Sanding ≠ sanding

What matters when it comes to sanding?

When sanding, choosing the right tool is crucial. Experts often talk about strokes, pad hardness and the right abrasive. They often fail to mention that one thing matters above all else: The right sanding motion. We reveal all.

Sanding motions and strokes

Depending on the quality of the surface and the result you want to achieve, there are five different sanding motions to choose from for coarse and fine sanding. It’s also true that the longer the sanding stroke, the more material is removed. A small sanding stroke of 3 mm, for example, is ideal for fine sanding; sanding strokes of five to seven millimetres remove a large amount of material for coarse sanding.

Linear

Sanding motion: Pure linear motion.

Application: Linear motion is ideal for sanding wood material along the grain.

Note: Sanding with a linear motion along the grain does not damage wood fibres (important if the surface is to be oiled, waxed or coated with a thin layer of varnish afterwards, for example). The linear sanding motion does not go out to the sides; linear sanders are therefore ideal for sanding frame sections adjacent to panes of glass.

Example machine: DUPLEX LS 130 linear sander

ECCENTRIC

Sanding motion: Oscillating motion, which combines overlapping linear and circular motions.

Application: Used when the quality of the sanding finish is not as important (e.g. if a top-coat layer is to be applied afterwards).

Note: The delta sander also has an oscillating motion; it is ideal for removing material on small surfaces with angles, corners and edges.

Example machine: DTS 400 delta sander

Eccentric rotation

Sanding motion: Combined oscillating and rotary motion.

Application: Suitable for coarse sanding (e.g. paint removal) as well as intermediate and fine sanding. Allows for a surface that is virtually free from any circular or ridged sanding marks

Note: When sanding using an eccentric rotary motion, it makes no difference whether the machine is moved with or against the grain; particular care must be taken when sanding areas where longitudinal and transverse wooden surfaces meet.

Example machine: ETS EC 150

Forced eccentric rotation

Sanding motion: Forced eccentric rotation as a result of connection to a gear unit.

Application: The gear unit considerably increases the material removal rate Suitable for coarse sanding and for quickly removing old paint layers that are not viable

Note: Quick removal of large amounts of weathered layers of paint and varnish, without a high risk of sanding errors. Forced eccentric rotation can also be used for polishing.

Example machine: ROTEX RO 90 and 150

Rotation

Sanding motion: Pure rotary motion

Application: Used wherever a high level of material removal is needed as quickly as possible (such as when stripping large areas of paint).

Note: Powerful rotary sanders are not forgiving of any user errors; unintentionally deep sanding marks can be produced when working on workpieces that need to be completely level.

Example machine: RAS 180