Series editors' preface - Wood Tools

(i)
(ii)
(a)
Figure 10.11 Dismantling joints
(a) Bench dogs (one in the end vice or the work
bench) are positioned next to the joints on the object
(i). The end vice is then slowly opened to force the
joints apart (ii). Softening blocks should be used to
prevent bruising the surface of original components.
Pressure should be applied gradually and it may help
break the adhesive bond if the joint is alternately
opened and then closed. (b) Dismantling dovetail joints.
The component with the pins (e.g. a drawer front) is
held vertically, leaving the component with the tails
(e.g. the drawer side) parallel to, and just above the
surface of, the workbench. A white rubber mallet may
be used to strike the wood immediately adjacent to the
joints so that the force of the blow is directed straight
down the joint lines (ii). The further away from the
joint such force is applied, the greater the risk of
damage (iii)
shoulder of the joint. Small wedges may be
inserted at the shoulder of the tenon from both
sides. By carefully moving the wedges toward
each other a shearing force is applied, which
aids in separating the joint. Metal cramps, in
which the direction of the heads can be
reversed, may be used to provide continuous
pressure at the joints. Similarly, bench dogs on
a workbench may be used on the mortise and
tenon joints of smaller objects, such as chairs
(Figure 10.11a).
Principles of conserving and repairing wooden furniture 457
(ii)
(i)
(iii)
(b)
Where fox-wedged tenons are encountered,
the joint should be drawn apart as far as possible
and a saw used to cut down to the upper
wedge. This will allow the joint to be dismantled,
but will necessitate repair to the tenon
before the joint can be reassembled.
Dovetail joints may be dismantled by hammering
the joint apart (Figure 10.11b). Scoring the
glue lines of the joint may prevent breakout as
the components separate. Attempts to wiggle the
joint apart should be avoided as this will crush
the wood fibres and damage the joint.
Glue blocks may be removed using a chisel
as a wedge. The chisel is placed onto the glue
line and struck sharply with a mallet. Any clean
splinters that remain glued to the surface may
be left in place to help position the block
when it is reglued into its original place.