Build a Double-Sided Sanding Block from a Sanding Belt
A good sanding block makes smoothing large, flat surfaces easier and helps keep the surface level. But constantly replacing worn sandpaper can interrupt the job.
To make hand sanding more convenient, I built this double-sided sanding block that uses an ordinary sanding belt instead of individual sheets of sandpaper.
The belt slips over a wooden block, and a simple tension bar holds it securely in place. Since the abrasive wraps around both faces, you get two usable sanding surfaces in one handy tool.
It's an easy woodworking project that makes good use of a sanding belt while providing a comfortable grip for everyday hand sanding.
Make a Sanding Block from a Sanding Belt
The main body of this DIY sanding block is a solid wood block sized to fit the sanding belt.
The key is getting the length right so the belt fits snugly once the tension bar is installed.
Start by folding the sanding belt flat and measuring its length.
Then subtract approximately 1/2" from that measurement to determine the length of the wooden block.
This provides room for the tensioning system that holds the belt in place.
One end of the block is rounded over to match the curve of the sanding belt.
The opposite end has a V-shaped notch that accepts a square tension bar.
I also routed finger holds along both sides of the block to make it more comfortable to grip during sanding.
Cut the V-Shaped Notch at the Table Saw
The V-shaped notch is what makes the sanding belt tensioning system work.
Fortunately, it's easy to cut using a table saw.
Set the Blade to 45°
Start by tilting the table saw blade to 45°.
Then make the angled cuts at the end of the block to form the V-shaped notch, as shown in the construction drawing.
The notch should be sized to accept the square tension bar.
When the bar is inserted, it pushes against the sanding belt and holds it snugly around the wooden block.
Because the cuts are made near the end of the workpiece, use a suitable jig or other secure work-holding method to keep your hands clear of the blade.
Install the Sanding Belt and Tension Bar
Once the wooden block is shaped and the notch is complete, installing the sanding belt is straightforward.
Slip the sanding belt over the block, positioning it so the abrasive covers both broad faces.
Then slide the square tension bar into the V-shaped notch.
The bar takes up the slack in the belt and holds it securely against the block.
There's no need for adhesive, screws, or complicated clamping hardware.
When the belt wears out, simply remove the tension bar, slip off the old belt, and install a replacement.
Two Sanding Surfaces for Better Hand Sanding
The biggest advantage of this design is that it provides two usable sanding surfaces.
When one face becomes worn or loaded with sanding dust, you can flip the block over and continue working with the other side.
The broad, flat faces make the block especially useful for smoothing larger surfaces and keeping them level.
The routed finger holds also provide a secure, comfortable grip, making it easier to maintain consistent pressure while sanding.
As with any sanding block, work through progressively finer grits and sand with the grain whenever possible to minimize visible scratches.
A Handy Addition to Your Sanding Tools
You don't need an elaborate design to make a useful shop-made sanding tool.
This double-sided sanding block combines a simple wooden body, a sanding belt, and a square tension bar to create a practical accessory for hand sanding.
It's easy to build, comfortable to use, and provides twice the sanding surface of a conventional single-sided block.
Best of all, replacing the abrasive takes only a few seconds, so you can spend more time working on your project and less time changing sandpaper.
DIY Sanding Blocks: 3 Easy Options for Woodworking
A sanding belt makes a great double-sided sanding block, but it's just one way to turn ordinary shop materials into useful sanding tools.
Discover three more shop-made sanding blocks using scrap wood, dowels, and sandpaper. These simple designs make it easier to smooth flat surfaces, ease sharp edges, and sand inside curves.
EXPLORE DIY SANDING BLOCKS → More Handy Sanding Blocks You Can Make Yourself
