Series editors' preface - Wood Tools

(1991) reported that stronger bonds were
formed when adhesive was applied to the
support fabric rather than the leather. The
adhesive should be applied as a continuous
coat. Although Selm recommended a dot pattern
for upholstery leathers and other threedimensional
surfaces, in practice such
discontinuous application often fails. Many
conservators prefer to apply acrylic emulsions
(e.g. Lascaux 360 HV: 498 HV 1:3) adhesive to
the backing material and allow the diluent to
evaporate. The film may be reactivated with
solvent and pressed onto the leather and moderate
heat may be used to improve the adhesive
bond. This technique will ensure a good
adhesive bond but minimize adhesive penetration
of the leather and may be particularly useful
for spot repairs on vulnerable or damaged
leathers.
Beva 371 film or solution can be useful for
large areas, such as panels, is easy to apply
and has good tack. Solutions of Beva can be
pigmented to match the leather. Paraloid B72
may be useful for adhering small flakes or for
small structural repairs. Solutions should have
a high resin content (up to 50%) and may utilize
faster evaporating solvents to limit the penetration
of the adhesive into the leather.
Non-leather infills Often damage to leather
surfaces may be too small or irregular to fill
with leather. The infill material should be flexible
and chemically stable. Pigmented natural
waxes such beeswax or carnauba wax have
been used in the past for leather to infill losses
in leather which cannot flex and is not in use.
Natural waxes have several disadvantages,
including their acidity and a propensity to hold
dust. Mixtures with a high proportion of
beeswax have a low softening point. Beva 371
has been used as an alternative to these natural
materials (Figure 16.9). In all cases it may be
difficult to remove all residues and any accretions
on the leather usually prevent the adhesion
of subsequent non-wax fills. Pre-sealing
the leather may lead to solidification of the
structure unless a very flexible material is used
with minimal penetration. Selm (1991) reported
success using a formulation based on Encryl E,
an acrylic emulsion based on ethyl and butyl
acrylates, a wax emulsion, thickener and
microballoons. Beva 371 film, though less easy
to apply, also produced satisfactory results.
Conserving other materials II 735
Nieuwenhuizen (1998) discussed the use of
Beva 371 or Paraloid F10 bulked with glass
microspheres. Non-leather infills may be colour
matched to the surrounding surface using a
(a)
(b)
Figure 16.9 Non-leather infills
(a) Filling a gap in eighteenth-century gilt leather, from
Levens Hall, Cumbria, using hot-melt pigmented Beva
371. (b) Cleaning excess infill from the seat of a
seventeenth-century chair