October 14, 2020

How to Make Simple Rabbet Joints

We’re building a shoeshine box and to do this we need to make some rabbet (not rabbit) joints using a dado blade. There are 2 types of cuts that make grooves in a board

Dado – go across the grain of the board.
Rabbet – the same thing but has a shoulder.

From your boards, figure out which pieces will be for each side, particularly focusing on the top since in this case, that’s what you’re going to see the most.

It’ll be really helpful to have these labeled as you work since they’re essentially the same in appearance and size in this case.

There are many different ways to make rabbet joints, but my favorite is to use dado blades.

To install your dado blade, you will need to remove your throat plate that comes with your saw because it won’t be wide enough to hold all of the blades stacked together, and you’ll need to remove your blade guard too. I actually made my own throat plate for this out of wood! You’ll also need to remove your riving knife for making dado cuts, so don’t forget to put it back on when you’re done.

To install the dado blades you’re going to have 2 blades that look like regular saw blades only they’re smaller diamter. Put on the full size blade first all the way against the arbor.

Then you’re going to have these 2 shims to use as spacers. Then you install the chippers. You’ll need to use the shims first before putting on the chippers to prevent the teeth from the chipper from banging up against the teeth on the blade and breaking them off.

The goal here is the make the blades capable of cutting wider than 3/4″ or at least pretty close to that. You won’t need a shim between the chippers, but between the chipper and the saw blade. When you’re putting them on, just make sure the teeth aren’t banging up against each other as they can break off.

Notice how I have them installed so they aren’t touching the other carbide teeth

Next I’m going to place this thick shim, the necessary shim on all of the carbite chippers then add the last blade. Make sure when you tighten down the blade you are careful not to overtighten.

Give it a quick onceover to make sure no teeth are grinding and that they are all facing the same direction. Then lower the blade and be sure to install your throat plate.

Lower the height of the dado blades to half the height of your board and then run a test, look at the top of the tooth to tell height.

When I cut rabbets I usually like to cut them like this:

The problem with this method is that the board is likely to scrape up against the rip fence, so the way to avoid this is to clamp a board to your rip fence called a sacrificial fence. A scrap of plywood will be your best bet because it needs to be nice and straight.

You never want to make dado or rabbet cuts by hand, always use a gripper of some sort to keep your hands away from the blades.

I’m going to use a scrap board and run it through twice to clean up the cut and check for width.

Next I’m going to take the next panel for the box and check to see if the width of the cut is correct for the size of the board to make sure it sits flush. There should be no overhang.

Now it’s time to cut the rabbets for real on all 4 of the boards from earlier. Here’s the diagram we are using to give us an example of where to make cuts. Be sure to keep your facepieces and hidden pieces in mind here. We will be starting with the front and back boards.

It’s very likely that those rabbets aren’t perfectly flat so you’ll want to sand down any discrepancies to make sure they’re flat and smooth.

You can apply sandpaper to a firm flat surface, like a piece of a block of wood to do this.

Now you can pre-assemble all of the pieces together to see how it will look before gluing. Once I get it all squared up, it should stand up on it’s own!

If you have a strap clamp that will come in handy when assembling. You can also use other clamps. Try not to dent the wood by clamping too tight. Now we can take real-life measurements of the openings to cut the last 2 pieces.

The other thing to keep in mind before cutting is the grain direction, remember where the top of the box will be and what boards will be facing you when it’s finished, because you’ll have to look at it and you don’t want to have different grains going different directions.

To make this last cut I’m just using my rip fence.

I want the board to be a little bit too big so I can really zero it in by shaving a little bit off the sides that need it most. I’ll figure that out by fitting it into the box.

After making a very slight cut I’m now going to try and get a nice, snug fit by pounding this piece in to place. Clamps come in handy for this too!

If for some reason there’s a small gap or something don’t go crazy over it as you probably won’t even see it after everything is finished.

Repeat this process for the other side.

Then all we have to do is take it apart and put it back together. It’s going to work better if we glue the whole thing at once rather than one piece at a time. So I’m unfolding the box so I can quickly put it back together.

When applying glue, I like to just use my finger but if you do this, be sure to spread the glue on both the bottom and side of the rabbet cut so it’s fully covered.