ACI: Opus Sectile

Since Sant' Imbenia had marble opus sectile fragments which needed to be cleaned, our class was split into groups. Some worked on fresco pieces and others were in the marble lab. The marble tiles were soaked in tubs of water with the mild detergent and biocide. Andreina, a conservationist (and Roberto's wife), described the process of scrubbing off dirt with a toothbrush before taking it to the table to remove any hardened material.

Andreina and Chiara instructing us on marble cleaning

Here is Andreina's link: http://www.cca-roma.org/en/node/317

We continued the process of gently removing dirt either by brush and the cleaning solution, or by using a scalpel to very gently scrape stubborn build up from the marble. Francesca made sure we were holding our scalpels the correct way. If you could hear the scraping, it was too rough and could leave scratches on the surface.

Opus sectile

 

 

Marble duty.

Lindsay worked on this huge piece for days, it was a beast!

Some pieces would need to be put together again, like the fresco.

Others had more of a tangible pattern.

Marble variations.

Shannon (Grove City College) and Gage with 'zanzaras.'

If the calcium or mud deposits were too hard for the scalpel, we got to use the the pneumatic drill. Chiara said they called this zanzara (mosquito in Italian), because of the 'eeeeeeeeeeee' sound it made. We all wanted to use the zanzara because it was so satisfying to see little chunks of dirt fly off.
Often the tiles still needed a good soak to loosen up centuries of dirt. Roberto and his crew had invented a nebulizer, which emits a fine but constant mist onto the marble. CCA had used this method while conserving the triumphal arch of Septimius Severus in the Roman Forum:

http://www.cca-roma.org/en/node/443

The marble tiles would sit for hours under the spray, then we would scrub them with toothbrushes. It sounds easy enough but it was grueling. Some of the stuff would not come off no matter how much energy we put into it!