DIY Dowel Jig for 2×2 Joinery

See how easy it is to make your own dowel jig for joining 2×2 lumber.

See it All

Below you will find:

• Tool and material list
• video tutorial
• Step-by-step written tutorial with snapshots

About the Jig

I made this jig to do through dowel joinery on a shoe rack tower, as none of my other dowel jigs worked well on 2×2 lumber.

Video Tutorial

Transcript highlights and images are below the video too!
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DIY 2x2 Dowel Jig

Cut Your Wood

On my miter saw, I cut off the factor edge on the end to ensure it was dead square.

Then I used a combination square to accurately mark my wood for 3” and cut it.

Then I marked the next piece and cut it.

Mark Center for Spacer

I’m going to be super honest with you here. It’s not likely that you will get your spacer 100% dead center in this jig unless you’re super lucky.

That’s okay. The jig will still be plenty centered enough to work just fine for through dowel joinery on 2x2s.

And you may want to practice on scrap wood with making Xs and trying to hit it dead square with your center hole punch too.

Hold or clamp your wood pieces butt to face and line them up on the outer left edge as square as you can.

Then mark the center line where they meet.

Use a combination square to mark the diagonals as accurately as you possibly can.

Then use a center punch to mark the intersection of those lines.

Mount for Spacer Hole Drilling

This part does require you to be as precise with your drilling as possible.

I recommend using a drill press.

If you don’t have one, then hopefully you have some other method to keep your drill perfectly perpendicular to the wood.

I have a drill press, but not a drill press vice.

So here’s the setup I eventually used to hold my wood. I’ll show you an alternative with fewer clamps in a moment.

I sandwiched it in between 2 other small 2×4 cutoffs I made when I created my dowel jig prototype.

Here’s another angle on the setup.

I used Irwin quick release clamps on the outer wood.

Here’s the other side.

I used an F clamp for the main piece, as I just like it for tight holds better.

Use whatever clamping methods work best for you.

Drill the Spacer Hole

Here’s my alternative setup that I used on my prototype.

As you can see, I simply clamped all 3 pieces together from the side.

And then I clamped the whole thing to the drill press.

Look at your line up from all angles.

It’s not likely that your 1/2” bit will deflect any, if at all.

But you want to be as accurate with this as possible.

And if you’re cutting through oak, expect to see and smell a bit of smoke.

That’s some hard wood, unlike the pine I was using here.

Mark Wood Blocks to Be Joined

Now it’s time to put our 2 wood blocks together.

And I apologize for the fuzziness on this video.

Place your blocks so that your spacer hole is on the right of the top block.

And line them up carefully.

If you flipped it over, you may want to mark another center line.

On the side opposite your spacer hole, use your center punch to mark 2 points to pre-drill for the screws that will hold the 2 blocks together.

I placed mine near the corners, just over ¼” in.

You want them far enough apart to hold good, but not close enough to the edge to risk splitting it.

Choose Screws and Bit for Pilot Holes

For this project, I used #8 x 2-1/2” wood screws.

This is the right type of screw thread for hardwood. Construction screws are not the right thread type for hardwood.

Be sure you match the screw thread type to the type of wood you are using for this project.

The size of the bit you use for pre-drilling your screw holes will depend on what type of screw you are using.

And the type of screw will depend on the type of wood you are using, as you need different threads for hardwood and softwood.

Drill Pilot Holes to Join Blocks  

Again, precision matters here.

These screws are long and they need to go in straight.

I used the same sandwich setup at the drill press as I did before.

But the one shown here was the simpler setup on my prototype.

Be sure to also countersink for the screw head type that you are using.

Pre Drill Into Second Block

Now you need to extend those pilot holes into the second block.

I used quick release clamps to hold the blocks together and then secure them to the bench.

Hand drilling like this is naturally going to make the holes in the first block a wee bit bigger.

That’s okay, as long as you don’t hollow them out too much.

Just drill as straight as you can. And be super careful not to break that small bit.

And I had to change my clamp configuration to pre-drill that second hole.

As you can see, the holes have been started on the second block.

Trick to Ease Screws into Hardwood

My dad taught me this trick.

When screwing into hardwood, you need a little something to lubricate it.

I prefer candle wax to bar soap, but either will work. Just ensure you get unscented candles so that they have no oils in them.

• Candles are crazy cheap at the dollar store.
• They stay wrapped in their plastic for easy handling.
• They don’t flake off as much as some soaps.
• You don’t have to worry if they get a little wet.

Scrape your screw across the candle to get some wax into the grooves.

You don’t need much, just so it’s loaded.

Then twist it smooth.

Go a little slow until you can get this long screw started squarely.

And just go a little into the second block. Don’t tighten it all the way down yet.

Adjust your clamps if needed.

And then start on the second screw and drive it all the way in.

Then drive the first screw all the way in.

Doing it this way will keep the blocks square.

Remove the Seam in the Spacer

Don’t let the description of the spacer fool you.

There is a seam.

It’s on the inside.

And you’ll need to clear it before you insert it into your block.

Remove the Interior Spacer Seam

Here’s how I secured the spacer.

You may want to add another flat board under this whole setup, like a scrap piece of plywood, so you don’t drill into your bench top.

I got a tight hold on it with a pair of large vice grips.

Then I clamped the vice grips in 2 places to the corner of my bench.

Oil Your Drill Bit

You’ll be grinding metal on metal.

You need a lubricant to help the drill bit cut without causing so much friction, as that causes heat and can weld the 2 pieces of metal together.

Use lightweight machine oil – like 3-in-1 oil.

Do not use WD-40 for this. It evaporates.

Set the torque on your drill down between 6 and 10.

You want the drill to stop spinning if it gets bound. Otherwise, it could jerk and you could get hurt.

Insert the bit and rotate the drill around just a little to spread some of the machine oil on the inside of the spacer.

You can see that I had to turn my torque up a bit so that the drill was still under my control, but so it had enough power to start shaving off the seam.

Hold the drill as straight as you can and apply a little pressure.

Let the bit do the work!

Don’t press hard into it.

You’ll feel when it shaves off the seam.

And you can see that I forgot to put that piece of plywood underneath and left myself a nice memory on my bench.

Check the clearance by hand to ensure your 3/8” bit can glide through the spacer.

Prepare the Spacer to be Inserted

For this part of the project you will need:

• Joined blocks
• Spacer that you smoothed on the inside
• C clamp or other press fit tool
• Epoxy
• Sandpaper
• Gloves
• Shop/paper towel
• Wax paper – optional

That spacer is as smooth as glass.

You need to rough it up a bit to give the epoxy something to bond with.

I used an old piece of sandpaper to scuff it up.

And I chose to go up and down as that way the scratches would line up with the direction I would be inserting the spacer into the wood and not bind.

Prepare the Epoxy

I used Gorilla quick set epoxy that sets up in 5 minutes.

I used a piece of wax paper under this whole project.

Then I squirted out my quick set epoxy into a corner of it.

And then I remembered to put on my gloves.

Mix the epoxy well, and for as long as the package directions say to do it.

Don’t skimp on this process. You need that spacer to bond to the wood block and take spinning drill bit pressure and not come loose.

Spread the epoxy onto the spacer.

You only need a thin layer, but it needs to be covered all over.

Now insert your spacer as squarely as you can, but it doesn’t need to be perfect.

Use your C clamp, or other press fit tool to insert the spacer into the block hole.

As you can see, my C clamp has a metal end on the top. And that’s the end I have next to the spacer where most of the epoxy is likely to leak out.

If your tool has a plastic or rubber edge, you may need to take precautions to ensure the epoxy does not melt it or stick to it.

Wipe everything off immediately.

And yes, that epoxy will permanently stain the wood. It would have to be sanded off and you don’t really want to do that at this point.

And clean your C clamp immediately too, before the epoxy has time to set up.

Same with the epoxy stir stick, as you’ll likely want to use that again.

Cure Time

Read the directions on your epoxy for the proper cure time.

And keep in mind that there is setup time and then fully cured time.

Honestly, I would let this thing sit so that both sides of the spacer can fully dry for a full 24 hours before using it.

That’s It!

Enjoy using your new dowel jig on your 2×2 joinery!