While circular saws are typically relegated to the role of making quick cuts in lumber and trimming plywood sheeting down to size, there’s actually a lot more you can do with these versatile tools. Creating simple joints like dadoes is one of those woodworking tasks that is typically accomplished with a table saw or router – but can also be accomplished with a circular saw and a little patience.
If you’re looking for a picture-perfect joint, then you’re probably better off using a table saw or router, but if functionality and convenience are what you’re after, then a circular saw will get the job done.
Let’s take a closer look at how to make dado joints with a circular saw – so you’ll be able to do some simple joinery without any fancy tools.
Tools & Materials
- Circular saw with a fine-toothed blade
- Pencil, marker, or grease pen
- Hammer and chisel
- Rough grit sandpaper
- Scrap wood (for guide)
- Wood clamps
How to Make Dadoes with a Circular Saw – Guide
Step 1: Measure and Mark Dado Joint
The first thing you’ll need to make dado joints with a circular saw is to measure and mark the area you’ll be cutting into with a marker or pencil.
You can use the piece of wood your cutting the dado for as a template to sketch the perimeter of the dado joint.
Step 2: Build Guide
A rough guide made out of scrap wood will make cutting out the dado a little simpler – and will prevent you from accidentally cutting outside the intended area. There are a few different ways to do this, but the simplest is to fashion two guide fences that fit on either side of the dado and can be clamped to the workpiece.
Keep the width of each side of the circular saw’s shoe in mind when building each guide, as the shoe is longer on one side than it is on the other. After you’ve built the guides, clamp them in place, and then check to see if the saw blade is lining up with the lines you sketched before.
Step 3: Make a Series of Cuts
Before you start making any cuts, make sure the saw blade is set to the right depth. Next, make the initial perimeter cuts on either side of the dado. Allow for the blade width when making the outside cuts. These are the most important ones, so you’ll want to make sure they’re completely accurate.
If you don’t want to make a custom guide, you can use a speed square to guide your initial cuts.
Then, make a series of cuts every 1/8” to 1/4” along the width of the dado. Try to make sure the shoe stays flat on the cutting surface as you do this, as you can cut remove too much material with the saw kerf if you tilt the shoe while you’re cutting.
This process will create a lot of sawdust and waste material, so it’s probably a good idea to keep a shop vac or vacuum on hand.
Step 4: Clean out the Remaining Material
There are a number of different ways to remove the remaining material left after making the cuts. If the dado you’re making is on the narrow side, you can simply slide the saw blade back and forth between each side until all of the remaining wood is gone.
If the dado is on the wider side, a hammer and chisel can make removing the remaining material and cleaning up the joint a breeze. First, use the hammer to tap out as much material as possible. Then flip it over and use the claw to remove any remaining wood chips.
Lastly, use a sharp chisel to clean up the joint and remove any remaining bits of wood. Be careful not to gouge too deep and remove too much material.
Step 5: Check for Fit
Now, take the two parts of the workpiece and check to see how they fit together. They should fit snuggly, but you shouldn’t have to force them together.
If the fit is too snug, use some rough bit sandpaper or a chisel to knock down the inside of the dado until it fits. Then, attach the two pieces of wood with wood glue and fasteners, and presto – job done