Naum Gabo
'Spheric Theme' 1969

The sculpture was displayed outdoors in the grounds of the Munch-Museet in Oslo. After some problems with damage to the wires and the surface of the Corten steel, Gabo decided to replace it with a version made in stainless steel, and in 1970 the current version was installed. Sadly, after further damage to the delicate strings, the sculpture was eventually removed to storage.

‘Spheric Theme’ is fabricated so that the curves of the outer shape are made from four semi-circular arcs that are joined in four places using rows of small bolts. The form is held in place with brackets to top and bottom as well as a star-shaped form at the centre. These are black painted stainless steel. The outer edges of the central painted steel section and the inner edges of the curved steel sheet are pierced to allow delicate spring wires to be threaded through the sculpture. After many years on display the stainless steel surfaces were oxidised and streaky with handprints, watermarks and small accretions. Cracks had also developed where the star-shaped element was attached to the steel sheet, possibly due to constant wind vibrations. The black painted surfaces were flaking and degraded with a great deal of paint loss. 

We worked in collaboration with Sculpcons Ltd and the team at Oslo kommune to carry out treatment. Before the damaged wires were removed the complex stringing pattern was carefully documented. The type of wire spring originally used by Gabo was no longer available and had to be custom fabricated. The sculpture is held in tension by bolts; undoing them would cause the metal sheet to fly apart and the form of the sculpture would be lost. It was therefore necessary to construct a supportive wooden framework to hold the sculpture in place whilst we removed the bolts and welded the cracked areas in the central section. 

Tests were carried out to mimic the surface appearance of the matte black paint using a modern paint system that would resist outdoor conditions more effectively. The damaged black paint could then be removed and the central section and brackets repainted.

We carried out further tests to determine the best system to clean and polish the stainless steel surfaces of the sculpture without affecting the original brushed metal finish. Once cleaning was complete the central section of the sculpture was threaded with wire and can now be seen as the artist intended. The restored sculpture is currently displayed in a sheltered area within the atrium of Oslo kommune’s offices in Central Oslo.