All About Disc & Belt Sanders

Using a static sander needs grit and determination – we have both!

Hands shaping wood on a sanding machine

Once you have sawn and planed your wood there comes joint cutting and shaping which is much more easily done if you have a static disc or belt sander. A disc sander can effectively cut as well as sand to shape because relatively small areas are presented to the disc and with a coarse 80 grit disc in good condition, creating curves, bevels etc is stunningly quick. A belt sander is slower because it is used more for long grain edges but it can ‘true up’ and flatten a surface before using an orbital sander and the ‘nose’ at the front is excellent for concave shapes.

Static Disc Sanders

You can extend the life of a sanding disc by bandsawing most waste away before presenting the workpiece to the disc so only a smaller amount needs to be sanded. You can buy a special soft rubber compound block for unclogging the disc surface or use a piece of garden hose and apply it to the running disc. If the disc remains clogged it gives slow and uneven sanding and the workpiece surfaces become burnt, so it is important to regularly clean up the disc.

Disc sanders nowadays come with the ‘upward’ side of the disc (usually on the right hand side) fitted with a metal cover. This is because the workpiece can get ‘thrown’ upwards if you are using the entire width of the disc. Older machines don’t have a cover which allows more complex shapes to sit closer to the disc during sanding. Fixed static belt sanders are usually part of a machine with a disc sander as well, it may be smaller than a disc machine on its own so you need to decide if you want to have both in one machine.


A small combined belt and disc sander complete with fences and mitre protractor
Circular saw with disc sander attachment.
You can cut and fit two different grit grades together so you can use which ever is most suitable
Sanding wood with a disc sander machine.
Older machines carry a risk of the workpiece kicking upwards if you use the entire width
Wooden board being cut by circular saw.
This disc has become clogged and will give a very scorched uneven finish
Sanding wood on electric disc sander in workshop.
Sanding curves is typical disc sander work, you can create very even radii
Using a disc sander on a wooden block
Modern disc sanders have the ‘upwards’ side covered for safer usage

Static Belt Sanders

A belt sander offers different sanding options and will normally have a fence alongside and one across the sanding bed. These will keep the workpiece perpendicular to the belt and safer to use as well.

Belts and discs are ‘open coat’ which means they clog less than hand-applied abrasives. A coarser grit works best since the machine runs fast tending to cancel out a certain level of scratch marks. 80 grit is probably favourite unless you are sanding small objects in which case 120 grit is a better option. Belt are easily replaced as they are held in place by a spring tension mechanism which is easy to release.

Discs are more difficult to change because the sanding table in front restricts access, often it is easier to swing the table downwards so the gap in front of the disc increases. The two disc mounting options are self adhesive which lie very flat but are hard to remove cleanly, a woodturner’s scraper is a useful way to quickly scrape the aluminium backing disc clean. The other type – hook and loop – are thicker and pressure can dent them slightly. They are also difficult to attach and release as they grip suddenly in the wrong position. A thin piece of worktop laminate works well as a ‘release’ divider pushed down between the hook and loop material.

Wood sanding with disc sander
If you don’t have a mitre fence with your sander you can make up your own
A belt sander has a rounded front end perfect for sanding internal curves
Green tube friction testing on belt sandpaper
A piece of garden hosepipe being used to drag wood dust off a moving belt

Personal Safety

Sanders can be quite aggressive when you least expect it, small objects should be held firmly in a device or jig so your fingers are nowhere near the abrasive. Extraction is a must as sanding of any kind produces the fi nest, most dangerous dust particles. Ensure the extraction is working well and if necessary make up a hood to partially enclose the sander to help the extraction work. You must wear a good quality FFP2 category dust mask or a powered respirator.

Further Reading

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