Tools 101: how to use power sanders

There are two main types of sanders:

• belt sander
• orbital sander

Belt sanders

A belt sander is used for sanding very rough surfaces or surfaces that need levelling or shaping. They are best for DIY projects like taking the top layer off hardwood floors, especially when the joins in the wood are uneven. They can only be used for flat surfaces. 

Orbital sanders

Orbital sanders come in a variety of shapes and sizes, so can be used for a variety of sanding projects. The base is available in a range of shapes and sizes, but the pad will perform a circular action, smoothing the surface without leaving marks. A circular base is more effective for larger areas, while a pointed tip (often called a detail sander) is best for tight corners and harder-to-reach places. Orbital sanders are great for preparing surfaces for painting, shaping wood, or sanding around curves – for example, if you need to sand down a wooden doorknob.

Most sanders will come with a dust bag attachment, which are designed to extract the debris through the exhaust vents. This results in a cleaner work area and reduces the frequency in which the dust clogs the paper on the machine.

Choosing the right sanding grit

Before you start sanding, you’ll need to select the right sanding pad or belt for your project. Usually, you’d start with a coarser grit (40, 60, 80) – this will help remove the majority of scruffs and finishes. You can work up to a belt with a finer grit (180) for the final touches.

Changing the sanding belt or pad

For orbital or detail sanders, the pads have a hook and loop back (similar to Velcro) – simply line up with the base and stick on. When you are ready to change grit, you simply peel it off and attach the next one.

When using any type of power sander, it’s safest to put on safety goggles, ear protection and wear a dust mask. These precautions will protect you from the wood dust that accumulates in the air as you sand.

The first thing to do with a belt sander is locate the tracking knob by turning over the sander so the front handle is resting on the table. Then, you’ll need to check the belt to determine which direction it needs to be tracked. To do this, revert the sander to its original position, turn it on and look to see what direction the belt needs to be tracked. If it needs to be changed, turn the knob clockwise to move the belt to the left, or counter clockwise to move towards the right.

After this, it's as simple as moving your sander with the grain of wood. Before applying it to the surface, turn it on and let it run for a few seconds to get it up to speed. Gently ease onto the surface, making long, even strokes along the grain.

Apply a steady pressure to ensure an even finish, but avoid pressing down too firmly as this can gouge the board. Stop and check your work as you go – the last thing you need is an uneven sanding job! 

For the orbital or detail sander, the first thing to do is switch it on and let it rise to full speed. Then gently set it on the surface, applying gentle pressure as you move in the direction of the grain.

These types of sanders are designed to finish surfaces rather than create a shape so it’s important not to push too hard. Keep the base flush to the wood to avoid creating undulations in the surface.