2 ROUTER JOINERY

Sliding Dovetails
by Glen D. Huey

PHOTO BY AL PARRISH

88 SLIDING DOVETAILS
 ⁄"

O ne of the defining features of

17th- and 18th-century furni-
ture is the dovetailed horizontal case
Basic sliding dove-
tail. The simplest
divider. Case dividers are the rails option in sliding
dovetails. The socket
that separate the drawers, or the door or trench requires only
and drawer sections. Attaching these a single pass with the
dividers to a case’s sides using sliding dovetail bit.
dovetails is probably the strongest
way possible to assemble a carcase.
However, reproducing this detail
is daunting to many woodworkers.
Not only is a sliding dovetail seen as
complex joinery, but it can be made
in different ways. The basic sliding
dovetail, shouldered sliding dovetail
and through sliding dovetail (shoul- ⁄"
dered or not) are just a few of the
options. Shouldered sliding
dovetail. This joint
Each type of sliding dovetail adds a shoulder to the
requires a different jig. I’ve used a dovetail and requires
variety of these jigs in my many years you to make a first pass
with a pattern-making
of building reproduction furniture. straight bit. Then the
Some jigs capture the router base ⁄"
dovetail bit (set at the
and are specific to a certain router same depth as on the
joint above) is used to
bit. If you need to use more than one cut the dovetail.
bit (to make a shouldered dovetail,
for example) this can be a problem –
unless you own two identical routers.
Other jigs are as large as the
entire case side, making them hard
to handle and store. But I’ve found a
¾"
better way. Using a ¾" top-bearing
flush-trimming bit (often used for
Through sliding
pattern routing), a ¾" dovetail bit, dovetail. A more
a template guide with a ¾" outside complicated joint, this
diameter and a shop-made straight- is made in three steps.
First the straight bit
edge, any of these joints can be made forms the shoulder,
easily. then the dovetail bit
⁄" shapes the divider
pin. The final dovetail
From Dado to Dovetail socket is hand cut to
To understand how this works, let’s avoid tear-out.
start with a simplified version of the
joint: a dado. With a straightedge
clamped across a cabinet side and a
flush-trimming bit in your router,

T H E U LT I M AT E R O U T E R G U I D E 89
ROUTER JOINERY

you can cut a dado for case dividers end, the trench must extend a little cut is centered in the dado automati-
or web frames. Simply position the further so the square-shouldered tail cally.
straightedge where you want your on the divider will fit.
dado, set the depth of cut on your Through Sliding Dovetails
router and plow it out. The bearing Two-step Shouldered Joints For an even fancier look, you can
on the bit follows your straightedge. A shouldered dovetail is ideal for create through sliding dovetails.
By using a dovetail bit with a casework that uses web frames, These joints allow the end of the
template guide and this same setup, which support drawers. The straight case’s divider to be seen on the out-
you can use the straightedge to make shoulder, which supports the web side of the case.
the basic sliding dovetail shown frame, is cut just as you would cut a Start once again by plowing the
above left. basic dado. dado as explained above. You could
Use a template guide that has the First align your straightedge cut the socket portion of this joint
same outside diameter as your dove- as you did with the basic sliding with a router, but there’s much less
tail bit to make measuring simple. dovetail. With a ¾"-diameter flush- chance of tear-out if you cut the
Next, clamp your straightedge trimming bit in your router, plow socket using a handsaw.
exactly where you want the sliding out the dado to ⁄" deep. Next, take If you go with this hand-tool
dovetail to go. your router with a template guide route, you should first cut the male
Set the proper depth for the bit, and dovetail bit, set it to ⁄" deep portion of the joint (called the tail)
(⁄" in ¾" material, for example) (without moving the straightedge) on the end of your horizontal divider
then rout the dovetail trench or and make the cut into the case side. using the dovetail bit in your router
socket in a little further than the The cut should be a bit longer than table. The process is explained on the
width of the divider. The trench the width of your front divider. next page. Then use the tail to lay out
doesn’t need to extend all the way Thanks to the template guide (and the location of the socket on the case
across the side. But because the keeping the straightedge in one fi xed side.
dovetail trench will have a rounded location), the dovetail portion of this Now you can saw out the socket.

THE STEPS TO A SHOULDERED SLIDING DOVETAIL

Making a shouldered sliding dovetail begins by cutting as the pattern-cutting bit’s bearing collar (in this case 3 ⁄4"),
a dado in the case’s side. This dado is easily made with a it will be necessary to attach the guide first, then insert
pattern-cutting bit and the right jig, which I call a straight- the bit afterward. Because of the identical diameters, the
edge guide. router base can’t be slipped over the bit with the template
The bed of my jig, shown at right, is simply two pieces of guide in place. The guide is the same diameter as the collar
plywood cut slightly longer than the width of the case side, to allow the dovetail to run exactly down the center of the
then glued or screwed together face to face. (Depending dado cut.
on your router and bit, you might need only one thickness.) With the template guide in place and the depth set on
To complete the jig, screw a third block to the underside of the dovetail bit, you’re ready to cut the dovetail socket, as
the straightedge guide to hook it square against the front shown below.
edge of the case side. The hook should be sized so you can With the socket created, it’s time to make the mating
clamp the jig in place without interfering with the base of tail on the end of the drawer divider. Mount the dovetail
the router. As you cut the dado, make sure you move the bit in a router table and run both sides of your divider on
router in the correct direction (against the rotation of the end between the fence and bit. You will need to make a
bit) to keep it tight against the jig. few test passes to get the perfect fit. Note that I’m using
Next, install a template guide in your handheld router a push block behind the divider for safety and to stabilize
and the dovetail bit. I should mention one important the piece during the cut.
detail: To use a template guide that is the same diameter

90 H A L F- B L I N D D O V E TA I L S BY J I G
Orient the saw to match the two tail the width of the case side. If you’re section. Repeat this cut on both ends.
sides, then cut in from the front edge making a shouldered dovetail, allow With the back portion of the tail
the width of the divider. Finally, for the ⁄" shoulder depth in your removed, slide the divider into the
chisel out the waste between your layout. dado in the case and mark, then cut,
saw cuts. The through dovetail is cut with the matching socket.
the height of the tail equal to the
Don’t Forget the Tails! thickness of the case side (if you Whatever Size You Need
To make the mating joinery on the are adding a shoulder, remember to While these techniques work great
dividers (the tails), I use my router allow for the shoulder). with the standard ¾"-thick drawer
table. Use the same dovetail bit you Your through dovetail doesn’t dividers that are common today, they
used to cut the dovetail sockets to need to expose the whole width of also work with other thicknesses
form the tails to ensure that the joint the divider. For example, you can of dividers by using different-sized
fits well. Set the fence to adjust the show only ¾" on the sides if you like. template guides and bits. The guides
size of the tails, cutting on both sides After cutting the tails on both ends are readily available in a wide variety
of the divider. I like to sneak up on of the divider, use a saw to trim the of sizes, including ⁄ " and 1" if you
the final cut to ensure a snug fit. end ¾" back from the front of the need thicker drawer dividers.
Set the bit to cut at the appro- divider on both sides. Then cut from You should consider using sliding
priate height for each joint style. the back of the divider right at the dovetails for any number of wood-
For the basic sliding dovetail, that point where the tail begins from the working tasks. The possibilities are
height should be about two-thirds of divider to remove the unneeded tail endless.

Straightedge guide

Case side
Dado

Front edge hooks over

case side

You can easily rout the tail of the

The first step involves plowing out a simple dado with Use a dovetail bit, to make your shouldered joint on your router table with the
a pattern-cutting bit, shown above. dovetail socket. matching dovetail bit.

T H E U LT I M AT E R O U T E R G U I D E 91