Series editors' preface - Wood Tools

11.2 Mechanical cleaning
Mechanical cleaning relies on the physical
displacement of dirt. It causes no shrinkage or
swelling of the surface and, depending on the
object, may present a low risk of displaced dirt
being absorbed into a porous surface. It
requires no toxic chemicals, although dust
may be hazardous. Mechanical cleaning
techniques include dusting, cleaving, abrasion
and dry cleaning. Ultrasonics have been used
to clean metal objects and lasers to remove
corrosion products and dirt from metals,
mineralized layers from stained glass and
organic layers from terracotta but neither have
found wide application to date in furniture
conservation. Strictly speaking, laser cleaning
is not mechanical but rather photothermal or
photochemical, and affects both the physical
and chemical properties of dirt (Cooper, 1998).
11.2.1 Dusting
Dust should be removed before undertaking
further cleaning (Shelly, 1987). Dust is
airborne particulate matter that collects on an
object’s surface and is not bound to the
substrate or itself. Dust is an aesthetic problem
as well as being potentially harmful to the
object. Regular dust removal will increase the
stability and longevity of objects and their
coatings. In some cases the abrasive effect of
repeated dusting on delicate decorative
surfaces, such as gilded wood, may cause
significant damage. Where possible environmental
controls should be used to prevent the
Principles of cleaning 501
Figure 11.5 Removing dust
from a painted and gilded
leather panel using a soft
bristle brush and low power
vacuum cleaner
ingress and accumulation of dust.
Dusting should pick up and remove dust
rather than merely displacing it within the
same environment. Dust can be removed
using a dusting cloth (e.g. varnished table
tops), soft natural bristle brush (marquetry,
boulle or gilded surfaces) or vacuum cleaner
(thick deposits of dust). Feather dusters are
not recommended. Dusting cloths can be
evaluated using Perspex to assess whether,
after numerous dustings, the dust has been
removed, deposits left behind and if the
Perspex remains free from scratches.
Eighteenth century documents indicate that
brushes were commonly used to dust furniture,
frames and interior architecture (Balston,
1956). Dust dislodged in this way should be
captured with a cloth or vacuum cleaner. A
fine nylon mesh stretched over the nozzle can
be used to prevent any loose parts being
sucked into the vacuum cleaner (Figure 11.5).
An established routine of dust removal should
be part of general housekeeping practice.
11.2.2 Cleaving
Cleaving may be used to remove brittle dirt,
metal corrosion products or an unwanted
coating from an underlying surface that is
undamaged and comparatively strong.
Successful cleaving exploits the mechanism
that causes layers to flake, that is, strong
cohesive properties within a layer combined
with weak adhesive properties between layers.
This technique avoids the risks associated with
solvent or aqueous cleaning.