I
f you’re anything like me, and
as you’re reading this magazine
there’s a good chance you are, then
you probably share more than a
passing interest in joinery. There
are numerous methods to join wood,
each one with a number of variations
to cover things like work efficiency,
increased strength and decoration,
or any combination thereof.Wedged tenons
The focus of this article is the wedged,
through mortise and tenon. Perhaps
with the exception of through dovetails,
there aren’t many other joints that say
‘handcrafted’ like one of these.More specifically the focus here is on
tenons, particularly the kerfs for the
wedges and the effect they have on
the tenon. The method of wedging
can be executed in many ways, and
like other woodworking topics the
preferences can be divisive, but is
one method better than another?Enter the fox
There’s a variation of the mortise and
tenon called the fox wedged tenon.
Term four last year at Handsome &
Co, where I teach, involved taking
my students through a small project
which incorporated this little used
variation of a mortise and tenon.The fox wedge is somewhat of an
academic joint, often described in
all the text books but little used.
Although accuracy is an important
part of all good joinery, the fox wedge
takes this to a new level of exactitude.It is not a joint that can be tested
in the usual sense and any error in
making the joint itself can result in
failure, as once the joint starts to go
together it is practically irreversible.Having had no prior experience of the
joint and needing to teach it to my
students I set about testing the joint to
determine the correct shape and length
of wedge and corresponding kerf.The results were shared on my
Instagram page and attracted many
comments, mostly about the kerfs for
the wedges and the ‘best’ method of
cutting them to avoid them splitting the
tenon. I took note of all the suggestions
shared as well as the textbook methods
and then asked myself: what really is
the best way to wedge a tenon?Five ways
All told there are five different
methods of cutting a kerf for a wedged
through tenon. The first four have a
flared mortise that corresponds to the
wedge. First up, and of the English
tradition from my training, is a tight
mortise top and bottom for the first
6–8mm and kerfs cut parallel to the
tenon edges (photo 1). The tight
shoulders are designed to prevent
any splits occurring from the wedges
being hammered into the kerfs.Method two requires two small holes
to be drilled at the bottom of each
kerf (photo 2). The theory here is
that the holes prevent the kerf from
splitting by transferring the stress
of the wedge around the hole.http://www.woodreview.com.au 81TECHNIQUEThe Thin Edge
of the Wedge
Liam Thomas tests five ways of wedging
through mortise and tenon joints.4