Series editors' preface - Wood Tools

of the stock and a rule of thumb for seasoning
converted timber is one year for each inch
(25 mm) in thickness. End grain should be
sealed with wax or a similar material to prevent
splits.
Another criteria in the selection of wood for
repairs may be the degree of off-gassing of
volatile organic acids such as acetic acid. Many
materials associated with wooden furniture, e.g.
paper and metals, will be damaged by acidic
conditions. As a general rule, unseasoned, kiln
dried wood, and those woods with a pH lower
than 5, should be avoided if adjacent material
is susceptible to damage (Table 10.1).
10.1.4 Transferring shapes, profiles and
measurements
As with cabinetmaking, it is essential that
measurements are accurate. In addition, the
conservator should be faithful to the tolerances
of the original object. Screw lockable dividers
can be used to transfer profile of carved or
curved components quickly and easily and
reduce the risk of inaccurate measurements
(Figure 10.1). This will provide a working
template for replacement of an irretrievably
broken component.
10.1.5 Making the repair piece
Consideration must be given to the size, shape
and orientation of the repair before shaping
begins. In some cases the first step may be to
make the surface that will be jointed before
commencing general shaping – for example,
when scarfing new wood to the broken leg of
a tripod table. In other cases, such as preparing
false tenons, the process is one of planing
the wood to set dimensions. As is the case
when joints are first manufactured, accurate
measurements and good cabinetmaking skills
are required. Repairs should closely mate with
the original to provide a strong joint for the
final repair. It may be necessary to incorporate
excess material for shaping and cramping,
which is cut away after the repair is fixed into
place.
10.1.6 Fitting the repair to the object
A structural repair to an object should be
securely attached and provide the best possi-
Principles of conserving and repairing wooden furniture 439
Figure 10.1 Transferring shapes, profiles and
measurements. A piece of card is cramped so that it is
parallel to the joint edge of the component. Dividers
are used to transfer the profile of the component to the
card. Once the first outline is completed, measurements
of the thickness of the component can be taken with
spring screw callipers and transferred to the card. A
template made in this way is usually sufficient for both
faces of a component such as a cabriole leg, but if in
doubt both faces can be checked against the template
ble aesthetic and mechanical integration of
new material with the old. This requires that
the surface profile of new and old should
match closely and gluing surfaces should be
clean and sound. This is more readily achieved
when the gluing surfaces are straight and flat
although there may be situations where shaped
surfaces are necessary.
The first stage of fitting a repair is to prepare
the surfaces that are to be jointed or adhered.
This may involve removing some original
material to provide a level surface for the joint
or matching the repair to an uneven surface.
Rather than taking a dogmatic stance to either
approach it is more realistic to consider each
case within the constraints imposed by
commonly accepted ethical guidelines. Whilst
these generally assume a presumption against