18 ■ POPULAR WOODWORKING
Wedged Mortise & Tenon
3
5
4
to withstand a lot of stress on its
joints, I’m aiming here for a mortise
and tenon without any wiggle room.
Cutting the tenon is pretty
straightforward. I saw the shoulders
fi rst, then rip down the cheeks.
The hardest part in this case was
holding the 6^1 / 2 ' rail for rip-sawing.
I propped it against the bench and
worked across the top corner, just
like when I was resawing walnut re-
cently. I sawed across the end grain
and down the tenon edge near me.
I did both kerfs to that point, then
fl ipped the piece over and continued
down the other edge.
I pared the tenons’ faces with
a smooth plane, tapering them
slightly toward the ends. I cleaned
up right against the shoulder with
a large framing chisel across the
grain. I aimed for a tight fi t just as
the tenon is fi nally all the way home.
At fi rst, I left about 5" of the tenon
extended beyond the bedpost. Then
I test-fi tted the tenon in the mortise
and scribed a line where the tenon
protrudes beyond the post. This
locates the baseline for the wedges
that secure the tenon.
In some cases, I drive the wedge
down along the post, through the
height of the tenon. With this ten-
on being only^3 / 4 " thick, I decided
to drive two wedges across the
post, through the tenon’s thickness.
You may be surprised at how slight
a taper is needed to wedge a joint
like this.
Cutting the wedge-mortises in
the tenons requires careful layout.
The fi rst (and very important) detail
is that the baseline is NOT the line
struck during the test-fi t. Move it
back, toward the tenon’s shoulders.
That way the wedge won’t hit this
baseline and will bear on the bedpost
and the tenon’s end grain. I used an
adjustable bevel to mark the wedges’
slope, then dropped lines with a
square. Check everything before
picking up the tools to make these
mortises, as there’s no going back. I
bored these mortises from the small
side of the taper, then cleaned up
with paring chisels.
To make the tenons, I planed a
small piece of wood to the desired
thickness, then marked out a gang of
wedges this way and that across the
width. Make them longer than you
need them, it’s easy enough to trim
after the fact. After sawing them out,
plane their edges and try to slip them
into the mortises. Aim for a thickness
that eases into place, you want the
pressure to be on the edges of the
wedges, not the faces. Bevel the ends
so they don’t chip when driven home.
As you test fi t the wedges, if one is
snug in one joint, try it on another
before trimming it. When I like the
fi t, I mark all the wedges and joints
so assembly will go smoothly. They
all look the same, but they might not
be interchangeable. PW
Peter Follansbee has been involved in
traditional craft since 1980. Read more
from him on green woodworking, peri-
od tools and other topics at pfollansbee.
wordpress.com.
3 Ripping the tenon is
careful work. It’s not
like I have lots of large
timbers around if some-
thing goes wrong.
4 Make sure the
shoulders are tight, then
scribe this line on both
faces of the tenon.
5 Sawing out wedg-
es that are laid out
fl ip-fl opped across the
width of the blank.