In Brief.

An electric orbital sander works by vibrating the sanding pad in small circles referred to as ‘orbits’.  The distance of these orbits typically ranges between 1.5mm-2.5mm, although larger orbits are not uncommon. This orbital action, combined with the operator’s pressure & sanding action, results in a sanded finish in preparation for lacquering or painting. Generally, the larger the orbiting width, the more aggressive the sanding action.

An orbital sander is generally used to obtain a fine finish & is not really suitable for serious moulding or the removal of large amounts of material.  Orbital sanders are commonly used following the work of a belt sander, or other similar more aggressive sanding machines. In more recent years random orbital sanders have become a popular & sometimes more expensive choice as a finishing sander. Random orbital sanders work in a different way than traditional orbital sanders & have higher rates of material removal. A random orbital sander can, using a fine sanding disc, leave a relatively fine finish. Traditional orbital sanders are still the least expensive option & tend to perform a better job when sanding flat surfaces.

Sandpaper is generally manufactured in a large standard sized sheet & cut to fit each particular size of sander. In some cases you will notice that the traditional orbital sander is referred to according to the actual proportion of sandpaper that it uses from the original standard sheet. (eg. ? sheet orbital sander).

What We Did.

We operated the sanders over an old timber storage shelf that required some light sanding in order to remove years of built-up dust & grime. The actual shelf was made of medium density fibreboard, which is commonly referred to as MDF.

We used a variety of sanding sheet grit with each sander in order to perform our tests.

What We Found.

We reviewed a wide variety of orbital sanders differing in price, physical size, pad size & motor size. Prices ranged from a low $40 right up to $700! The smallest sander tested was a small ‘iron shaped’ sander right up to the larger ½ sheet variety. Motor sizes ranged from 150w-400w.

Only one orbital sander, the Festool RS200EQ Plus, came with variable speed control.

On completing our tests, all machines seemed capable of doing the job they were designed for, especially in regard to size, price & expectations. All provided a fine surface finish.

The smaller sanders have an obvious advantage in that they are easier to manoeuvre within confined areas.  The larger machines are more efficient in use, as they cover a large area with each pass.  A larger sanding pad is more ideal for removing high spots. Conversely, a smaller sander may be better suited when sanding ‘dips’ in a surface & is generally better when following surface contours.