Cut Accurate and Clean Rabbets

When making the cut in two stages, the first cut defines both the width and depth of your joint. Keep your work tight against the fence.

Fixing the Two-step Process
There also is a way to modify the two-step method on the table saw to make it work well for beginners or people uncomfortable with balancing pieces on edge. The trick is a featherboard. (The word “featherboard” doesn’t really do it justice. In our shop, we call it the “motherboard.”)

The “motherboard,” shown in the photos below, needs to press the work against the rip fence right over the blade, so it looks a little different than the one used with the dado stack. This “motherboard” is used only on the second pass.

The first pass defines the width and the depth of the rabbet. Use a saw blade with teeth that are flat on top, such as a ripping blade. A crosscut blade has teeth that score the work like a knife to cleanly remove the wood fibers; this will produce “V”-shaped channels in your work. Other blades, such as those with a triple-chip grind, will create even more problems, so stick with a rip blade.

To set the rip fence, measure from the outside or left edge of the teeth to the rip fence until you get the desired width of your rabbet. Lock the fence down. Then use your 6″ rule to set the blade height so it equals the depth of the rabbet. Again, marking the highest projection of your saw blade’s teeth on your saw’s throat plate will save you hundreds of test cuts per year.

Make a test cut with the work flat on the saw’s table, as shown in the photo below left. If you like, you can use a featherboard to hold the work flat on the table, similar to the way I did it with the dado stack setup shown on page 10.

This featherboard, which holds the work steady and against the fence, is the key to rabbeting on the table saw in two steps.

With your first cut complete, set up your saw to remove the rest of the waste from the rabbet. The critical dimension is the distance between the fence and the blade. In essence, this distance is the amount of wood you want to remain on your piece when the joint is complete. For example: You want to cut a rabbet that’s 1⁄4″  deep in a 3⁄4″-thick piece of wood. To make the second pass, you should set your fence so there’s exactly 1⁄2″  between the blade and the fence. When you set the blade’s height, adjust it until it trims away the waste but no higher. Your first cut already defined the corner of the rabbet.

It’s important that the waste falls to the outside of the blade. If the waste gets trapped between the blade and fence it will shoot back at you when it is cut. This can be less than ideal, depending on where you’re standing.
The other important point here is that you should either make or invest in a zero-clearance throat insert for your table saw. When you balance your parts on edge for this second pass, you want them to ride on as much table surface as possible. The stock throat insert that comes with most saws is too wide for this job.

Set up your featherboard so it presses the work against the fence but above the blade. It should allow the work to pass through the blade but keep it firmly against the fence. With the featherboard set, the cut is reasonably safe: The board will not tend to tip and the blade is buried safely in the work.

And the Winner is …

The “motherboard” keeps everything in place during the second pass. The result is a clean and accurate rabbet.

I’ve cut hundreds of rabbets using both of these setups and I generally prefer using the dado stack method because it has one saw setup and the cut is made in a single pass.

I also like being able to use our overarm guard during the cut, as well as work with the parts flat on the table at all times. But if you don’t have a dado stack (good ones start at about $90), the two-step method is a sound alternative.

We decided to find out which of these techniques some beginning woodworkers preferred – sometimes people who are new to the craft are more intimidated by a certain technique than veterans. After a day of cutting rabbets both ways, the two beginning woodworkers in our workshop were able to make amazingly accurate rabbets using both techniques.

The only notable difference was that the dado-stack method required a little more upper body strength to keep the work to the table – though  the beginners were enamored with the simplicity of using just one pass. The two-step method required a bit more finesse, one more setup and a little math. I tend to avoid math when possible, so my preference was no real surprise.