanders, so if you need to remove some wood-such a rough-carved top for instance - a DA sander will have its place in your shop. It seems as though these sanders with the model that was used in the development of the newer random-orbit electric sander models.
One thing that you need to know about the air-powered models is they necessitate a tremendous amount of air to operate properly. An air compressor with a minimum of 3 horsepower or better would be needed. For a small shop this kind of equipment will be very expensive and the noise that is generated by these large compressors is very damaging to your hearing. Therefore some distance and segregation is compulsory for these big compressors.