How the Mosaic was Lifted...

In 1990, the Ohio State University in cooperation with the Department of Conservation of the Greek Ministry of Culture, began an expensive and time-consuming conservation process: lifting the mosaic from its current foundation, piecing it back together, and then resetting it in place on a new, stronger concrete foundation.

By clicking on the movie icons below you can download video clips of the actual steps involved in lifting the monochrome mosaic. You will need QuickTime to view the files...

First, individual lines of tesserae were removed. This activity essentially divided the mosaic into numerous panels (148 by the time we were finished!).
Each individual tessera was glued to a strip of material, so that it would not get lost and could eventually be replaced in its exact, original position.
Next the mosaic panels were swept clean. The panels would need to be clear of debris to facilitate the gluing process.
After a careful sweeping, the panels were thoroughly washed to remove any remaining dirt and dust. Again, for glueing purposes, the panels had to be as clean as possible.
Once the panels were clean, a thin gauze was laid down and adhered to the mosaic with fish glue. The fish glue was made from fish parts, and was soluble in water. After this had dried, a strong cloth was also glued to the mosaic, providing a very firm surface for the tesserae.
An individual panel could then be cut away from the remaining mosaic by hammering and chiseling down through the mortar bedding.
After chiseling through the mortar beneath the panels, long iron bars were driven under each panel. These bars were then pried up, effectively separating the panel from the rest of the mosaic.
The individual panel was now detached from the remaining mosaic.
After separation the panel was flipped over, and any remaining mortar was removed from the bottom.
The final product was a panel of tesserae glued to a firm cloth surface. Restoration could now commence, and after its completion, the mosaic was placed back in its original position on a new mortar bedding.