Although the main discussion around the crystal easels was of another order, the official arguments for their removal primarily mentioned tech- nical and safety issues. Now, after a nearly twenty-year absence when they were only used in other places, they are coming back into use at MASP, in a reconstruction that dedicates special attention to those same technical aspects.
Now that the technical issues have been resolved, it will be possible to take a new look at their original aims, effects and formalization—the nearly total dematerialization of the support, paradoxically obtained through a rudimentary technique and from an expressive materiality, a recurrent mechanism in Lina Bo Bardi’s poetics. The crystal easels can be considered as part of the museum’s collection and heritage, not only for their importance in the history of the ways of showing art, but also in light of the intimate link between their origin and that of the spaces conceived by Lina for the MASP building.
The premises and aims for the project of reconstructing the easels were based on extensive research into all of the available documentation rela- ted to them. Most of the material consists of pictures of a prototype and of various configurations of exhibition setups in the museum throughout the span of nearly thirty years that they were used there. With the exception of a sketch by Lina, neither MASP’s documentation center nor that of Insti- tuto Lina Bo e P.M. Bardi contain records of their design, leading us to be- lieve that they were developed in a rather empirical way.
Other relevant sources were a survey and analysis of the various types of surviving ea- sels and, especially, statements concerning the functioning of the system furnished by people who participated in the setup of previous exhibitions that used them, who are still members of the museum’s staff.
The system—a very simple one—consists of a heavy concrete base for providing stability, along with a sturdy pane of glass, which holds the artwork at a position where it can be observed. The glass is attached to the base by a wooden wedge and a bolt, which applies pressure to the glass, holding it firmly in place. Where the glass contacts the wood and the concrete there is a protective rubber liner.
Even though some changes were made to the design of the pieces, the original materials and functioning principle were rigorously main- tained. The main adjustments were made with the aim of strengthening the concrete cubes; adding the possibility of leveling the set; allowing for the full function of the wedge with a more effective and durable tightening system; standardization of the height of the drilled holes so that artworks can be switched interchangeably from one glass pane to another (in the original version; each glass pane was paired with a single artwork; with holes custom-drilled especially for it); increasing the protection of the edges of the glass panes to avoid breakage and to reduce undesirable vibrations, with the use of adequate damping.
The various pieces that make up the system and the modifications that were made are described below.
Steel reinforcing was added to the interior of the concrete cube to prevent breakage. Moreover, a piece of stainless steel was embedded in the concrete to hold the lower nut and to ensure the integrity of the internal canal through which the bolt passes, especially at the edges. The bottom of the base was provided with recesses for the insertion of shims which are necessary to level the set on the museum’s uneven floor, substituting the improvised wooden shims used previously.
The original sizes and proportions were maintained, along with the use of shapes made with unfinished wood, and the use of concrete in a conventional outline, to maintain the original aspect.
The solid wooden wedge received only a recess to hold the head of the bolt, and a widening of the central channel, to allow for the movement of the bolt when it is tightened. In the original pieces, the contradiction between the necessarily diagonal movement of the wedge and the vertical position of the bolt inevitably led to its bending.
Pieces for Attaching the Wedge to the Block, and Tightening It
The original system used a single bolt, whose head was under the block, in direct contact with the concrete, with the bolt’s thread protruding above the upper surface of the wooden wedge. On top of the wedge, a simple nut and washer were used to tighten the system. The new design inverted the position of the bolt, with the head in the upper part, in a recess in the wooden wedge, and the nut near the floor. A washer with an oblong hole allows the bolt to be tightened without damaging the wood, while allowing for the movement of the bolt to absorb the differ- ences of alignment caused by the diagonal movement of the wedge. On the bottom, the bolt is housed in a recess created in the concrete and is fitted with a neoprene washer.
The glass panes have the original specifications, though with a higher quality, due to developments in fabrication methods and production con- trol. They are made of 10 mm thick tempered glass in four widths (0.75 m,
1.00 m, 1.50 m and 2.20 m, the latter one never produced although it was in the original sketch), all with the same height (2.40 m).
The holes are all drilled at a standard height and at a standard width, which varies according to the width of the glass.
Fastening of the Works to the Glass: Sleeves, Bolts and Bars
The biggest change to the system involves the attachment of the works to the glass. In order to make the attachment system more versatile, allow- ing for different artworks to be mounted on the same support, a stain- less-steel bar was introduced, attached to wooden backframes installed on all the works to be shown. With an oblong hole in the same standard position as the holes drilled in the glass, the bar allows the artwork to be leveled quickly and securely. To protect the edges of the holes in the glass and to ensure a firmer attachment, stainless steel sleeves were pro- duced to hold the shaft of the bolt, covered with nylon protection, thus avoiding direct contact between the steel and the glass.
Shims and Protective Liners
The material of the rubber protective liners for the glass was substituted by a more durable and stronger elastomeric material, since the origi- nal rubber dried out and gradually lost its elasticity. Shims of various heights were also made from the same material. These pieces, placed under the base in recesses made on the bottom of the concrete block, allow the set to be leveled, while simultaneously absorbing vibrations that could be harmful to the artworks. The hardness and degree of the material’s vibrational absorption—normally used in industrial an- ti-vibration devices—was determined through the use of specialized measurements to identify the vibration frequencies that predominate within the concrete floor of the museum’s second-story exhibition area.
text by Martin Corullon