Half-blind dovetails are a traditional choice for drawer construction. The interlocking pins and tails create a strong mechanical joint, while the drawer front conceals the joinery from view. And with a router and a half-blind dovetail jig, you can cut both halves of the joint in a single setup.
The actual routing goes quickly. The challenge is understanding how your jig works and adjusting it so the finished joint fits properly. A small change in bit height, template position, or workpiece alignment can make a noticeable difference.
I'll walk through the two common styles of half-blind dovetail jig, explain the setup process, and show how to make test cuts before routing the actual drawer parts.
Understanding Half-Blind Dovetail Jigs
At first glance, the dovetail jigs in woodworking catalogs can look quite different. But many common half-blind jigs use one of two basic systems to control the cut.
Both hold the drawer front and side in position while a router, fitted with a dovetail bit and guide bushing, follows the fingers of a template. The main difference is how each jig limits the depth of the sockets.
Template-Controlled Dovetail Jigs
On one style of jig, the guide bushing follows the template slot until it reaches the end. That stopping point establishes how far the router can travel into the workpiece and, in turn, controls the socket depth.
The template's position is therefore an important part of the setup. Follow the manufacturer's instructions for positioning it relative to the end of the upper workpiece.
Fence-Controlled Dovetail Jigs
The other style uses an adjustable fence to limit the router's travel. As you move the router into a template slot, its base contacts the fence, establishing the socket depth. The guide bushing still follows the template fingers, but the fence determines how far the cutter travels.
I've found that this style can take a little more adjustment during the initial setup. Once it's dialed in, though, it produces the same clean, accurately fitted half-blind dovetails.
Choose the Right Dovetail Template and Spacing
The template does more than guide the router. Its finger spacing also determines the arrangement of the pins and tails along the height of the drawer.
Many half-blind dovetail templates are designed to cut approximately 1/2"-wide dovetails on 7/8" centers. Other jigs use 1" or 1-1/8" spacing. Woodsmith commonly uses the 7/8" spacing for its projects.
Why does this matter? For a symmetrical joint, you want approximately a half pin at both the top and bottom of the drawer. Planning the drawer height around your template's spacing helps you achieve that balanced appearance.
The template material is another consideration. I prefer a metal template because it feels rigid and secure as the router moves across it. A plastic template can work well, too, but it may benefit from additional support.
A couple of scrap pieces placed in the jig can support the template and help the clamping bars grip the workpieces more evenly.
How to Set Up a Half-Blind Dovetail Jig
Before making a cut, I take time to understand how the jig registers the workpieces and controls the router. The following setup sequence is based on a fence-style dovetail jig, but the overall approach is similar for other models.
Position the Workpieces and Set the Stops
Start by preparing flat, square test pieces that match the width and thickness of the drawer parts. Position the pieces in the jig according to the manufacturer's instructions and secure them beneath the clamping bars.
Adjust the workpiece stops so the parts register consistently. On a drawer or box, half the joints are cut at the left side of the jig and half at the right, so you'll need to establish the corresponding stop at the other end as well.
Adjust the Fence or Template
On a fence-style jig, position the adjustable fence to establish the socket depth. On a template-controlled jig, position the template itself according to the specified measurement.
Don't assume the setup is correct simply because the parts appear to line up. With the router switched off, make a dry run through the template to verify that the bit, bushing, and router base will clear the jig and travel as intended.
Install the Correct Guide Bushing and Dovetail Bit
Install the guide bushing and dovetail bit specified for your jig. The bit angle, diameter, and bushing size must match the template system.
For the jigs discussed here, the original instructions suggest an initial cutting depth of approximately 1/2" to 9/16". Treat that as a starting point for these particular setups, not a universal setting for every dovetail jig. Check your manufacturer's instructions before making adjustments.
Make Test Cuts Before Routing the Drawer Parts
With the jig set up, it's time to make a test joint. This is where you'll find out whether the settings are correct.
Use scrap that's the same width and thickness as the actual drawer parts. You can reuse the test pieces by cutting off their ends between adjustments.
Step 1: Make a Light Scoring Pass
To reduce chipout along the inside edge of the tail board, begin with a light scoring pass across the front of the workpiece. For the jig shown, this pass travels from right to left.
This is a backrouting operation, so keep the cut shallow and maintain firm control of the router. Follow the routing directions for your particular jig.
Step 2: Rout the Pins and Tails
After scoring the edge, guide the router in and out of the template slots, working from left to right. Keep the router base flat against the template as you move through each finger.
Before removing the workpieces, make sure every pin and socket has been routed cleanly. If necessary, remove the template after the router has stopped to inspect the cuts.
Step 3: Check the Joint Fit
Remove the test pieces and assemble the joint. Don't be surprised if it needs an adjustment on the first try.
The goal is a snug fit that starts with hand pressure and closes with a few light mallet taps. If the joint is too tight or too loose, make a small adjustment to the bit height and cut another test joint.
Once the fit is right, you're ready to rout the actual drawer parts.
Keep the Drawer Parts Organized While Routing
A half-blind dovetail jig cuts mating parts together, so it's important to keep track of which drawer side belongs with each end of the front and back.
I like to label the pieces before routing. That way, I can keep the parts oriented correctly as I move from the left side of the jig to the right.
Taking a moment to label the stock is especially helpful when you're making several drawers at once.
Troubleshooting Half-Blind Dovetail Fit
Even with careful setup, you may need to adjust the jig to get the fit just right. The key is to change one setting at a time, then make another test cut.
These adjustments apply to the jig configuration described in this article. Other dovetail systems may use different controls or adjustment directions, so consult your jig's instructions before changing the setup.
For a more detailed guide to diagnosing joint-fit problems, see Dovetail Jig Troubleshooting: Fix Loose Joints, Tearout & Misalignment.
Make Your Dovetail Jig Easier to Use
Once you've learned how to set up your jig, a dedicated workstation can make repeated dovetail cuts more comfortable and consistent.
Our Portable Dovetail Jig Workcenter raises the jig to a convenient working height and includes support bars to help keep workpieces properly positioned. Fold-down wings give you a place to set the router between cuts, and a built-in drawer stores the jig, templates, and accessories when you're finished.
The workcenter folds up for compact storage, making it a practical upgrade even if you don't have room for a permanent dovetail station.
Start with the Setup, Then Let the Jig Do the Work
Cutting half-blind dovetails with a router is a straightforward process once you understand how your jig controls the cut. Start with accurately prepared stock, follow the manufacturer's setup instructions, and make test cuts before working on your drawer parts.
Take your time adjusting the fit and keep the pieces organized as you rout. With the jig dialed in, you'll be able to produce strong, attractive dovetail joints quickly and consistently.
For additional advice on drawer sizing, workholding, routing technique, and assembly, see our 12 Tips for Perfect Dovetailed Drawers.
