fine tools

dovetailed
Shoulder Plane
Make an heirloom tool and learn the secret to creating
double dovetails in metal — it’s easier than you think.

I’ve always been fascinated by old, metal hand planes. make the pins look like tails to create the double dove-
Especially ones that were made using dovetails to join tails. I’ll explain more about this later.
the sides of the plane with the sole, like the shoulder When building your own plane, you’ll need to
plane in the photo above. If you look carefully, you’ll decide how to go about locking the iron (or blade) in
see that they’re really “double” dovetails. Both the place. I could have used a simple wedge to do this. But
sides and the sole have flared “tails.” Now this seems I wanted to be able to easily and accurately fine-tune
like it would be impossible to put together. But these the depth of cut. The solution is really pretty simple. I
dovetails are cut almost the same way as regular dove- used just a few commonly available hardware items.
tails. The tails are cut into the brass sides and the pins This allows you to adjust this plane to make paper-thin
are cut into the steel sole. But there’s a little trick to shavings for tight-fitting joints.

32 ShopNotes No. 88
 Materials & Hardware Exploded
Infill and Wedge (cut from same piece) 1/2 x 4 - 8 (Rgh.)
(1) 1/4"- 28 x 6" Threaded Brass Rod
View Details
OVERALL DIMENSIONS:
(5) 3/16" x 1" Brass Rod WEDGE SECURES 11/ "W x 21/ "H x 6"L (plane body only)
16 4
BLADE TO BED FOR
(2) 1/8" x 2" - 6" Brass Sheet Stock CHATTER-FREE CUTS
(1) 3/16" x 1" - 8" Low-Carbon Steel Stock
(1) 1" Brass Lamp Shade Riser
(1) 11/16" Shoulder Plane Iron SLOT IN PLANE IRON
ENGAGES COLLAR ON
ADJUSTER KNOB

WOOD INFILL
THICKNESS
DETERMINES WIDTH OF ADJUSTER KNOB IS
FINISHED PLANE “TURNED” ON THE
DRILL PRESS FROM
BRASS LAMP SHADE
RISER

THREADED BRASS
ROD ALLOWS FOR
FINE DEPTH-OF-CUT EASED EDGES
ADJUSTMENT MAKE FOR
A COMFORTABLE
GRIP
STEEL NUT IS
TAPPED TO ACCEPT
THREADED ROD 20º BED ANGLE IS
LARGE OPENING DESIGNED FOR
ALLOWS SHAVINGS CUTTING
TO ESCAPE WITHOUT END GRAIN
CLOGGING

STEEL SOLE IS
LAPPED FLAT AND
AND SQUARE TO TIGHT MOUTH HELPS
SIDES FOR PREVENT TEAROUT
ACCURATE CUTS
BRASS ROD
IS USED TO
RIVET SIDES
TOGETHER

BRASS SIDES ARE

DOVETAILED TO SOLE

ACTUAL SIZE
(CROSS SECTION)

WEDGE

FRONT INFILL

REAR INFILL

www.ShopNotes.com 33
 FIGURE
building the 1
Plane Body
The shoulder plane is made from a
pair of brass sides and two steel sole
pieces that wrap around the wood
infill pieces and wedge. You can see
what I’m talking about in Figure 1.
The box below shows the step-
by-step process to layout and cut
the dovetails. But there a few other
things I want to mention.
Making the Sides. The first
thing to do is make the brass sides
since all the other pieces are made
to fit them. You can turn to page 40
for an overview of the tools and
techniques for working with metal.
Since the sides are identical, you rate layout lines using layout dye that’ll leave about 1/16" of brass to
can file and drill both at the same and a sharp scribe. peen over later when you lock the
time, as shown in the box below. Laying it Out. The first impor- sides to the two sole pieces.
Using carpet tape to fasten them tant layout line you’ll need is the The next step establishes a ref-
together, make sure to align one one to mark the bottom of the erence line for the bed angle
long edge and one short edge of dovetails. I made this line 1/4" from (Figure 1). The purpose of the bed
each blank flush with the other. the bottom edge as you can see in is to provide support for the plane
Now you can begin to make accu- Figure 1. Since the sole is 3/16" thick, iron when it’s wedged in place.

Step-by Step: Filing Dovetails

Filing the double dovetails isn’t as layout line, just daub a little more
hard as you might think. It’ll take layout fluid on and scribe it again.
some time and patience to get every- Take Your Time. As you
thing to fit right, though. They start file closer to your layout
out like ordinary dovetails. But later line, take a little more care.
on you’ll turn them into double And you might want to
dovetails. Here is what you need to switch to a finer file. The
know to get started and get great- more time you take at this Pieces to the Puzzle.
looking double dovetail joints. point to get nice, straight lines You’ll work on the two brass sides at the
Clean Layout Lines. Just like and sharp corners, the better the same time, making your layout lines on one
you do in woodworking, you’ll be dovetail joints will look in the end. side. The two steel sole pieces form the mouth.
“working to a line.” This means
you’ll need sharp layout lines for
the best results. Layout dye and a
sharp scribe make it easy to mark
your lines in one pass (Step 1). This
will guarantee a thin, precise line
you can work to while filing.
Use Guide Blocks. When you’re
filing, the file can skate across the
metal, especially as you start the
cut. To help guide my file, I clamp
some scrap wood blocks along my
layout lines (Step 2). And if you do
happen to accidentally remove a
1 Use a protractor and scribe to lay out the
tails on the brass sides. I used an angle
of 15° for looks and strength.
2 A square file quickly removes most of
the waste. Then finish up the dovetails
with triangular and needle files (inset).

34 ShopNotes No. 88
 FIGURE
You’ll use the layout line when you
position the sole piece on the brass
2
sides. The bed angle on the sole
should line up with this layout line.
Tight, Square Mouth. There’s
one thing to point out when it
comes time to cut and assemble the
two blanks for the sole. To take a
nice, clean shaving from end grain,
the mouth opening needs to be
pretty narrow. I shoot for about 1/16"
(or a bit less) for the mouth (Fig. 2).
If it’s too narrow, you can always
open it up as I’ll show you later.
Infill Blank. Before making the
sole, I chose a nice piece of hard-
wood for the infill. (I used padauk.)
Step 4 below shows you how to use
your plane iron to determine the
final thickness of the infill.
Filing for Tight Joints. With the
layout lines in place and the infill
blank in hand, you can follow the
steps below to complete the sides
and make the two sole pieces. I
found it helpful to stop filing occa-
sionally and test-fit the pieces until
I got a nice, tight fit between them.

3 I used a 3/4 "-dia. hole saw and 7/16"-dia.

bit to rough out the mouth opening.
Then drill 3/16"-dia. holes for the rivets.
4 Using the plane iron as a gauge, plane
the infill stock down until the plane
sides and infill match the width of the iron.
5 After centering the infill blank on the
sole piece, you can scribe the
baselines for the dovetails.

6 Use a wood guide, cut to match the

bed angle, to file the 20° bevel on one
end of the long sole blank.
7 With a spacer block, hold the two sole
blanks between the sides. Then
scribe the pin profile on the sole blanks.
8 Once you rough out the waste to form
the pins (like you did on the tails),
finish up with fine needle files for a tight fit.

www.ShopNotes.com 35
 assembling the 3
FIGURE

Body &
Infill
At this point, the two sides and sole
pieces should fit together nicely. But
there’s one more small step. To cre-
ate the double dovetail look, you
need to file a “splay” in each bottom
corner of the pins on the sole pieces.
This leaves a gap or pocket between
the pins and the tails on
the sides (detail ‘a’).
Then, when you peen
the brass sides to the sole,
the brass fills in these little pockets,
{ Double
creating a locked joint. The box
Dovetails. The
below shows you how to do this,
simple trick to
along with the other steps you will
a.
getting great-
need to do to complete the body.
looking double
Adjuster. Now that you have the short length of threaded brass rod, One end has a threaded hole that
dovetails is some
“shell” of the plane done, you can and a shop-made, steel nut. you’ll use for the threaded brass
careful filing.
move on to the infill and adjuster The knob is made from a lamp rod. The other end has a stud that
mechanism. The adjuster is made part called a lamp shade riser you can cut off. The top photo on
from three pieces. There’s a knob, a (margin photo on opposite page). the next page shows how I shaped

Step-by Step:
Peening
Peening the brass tails into the steel
sole pins is what holds the plane
body together. You actually “flow”
the brass into the joints. The trick to
making the double dovetail, though,
is in filing the “splays” in the sole
pieces, as shown in Step 1. All you’re
doing here is removing a small tri-
angular section of material from the
1 A triangular file is used to create the 15°
“pockets” on the sole pins. This will make
them look like tails after peening.
3 Use files to finish forming the mouth
to its final shape. But don’t file below
the layout line for the bed angle.
bottom corner of the pin.
Peening Tips. Once that’s done,
it’s time to peen the pieces together.
There are some tricks to getting the
best results. One is to have a solid
surface to work on. I ended up
using the peening buck (next page)
on the concrete floor in my shop.
Another trick is to make carefully
directed hammer blows. It doesn’t
take a lot of force to move the brass
into the joints. It’ll look like a mess,
but don’t worry. You can take care
of that when you file it smooth.
2 The object is to force the brass into the
gaps in the sole. Work on a solid surface
and take your time.
4 Mark and cut the infill pieces and drill
the rivet holes. The rear infill should
line up with the bed angle on the sole.

36 ShopNotes No. 88
the knob on the drill press. The
important thing is for the “collar”
4 a.
on the knob to fit into the adjust-
ment slot on the plane iron. For fine
adjustments, it should have a close
fit without being too loose.
The shaft is a short length of 1/4"-
28 threaded brass rod. The knob is
threaded onto one end and the
other end of the rod engages a
shop-made steel nut in the infill.
The drawing on the previous page
shows how it goes together.
I made the nut for the adjuster
from a piece of leftover steel I used { “Turning” the Knob. Chuck the
for the sole. It’s drilled and tapped knob into the drill press and use
with a 1/4"-28 thread. files to shape it. The collar should
Rear Infill. The rear infill is a tri- fit the slot in the plane iron.
angular piece that houses the
adjuster and forms the bed for the sure it lines up with the bed angle the mouth of the plane complete, as
plane iron. You need to drill a hole on the sole. Then you can trim the detailed in the box below.
for the adjustment rod and cut a end flush with the brass sides. Rivets. The final step is to add
slot for the nut. I found it was Front Infill. The front infill is the rivets that lock the sides and
easier to do all this before cutting angled to match the shape of the infill in place. I used a dab of epoxy
the infill piece to shape (Figure 4). wedge and hold it in place. (You’ll to hold the infill pieces in place { Shade Riser. A
After that, you can cut the 20° bed make the wedge later). I roughed then drilled the rivet holes. After brass lamp part is
angle to match the sole and insert out the shape of the infill piece but peening the rivets in place, they “turned” into the
the infill into the body. Just make didn’t do any final work until I had can be filed flush with the sides. adjuster knob.

Peening Buck
When peening the sides to the sole, I pieces have oversized holes for a pair of
had trouble with the pieces shifting. lag screws. A bolt clamps the side pieces
So I came up with this “peening buck” of the plane tight. Then you can tighten
to help hold the pieces securely. the lag screws down. Finally, place the
The base and two side pieces are assembly on a firm surface and start
made from 11/2"-thick hardwood. The peening using firm, direct blows.
center support is planed to the same
thickness as the infill and is glued

5 Scrap laminate with holes allows the

rivets to “mushroom” on the bottom.
Remove it when peening the other side.
and screwed securely to the base.
To hold the plane body in place
while you’re peening, the two side

6 A flat file smooths the sides and sole.

Just be careful not to round over the
edges of the plane body.

www.ShopNotes.com 37
 adding the final 5
OVERVIEW

Details
Now that you’ve got the body of the
plane assembled, you can make the
wedge and add a few last details.
Wedge. The wedge holds the
plane iron securely in the plane. I
made mine from the same stock as
the infill. But you could use a dif-
ferent or contrasting hardwood for
a “custom” look.
What’s important is to shape the
wedge so that it forces the plane
iron tight against the bed, espe-
cially at the mouth. So some careful
fitting is in order here.
You can use the drawings at right
Pattern
to rough out the shape of the
wedge. Then it’s just a matter of
fine-tuning the fit as you go. The
goal here is that the “nose” of the
wedge should end up just slightly
behind the bevel on the plane iron
(see photo below). If the wedge is
too tight to move that far forward,
you can remove a little material at a Tuning. At this point your plane fine-tune the width of the plane
time from the bottom edge, is almost functional. But there are a body so that the iron projects a little
checking the fit as you work. Then few details to take care of before from each side. This lets the plane
you can sand the finger notches giving it a workout (see box remove shavings all the way into
smooth and ease the edges. below). For starters, you need to the corner of a joint.

Tuning Your Shoulder Plane

Now is the time to double check the width of At the same time, you want to lap the
the sole against the plane iron. You can use sides and sole so they’re square. Put some
fine-cutting flat files and sandpaper to lap adhesive-backed sandpaper on your table
the sides of the plane to a smooth finish. The saw and run the plane along the rip fence to
goal, besides a great appearance, is to have keep the sides square with the sole.
the edges of the plane iron projecting past Finally, check that the mouth is square to
the sides of the plane body just a hair. This the sides and the bed is flat. The iron should
helps the plane cut right into corners. sit tight against the bed without any gaps.

Width
of plane
body is slightly Fine-tuning Lapping Lapping while using the
narrower than the the mouth opening. the sole flat. rip fence as a guide.
width of the iron.

38 ShopNotes No. 88
 Chamfer and Polish. Traditional < Stopped
shoulder planes had a small Chamfers. Use a
chamfer on the edges. Besides flat file to form
adding a nice detail, it makes the the chamfers on
plane more comfortable to use. A the edges of
file makes quick work of adding the plane.
the chamfers (upper right photo).
To finish up, I used some abra-
sive pads to polish the brass (lower
right photo). A little oil gives a nice < Final Polish.
finish on the infill and wedge. Use abrasive
Once you’ve done this, you’re pads and wet/dry
ready to give the plane a try. The sandpaper to
box below shows how to use your give the plane a
shoulder plane. After taking some polished look.
time to get it set up just right, you’ll
be amazed at the results.

Using the 1. Tenons

Plane
Shoulder planes get their name from
their ability to slice the end grain on
a tenon shoulder (Figure 1). They’re
designed for fine-tuning joinery.
Since the plane iron is a hair wider
than the plane, it can get “into a cor-
ner” for professional results.
Tenons. When I want a perfect fit
with mortise and tenon joinery, a
shoulder plane can’t be beat. I use it
{ Shoulder Work. The shoulder plane excels { Smooth Cheeks. Remove saw marks and
all the time to trim the cheeks of a
at slicing the end grain of a tenon shoulder. For sneak up on a snug fit using the shoulder
tenon to get a snug fit in the mor-
best results and to prevent tearout, work from plane. Shave equal amounts from both cheeks
tise. And a couple of cuts on the
both sides toward the center. to keep the tenon centered on the workpiece.
tenon shoulders gives me nice,
tight-fitting joints.
Rabbets and Dadoes. As you 2. Rabbets 3. Dadoes & Grooves
can see in Figures 2 and 3, a
shoulder plane is also ideal for fine-
tuning rabbets and dadoes. You
can fine-tune the thickness of a
rabbet by sneaking up on the fit.
And it works just as well for
cleaning up the shoulder.
A dado blade is a great way to
cut grooves and dadoes. But there’s
a problem. The bottom of a dado or
groove can be rough. But a
shoulder plane makes it easy to
clean up the bottom of the dado. { Width and Depth. Clean up the face of a { Clean Bottoms. A pass or two with a
Since the shoulder plane excels rabbet and fine-tune the depth using the shoulder plane is all it takes to get rid of saw
at working into corners, it works shoulder plane as shown. Flip it on its side to marks and create a smooth bottom in dadoes,
great on lap joints, too. dress up the shoulder of the rabbet. grooves, and lap joints.

www.ShopNotes.com 39