Conservator's Corner: it’s a small mosaic

Some areas are carved out from the cast plaster background reinforced with a fibrous component; other sections have an internal wire support with the plaster cast on top; and still others appear to have been constructed with walls and supports that were removed once the plaster was cured. Remnants of the walls remain adhered to some areas. Several areas are cast with a pigmented or toned plaster.

Surface treatment for some of the raised mosaic-like design elements include adding in sand, mica, and clear and amber-colored glass fragments. It appears that some of these treatments took place when the plaster was wet, others were applied to the top of cured plaster, and others were included in a mix of plaster when the particular design element was cast.

During a conservation assessment prior to exhibition, it was determined that the object needed treatment and stabilization before it could be displayed. The plaster was in good structural condition with minor abrasion and flaking occurring along the edges and corners. The surface was covered with loose surface dirt, scattered areas of embedded dirt, and grime that adhered to the surface and embedded in the pores of the plaster. Uneven discoloration resulted in a “halo” effect around the outer side and top edges of the front of the object.

There were areas where the mosaic-like sections of the surface design were loose and cracked—where the glass and sand surface treatments were unstable and in danger of becoming lost.

To prepare the object for display, we carried out various methods of treatment. First, the surface was cleaned with light brushing and a low-suction vacuum to ensure that inclusions were not dislodged. The background surface and stable raised areas with inclusions were surface-cleaned further with a Staedtler Mars Plastic Eraser. The surface was then vacuumed again to remove eraser residue.

Areas of loose inclusions, glass, mica, and other surface decoration were stabilized by preconsolidation with Aquazol 500 (poly-2-ethyl-oxazoline) in isopropanol. Once dry, the area was the consolidated with 5% B-72 (ethyl methacrylate) in acetone. The combination of these two adhesive systems allowed for the areas to be stabilized without discoloring the surface.

Japanese paper impregnated with an acrylic adhesive was used to support the areas of exposed internal wire. This was used in the area of the missing plaster in the flag shape at the top of the artwork and along the edge of the exposed wire of the reddish/brown plaster loss near the bottom of the artwork. Once the paper fill had dried on the flag shape, the surface was covered with Flugger’s Acrylic Spackle. This particular acrylic spackle (butyl methacrylate and calcium carbonate) was chosen because it provided a fine, smooth surface that can be easily finished with sandpaper resulting in a surface that is ready to take any paint or coating that needs to be applied.

The area was then shaped with fine sand paper and toned with Gamblin Conservation Colors. Gamblin Conservation Colors are made up of a low molecular weight resin and were chosen for use in this treatment because they retain their solubility in mild solvents that are safe for the conservator to work with and safe for the original media on the object.  They remain easily reversible over time, are stable upon aging, and have excellent optical and working properties that allow conservators ease in addressing different painted styles and techniques.  In the case of this mosaic, the combination of the chosen spackle and Gamblin Conservation Colors resulted in fills that were stable, easily reversible, and visually integrated well with the original materials.

The two sections that were bent out of plane were heated with an air gun and then bent back into position. Once moved, the break edges near the background were covered with Japanese paper. The beauty of the fill described allows the object to be presented how it was originally intended to be seen; however, the fills can be easily removed.

To improve the overall appearance, stain reduction was carried out using paper pulp as a poultice with distilled water and ethanol—repeated until the stain could no longer be reduced.

The object is held in the frame by its own weight. There were no visible indications of mechanical attachments and the object lifts slightly when pressure is placed on the back. The frame itself appears to be bowing slightly along the edges due to the weight of the object and it was highly recommended that the object not be exhibited in the upright position. When displayed in the Mary Blair exhibition, the object was displayed on a slant with a support that carried the weight of the plaster. The support, built and created by the team of preparators at The Walt Disney Family Museum, was also able to reinforce the object when it was returned to its permanent storage location while not on display.

Senior Conservator of 3D Objects

The Walt Disney Family Museum

Image sources (in order of appearance):

• Mary Blair, “it’s a small world” façade mosaic, c. 1964; collection of the Walt Disney Family Foundation; © Disney

• Mary Blair, “it’s a small world” façade mosaic before treatment, c. 1964; collection of the Walt Disney Family Foundation; © Disney

• Mary Blair, “it’s a small world” façade mosaic close-up before treatment, c. 1964; collection of the Walt Disney Family Foundation; © Disney

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