The Restoration Process

The generous plaster cast gifts by the Metropolitan Museum of Art and Yale University to Fairfield University offers its students the opportunity of a lifetime. The condition of the plaster casts upon delivery clearly represented an accumulation of dirt and grime spanning several decades. The first step in restoring the plaster casts was to vacuum the loose dust and dirt off of the stable casts. Luckily, none of the casts received any severe structural damage allowing this initial cleaning process to be carried out. Once the casts had been vacuumed and the loose dust removed, we used Q-tips and cotton cloths to wipe away as much as possible, not only to prepare the piece for further cleaning but to ensure that the exterior layers were stable.

The next step in the cleaning process was to remove as much soot as possible with the use of erasers. A series of erasers were tried and tested, ultimately revealing that the Mars Plastic Eraser (a soft vinyl eraser, typically white) was the most effective. The generic pink eraser was equally effective but was too rough for some of the more detailed, delicate works. Equally effective for squeezing into the hard-to-reach folds of drapery was the use of pencil top erasers. The thin triangular shape allowed for easy reach with minimal damage. As a result, a majority of the cleaning was accomplished in this stage.

The use of cotton rags dampened with distilled water usually removed what the erasers could not. With this method we were able to wipe away dirt from the larger casts as some of them were previously varnished or painted, making it difficult to see initial results from the eraser. Because plaster softens with water, it was important that those pieces without a protective coating be exposed to minimal amounts of this process. The area was first wiped down with the distilled water and then immediately wiped with a dry cloth. No area was wiped twice, to prevent and reduce the risk of damage.

A drop of liquid dish detergent in a dilute solution of distilled water was added to help loosen the stubborn areas. The process was the same, however, after initially wiping the surface with the soapy mixture and cloth, distilled water was then applied to wipe down the surface a second time, minimizing the potential of soap residue.

Using the same methods, we also applied denatured alcohol only to the most stubborn areas. The denatured alcohol broke up any other grime compounds lingering on the piece for easy removal. Again, the alcohol was not left to soak on the piece, it was wiped on and off using either cloth or in some cases, Q-tips.

After sufficient cleaning, the piece was evaluated for any initial discrepancies. With a solution of Weldbond glue and water, we filled minor holes and cracks. This allowed the piece greater stability as well as a more even surface for the gesso application. Some of the pieces presented significantly larger cracks that required patching from the back. In these cases, BIN sealant was first applied to the back, then strips of burlap coated with wet plaster were applied. This process stabilized a few of the casts and protected them from further damage or deterioration.

Once the surface of the casts was cleaned and stabilized, a sealant can be applied. The sealant solution is made with B 72 combined with a solvent. After this stage, a gesso wash can be applied with brushes, rags and sponges. The purpose of this gesso wash is to tone down discoloration or patches of residual paint, yet allow the plaster surface to remain visible. The final step is to combine very small amounts of burnt umber and/or siena to a gesso wash for a nuanced tinting of the surface, applied with natural sponges and dry brushes. The goal in this finishing stage is to give the suggestion of stone without distracting the viewer's attention from the overall appearance of the sculptured surface.

K.M.