Instead of “how to make a dado without a router” this blog post should have been probably called “How to make a dado without a router or any power tool, or any hand tool”. I needed to make a dado cut while building my ruler marking gauge without using any of those. I was looking for different options and eventually I created a simple sanding jig which helped me to achieve it. Honestly, that was quite a challenge.
Using a trimming router would be probably the best way to make a dado cut. In addition, you could also use a dado plane a chisel or a in some cases a table saw. But what if you really don’t have any of these tools?
I made a simple sanding jig that helped me specifically to make a dado for my ruler marking gauge. The jig could be improved in a few ways but even this simple version served its purpose well. The dados are clean and without ragged edges.
I made this jig from scraps I had in the shop. The jig has a fixed with at the moment but making it adjustable would extend its applicability.
What I used:
Sanding Dado Jig:
Guiding Rails – 2x -Spruce Wood 3,8 x 20 cm
Baseboard – MDF desk – 25,5 x 25,5 x 0,8 cm
Ruler, Wood Glue, Sandpaper (120, 240 grit)
Double-Sided (Carpet) Tape
Making a Sanding Jig for Dados
The principal is simple. The size of the material will determine the width of the cut. I am using a ruler to make a dado of the same width as is the width of the ruler. The jig will allow your to make exact width dados depending on the used material.
Step 1: Cut the baseboard
I started by cutting an MDF board for the base – (25,5 x 25,5 x 0,8 cm). The thickness of the base ensures that it will not sag while sanding. You could even use a thicker plate.
The reason I chose an MDF board is that it is flat and the surface is smooth. That makes it easier for other materials to glide better along it.
Step 2: Attach the guide rails
Next, I attached a 20 cm long strip of spruce wood to the MDF board using screws. The wood piece serves as a guiding rail for the piece that will be sanded.
I measured the necessary distance between the rails and attached the second guide rail to the board.
NOTE: If building the sanding jig over again I would probably use aluminum guide rails instead of spruce wood guide rails. For a quick fix, the wooden rails serve really well but the aluminum ones would also provide a nice slide and in addition better durability.
Also, take into account the height of the rail. The sanded piece is moving between the rails. So ideally, the height should cover the height of the sanded piece plus the height of the piece used for sanding. In my case the ruler.
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Step 3: Attach the sanding piece between the rails
First I attached a double-sided tape on one side of the ruler. I taped sandpaper to it (240 grit) and cut off the sandpaper excess. Attached a double-sided tape on the other side of the ruler and taped the ruler between the guide rails.
The tape will let you temporarily fix the ruler to the board. You can detach it whenever needed. I wouldn’t probably use sandpaper with less than 120 grit since the edges of the dado might end up ragged. Higher grit sandpaper will get you a sharp dado edge.
Step 4: Sand a dado
I placed the piece I wanted to sand between the guide rails and started sanding by pushing back and forth. Keep the speed constant and apply even pressure.
Keep checking on the dado to end up with the right depth. (Keep in mind there is an additional layer of tape and sandpaper).
Check out the edges – nice and clean.
I was nicely surprised by the result – nice sharp edges and equal depth along the dado. It is a very simple jig but serves its purposes really well considering no power tool or hand tool was used.
There is definitely room for improvement. The jig could be adjustable to accommodate pieces of different sizes. Also, a center finder could be added to automatically identify the middle of the piece or a height lock could be added as well to end up with a specific dado depth.