members of cradles for easier removal, for example.^44 This procedure
could prevent greater stress to the painting from unnecessary tool work.
Structural treatments of large panels make great demands on a
conservator and can take a long time. Assuming that they have equal abili-
ties, one conservator usually takes at least twice as long as two, and the
demands on stamina are doubled. A team benefits from improved safety
and morale, and its members can help one another in making decisions,
thereby achieving quicker and better results.Access and control
Easy access is an advantage for structural work. Access is more difficult
with larger panels since the conservator must move around the panel. If
the panel is horizontal, the conservator must find some means of reaching
the work area, which is often in the middle of the panel. It is important to
establish a comfortable position, since the work may be of long duration
or require sustained precise and safe manipulation of tools (Fig. 13).
Horizontal support of such a large, thin, heavy panel as the Mengs
presents some problems with regard to treatment procedures and stress
distributions in the panel during extensive, prolonged structural work.
Concern arose that warp movement would be restrained by the panel’s
own weight if it were laid horizontally, causing detrimental bending stress.
It is difficult to judge the effect of such warp restraint, especially
in larger panels. For example, it was anticipated that once the balsa and
wax-resin were removed from the Mengs, a different curvature would
ensue. Laid horizontally, the panel would almost certainly have warped
away from a table surface. The suspended weight would have caused bend-
ing around the supporting fulcrum(s), with a risk of breakage at the weak-
ened joints or in worm-damaged areas. Therefore, it was considered
undesirable to treat such a panel horizontally before adequate structural
consolidation was achieved.
Alignment and rejoining are generally more difficult for larger
panels than for smaller ones. Suitable temporary supports and apparatus
must be available for operations such as rejoining. The approach must464 Brewer
Figure 13
The conservator, left, kneeling on a bridge
used to gain access to the back ofa large
panel laid horizontally for structural treat-
ment of the wooden support.