The Structural Conservation of Panel Paintings

Because of the inherent weakness of any end-grain bond (espe-

cially with hide glue), it was necessary to pare away only the tongue of

theaddition that overlapped the original panel and the 1 mm lip (Fig. 6c).

Then, when the addition was rocked gently, the brittle hide glue fractured

neatly along the joint without disturbing the original panel.

Close examination of the Washington panel seemed to indicate that the

abrasion around the edges of the fragments had been caused largely by

an attempt to level uneven surfaces afterthe fragments had been glued in

place (Fig. 3). Again, the initial idea here was to separate the fragments

and reposition them while causing as small an alteration to the existing

structure as possible.

The cradle, applied by Stephen Pichetto in 1944,^2 was typical of

the method he almost invariably employed (Figs. 7, 8). He thinned the

panel to approximately 5 mm and then laminated it to a mahogany panel

of 1 cm thickness oriented in the same grain direction. He then “neatened”

the ragged edge of the original poplar panel by the addition of a very

thinmahogany band around the perimeter to match the laminated layer

(Figs. 8, 9). A cradle was then attached; it consisted of mahogany members

oriented in the same grain direction as the panel, with maple crosspieces.

The plan was to dismantle only the section of cradle behind the

fragments and then to attach a platform(extending from the two wide

lobes on the left and right of the cradle) on which to position the frag-

ments and reconstruct the lunette (Fig. 7).

Two crosspieces at the lower edge were removed, and the

mahogany cradle members were sawn through and pared away. The joint

line was then marked precisely on the reverse and cut about halfway

through the mahogany laminate. The sawcut was made perpendicular to

the picture plane, and some additional mahogany was then further pared

away on the fragment side to form a V-shaped opening, which enabled a

better viewofthe bottom of the cut (Fig. 10). By repetition of this

process, sawing and carving slowly advanced the cut without the risk of

cutting into the original poplar.

Removal of the

Washington Additions

346 Bisacca

Figure 6a–c
Metropolitan panel prior to intervention.
Note (a) the extremely thin lip of the groove
section toward the back of the panel, and
(b) the presumed thickness of the Metropolitan
panel at the time the addition was added; the
dotted line indicates the thickness at the time
the cradle was applied. After removal of the
cradle (c), the shaded area was carved away by
hand, leaving only one weak, end-grain bond
between the addition and the original panel.

a

b

c