Underbench Cabinet: Dovetailing for Blood! …Part 2
Perhaps
I need to explain the title, "Dovetailing for Blood". In
part, the description comes from a book, "Backgammon for Blood",
by Peter Becker I read about 4 decades ago. It's about taking the
game to the most competitive level. This series of articles is not a
how-to about dovetailing; it is about the strategies I use when
building drawers. I offer them for discussion and your
interest.
This
is the drawer in question.
In the previous article, the
focus was on strategies for connecting the drawer front and drawer
sides via half-blind dovetails. The aim there - and continued here -
is to complete the dovetailing in such as way that the drawer may be
glued up, and dry inside the
drawer case. The advantage of drying inside the drawer case is that a
good fit is assured.
Today the drawer back needs to be
attached with through dovetails.
For
interest, here are the chisels I used: Kiyohisa slicks and Koyamaichi
dovetail.
Noticeable
in the drawer above is that there are no grooves for the drawer
bottom. These will now be added using a plough plane and a sticking
board to hold the work...
The
drawer sides are around 7mm at this stage, with the expectation that
they will end up at 6mm. The inside and outside faces have been
planed. The groove is 3mm deep ...
The
groove in the 18mm thick drawer front is 6mm deep ...
The
drawer back receives a shallow groove ...
Reason?
The
drawers are designed for a tool cabinet. Unlike drawers for the home,
where the backs are lowered, these drawers will have a full rear, in
height, ending at the drawer bottom. We start with drawer backs
exactly the same dimensions as the drawer front. The lower section
needs to be removed. The top of the groove marks this position.
The
waste is removed on the table saw, a smidgeon grace ...
...
and the machine marks then planed away.
It needs to be
stated that drawers are not the same as boxes. While they may both be
dovetailed, the drawer width is determined by width of the drawer
case. It cannot be larger or be smaller. The drawer front and back
are made as a pair, and their dimensions are not permitted to be
altered.
With boxes, one can leave dovetails proud, and
then level them to the sides. Or one may level the sides to the
dovetails. You cannot do this with drawers, especially if the game
plan is to aim for the glued up drawer drying in the drawer case.
Consequently, the dovetails must end up flush with the surface
....
We
move over to dovetailing the rear:
The first step, with 6
drawers of the same height and width, is to make a template for the
spacing of the dovetails.
While
the template stretches across the board, the area of importance is
above the drawer bottom.
Mark out the tails, as usual, but
then flip the board so that you are sawing from the inside of the
drawer ...
Again,
this is not a box. The inside of a drawer is seen, and it is
important to keep the baseline as clean as possible, that is, no
over-sawing.
Similarly, when removing the waste with a
chisel, start with the outside face of the drawer, and finish with
the inside. That way there is less danger of inadvertently chiseling
over the baseline.
Now
... the interesting part comes with transferring tails to pins. This
can make-or-break the drawer.
Here
we see the tail and pin boards aligned. But are they?
A
square shows that the side is out at least 1-2mm at 300mm
(12").
Left
like this, the drawer will not sit flat. It will act as if it has a
twist. Significant efforts will need to be made to align the drawer
in the case. It becomes essential that the side is aligned
accurately. This can be a little fiddly, but a long square helps
considerably ...
At
some point, someone will mention the side-alignment fixture designed
by David Barron. This is a wonderful concept, however it excels at
making boxes and not drawers. Look here ...
The tail and
pin boards are not
aligned at
the square ends (which would enable David's fixture to be used). They
are aligned on the reference side, which is the lower edge of the
drawer sides. You are aligning from the left
side of
these boards ...
Having
transferred and sawn the tails, the bulk of the waste is removed with
a fretsaw (as detailed before). Here is a reminder - first chop out
the waste from the outside face, half way down ...
...
and then complete from the show-inside face.
My preference
is to angle the chisel slightly away and create a "tent"
...
This
is then removed with a slicing paring action, again form each side to
the centre ...
Use
a narrow chisel to pare the ends: having first sawn these away, the
remnants for paring lie above the chisel walls (again discussed in a
previous article) ..
This
is what we are after: flat ...
Dry
fit ...
The
drawer must fit the drawer case ...
It
does, but we are not finished. More in a while ..
Regards
from Perth
Derek
February 2021