Series editors' preface - Wood Tools

464 Conservation of Furniture
(a) (b) (c)
(d) (e) (f)
Figure 10.17 Diagnosing problems with hinges
(a) Correct alignment of butt hinge pivot pin (other methods of fitting butt hinges can be found in Joyce, 1987)
(b) Pivot too far forward – hinge protrudes
(c) Pivot too far back – door can’t be opened properly
(d) Recess for hinge too shallow – door can’t close properly
(e) Screw heads too large – door can’t close properly
(f ) Recess for hinge too deep – door can’t close properly
Shrinkage may produce a clean separation
between components as a result of adhesive
failure, a ragged irregular crack as a result of
cohesive failure of the wood itself or a combination
of the two. It may be desirable in some
cases, such as those with a pictorial or geometric
symmetrical design, to close the gap and
compensate for the change of dimension on
one or both sides. Curved elements in a decorative
veneered or painted design may be
distorted or misaligned if splits are closed.
If shrinkage has occurred and the RH conditions
in which the object is normally kept are
stable, treatment options range from limiting
treatment to stabilizing vulnerable edges
through to closing the split and/or adding material
to compensate for the gap. The focus of
much research has been to develop methods
that bridge the gap but which will not exacer-
bate compression set if RH should rise and the
wood expands. Wherever possible, the surfaces
either side of the fill should be level (Figure
10.15). Approaches to structural fills for
wooden objects have been reviewed by
Podmaniczky (1998). A variety of fill materials
and fillers, including silicone/microballoons,
epoxy/microballoons and wood, have been
examined by Barclay and Grattan (1987),
Grattan and Barclay (1988), and Barclay and
Mathias (1989). Grattan and Barclay (1988)
concluded that fillers with a low modulus of
compression, such as waxes, balsawood and
silicon rubber/microballoon mixtures, are least
likely to cause damage if further movement as
a result of fluctuating RH occurs. Silicone
rubbers may stain and wood may need pretreatment
to avoid this problem. Epoxy
resin/microballoon mixtures may be appropriate