Manual of Purpose-Made Woodworking Joinery

Dovetail joints 37

personalized by individual, experienced woodworkers,
resulting in interesting variations. My own slant on
dovetailing techniques is as follows:
Whether the material is softwood or hardwood,
I use a combination of an ordinary HB pencil (for
marking face- side and face- edge marks), a carpenter’s
oval- or rectangular- shaped pencil (for marking the
shoulder- and centre- lines, dovetails and pins) and
a marking knife for the intermittent shoulder marks
and (on hardwood jobs) for marking the pin- positions
between the dovetails. The carpenter’s pencil, as illus-
trated, has to be shaved well back on each wide- side to
produce a very sharp (knife- like) skewed chisel- edge.
The marking knife, also with a skewed cutting edge,
has a sharp 20 to 25° ground and honed bevel on each
side or on one side only. The double bevel allows for
left- hand or right- hand use and suits users who prefer
to lean the knife over, as I do, (against the edge of a
try square) to gain better visual appraisal of being on
target. However, marking knives with a single bevelled
edge have the advantage of being sharper – because
the ground and honed bevel is only 20 to 25°, whereas
a double bevel (2 × 20 to 25°) produces a less inci-
sive edge of 40 to 50° – and single bevelled knives
(if you regrind one and have a handed pair) are ideal
for laying flat and marking the pins between closely-
spaced dovetails.

Through dovetails

The dovetailing procedure outlined here is related
to the making of a box with four equal- length sides
measuring, say, 450 × 145 × 12mm (perhaps to be
clad with 4mm plywood and then sawn continu-
ously around the glued and cleaned- up, closed box
to produce a lid). Having prepared the timber to
the sectional sizes and marked the selected surfaces
and edges with face- side and face- edge marks, the
four pieces must be cut carefully to length + 2mm
(452mm). They are now ready to be marked with joint
shoulder- lines of 13mm (12mm + 1mm) to be squared
around each end. The 1mm allowance is for initial
end- grain planing and eventual cleaning- up.

One of the ways that I do this is to cramp the four

carefully- lined- up pieces together (face- to- face) in the

vice or with G- cramps, check that the lined- up edges

and ends are square, then measure 13mm in from each

end and very lightly knife- mark squared shoulder lines

across the four face- edges. The pieces are then released

and separated into pairs: two for dovetailing, which

can be marked with a (D) and two to receive dovetail-

sockets and pins, which can be marked with a (P).

On the two (D) pieces, I reinforce the faint ‘datum’

edge- marks with more incisive knifing and transfer

them squarely and, again, incisively across the inner

face- sides and the rear- edges – but not the remain-

ing unmarked face- sides. These last two shoulder lines

must be marked with a sharp carpenter’s pencil.

On the two (P) pieces, the very lightly- knifed

‘datum’ marks on the face- edges (being only datum

lines that will not be shouldered) must remain without

deeper knifing, but they are used to transfer deeper-

knifed, square shoulder- lines across the inner face-

sides and – as on the (D) pieces – pencilled shoulder

lines across the face- sides marked with a sharp

carpenter’s pencil.

Next, on the face of one (D) piece only, mark a

pencilled centre line at each end across the width –

between the shoulder and the end – equal to half the

timber’s thickness (6mm) up from the two shoulder

lines. This is for setting out the dovetails with dividers.

End- grain planing

Figure 3.32: The initial end- grain planing – men-

tioned previously – has to be done at this stage to

create smooth, even (and square) surfaces for the

seating of the dovetail template and the try square;

and to give a clearer definition of the setting out

marks made on the end grain. Even so, sometimes,

especially on dark- coloured hardwoods, white chalk is

rubbed into the end grain to highlight the pencil- or

knife- marks. The planing (shooting) of the end grain

can be done with a block plane or a finely- set smooth-

ing plane (my preferred method), but a developed skill

is needed to avoid spelching (breaking away the end

Figure 3.31 (a) A carpenter’s pencil converted to a
joiner’s knife- like pencil (b) A typical single bevelled- edge
marking knife.

Component in position

(b)

Figure 3.32 A shooting board.

Medium

(b)

(a)