The strongest and most permanent joint made
in carpentry and cabinet-making, where pieces of wood are
fastened together at right angles, is the dovetail.
When made in some of its most approved and
perfected forms, it is equal in neatness and artistic finish
to the miter joint. The miter is a comparatively neater
method of joining wood at an angle, but the dovetail
possesses the greatest possible strength.
It is generally employed in articles made of
thin materials, such, for instance, as drawers, boxes,
chests, etc. If we examine a dovetailed box, we observe that
it consists of six pieces, or sides, four of which arc
interlaced, or dovetailed together at the corners, forming a
rigid frame-work. This is shown in Fig. 1.
When properly put together, the joint formed
by the two pieces A and B is strengthened and braced by
these of C and D. The rigidity of the box is of course still
further increased by attaching the bottom, which may be done
by means of screws, or glue and screws may be both employed.
There is an advantage in the employment of
the latter, for if the dovetails should be somewhat loosely
fitted, or the glue loses it adhesive power, the screws will
prevent any disposition of the four sides "to rack."
When we wish to have the lid of considerable
depth, and fastened together by dovetails, the box is made
sufficiently deep to form both box and cover. The top and
bottom pieces are then added.
The six pieces so joined have the appearance
of a rectangular block or cube. A saw is employed to
separate the cover, or lid, from the bottom portion.
This method has the advantage of saving some
labor in dovetailing. It insures the exact agreement in size
and form of box and cover. It would be somewhat difficult to
effect this were they separately made.
This would especially be the case in making such
articles as desks and writing-cases.
In all boxes where
the bottom and lid are made together, the line of division
is marked on the four exterior sides. One of the dovetail
pins is placed on that line. This pin should be about twice
as wide as the others. When divided in forming the cover,
either part is then of the size of the others.
In order to have the cover and box show a
miter joint, the dovetail and joint pin are made to a miter;
whereas, if the pin were left square, or made as usual, the
box when cut open would show the rectangular lines of the
pin and dovetail. The top and bottom of the box may be
fitted in various ways.
They may be glued, or otherwise fastened, on
the square edges of its sides. They may be rebated; or, to
cause a more finished appearance, they may be both rebated
In Fig. 2, the common dovetail joint is
shown, in which the dovetails and pins are seen upon both
When the grain of the wood of the parts
joined together runs in the same direction, such parts will
expand and contract equally, should they be equally moist
and dry. This expansion or contraction can then take place
without injury to the work.
In order to affect this, it is advisable to
make the work from the same board, or from pieces of boards
of the same quality of timber, and having come as near as
may be from the same relative position in the logs from
which they were sawn. This can be very readily ascertained
by an examination of the ends of the pieces, the curvature
or configuration of the grain furnishing the desired
If the pieces of work have the grain running
in contrary directions, as seen in Fig. 3, it is evident
that the portion D would entirely prevent the expansion of
C, and the restraint would cause injury to the joint.