http://www.kunsthaus.ch/en/the-collection/conservation/examples-from-the-world-of-art-conservation/auguste-rodin/stage-3/the-substitution-of-the-lowersupport-structure-and-frame/?redirect_url=title%3DPr%3F%3Ft

Kunsthaus Zürich

The substitution of the lower
support structure and frame

The support structure needs to be substituted whilst standing upright and in sections.  This presents several problems as neither the weight, nor its exact distribution or statics are fully known or calculable.
It is necessary to pay attention to an even weight distribution during disassembly in order not to damage the bronze by bending or tearing it.
In order to protect the monument’s previously restored front side from rust chips and sparks originating in the grinding process, tightly fitting welding blankets and plastic tarpaulins are applied.
In a first step, some measures have to be undertaken to provide some load relief within certain parts of the support structure:  hardwood wedges are inserted on the front of the monument whilst jacking up the middle section, which presumably carries most of the weight.  The substitution work begins with the right section, followed by the right supporting elements and the lower middle section, then followed by the left side and its supporting elements, and so forth.  As an example here we show the substitution of the right section and pilaster.

The individual part is disassembled by use of rotary cutting tools and is entirely disconnected from all bronze parts.

The pilaster is screwed on to the plate and any gaps are filled in with steel.

The screws needed in the lower mid section of the bronze and to connect the frame are outfitted with brass washers which carry the bulk of the load.

Still outstanding measures to conserve the bronze back side include substituting the corroded screws, respectively the conservation of their surfaces and the application of a protective coating against the elements and pollutants.

Old support structure (Photo:  F. Forrer)
Old support structure
(Photo: F. Forrer)
Disassembly of the old section (Photo:  K. Mürer)
Disassembly of the old section
(Photo: K. Mürer)
Removed right section (Photo:  F. Forrer)
Removed right section
(Photo: F. Forrer)
New section with frame of the old pilaster (Photo:  F. Forrer)
New section with frame of the old pilaster
(Photo: F. Forrer)
Screw with brass washer (Photo: F.Forrer)
Screw with brass washer
(Photo: F.Forrer)
U-shaped supports with screws connecting to the bronze (Photo: F.Forrer)
U-shaped supports with screws connecting to the bronze
(Photo: F.Forrer)
Assembly of the supporting frame to the bronze (Photo: F.Forrer)
Assembly of the supporting frame to the bronze
(Photo: F.Forrer)