The Half-Blind Dovetail
Joint
- The second kind of
joint that is called a “dovetail
joint” is where the female
recess is cut on the end of one
work piece and only part way
through the thickness of that
work piece forming a socket
into which the male fan shape
cut in the other work piece is
trapped.
Since the joint can only be seen
from the side where the fan
shape is cut, it is most
commonly called a “half
blind” dovetail joint. These
are most often cut by a
dovetail shaped router bit
guided by a template where
the male fan shape is cut with
that work piece held vertically
and the female socket cut with
that work piece held
horizontally.
Often, like with the VS-600,
both parts of the joint can be
cut simultaneously, and the
joints in two sides of a drawer
or box can be set up and cut at
the same time. The manual for
the Festool VS-600 refers to
this as simply a “dovetail
joint”. We will talk a lot more
later about how to do these
joints quickly and accurately.
The Through Dovetail
Joint
- The third kind of
“dovetail” joint is where the
male and female parts of the
joint are cut all the way
through the thickness of each
work piece. This is commonly
called a “through dovetail”
although the Festool VS-600
manual refers to this as an
“open dovetail tenon”. It is a
far more complex and
confusing joint to machine
than either a sliding dovetail
or a half blind dovetail. The
male fan shaped portion of the
joint is normally cut with a
dovetail shaped router bit with
the router guided by a
template with straight sides on
each finger of the template.
The female recess portion of
the joint is normally cut with a
straight router bit guided by a
template where the sides of
each finger are angled at
exactly the same angle
designed into the dovetail
router bit.
The angle machined into the
template and the angle
machined on the router bit
must be exactly the same or
the two halves of the joint
simply will not fit together.
This is one reason I always
recommend using ONLY
router bits manufactured by
the same company that
produces the through dovetail
template.
Nothing can ruin your day
faster than to be frustrated by
the fact that the angle actually
cut by an off brand router bit is
slightly different from how it
is marked, and that is slightly
different from the angle on the
fingers of the template. No
matter how hard you try, you
will never get a good fitting
6
