Friday, February 13, 2009
Routine cleaning may benefit Lady Liberty
Now that the Liberty statue in the rotary has been spruced up, what needs to be done to keep it in good condition going forward? Ivan Myjer of the Arlington firm Building and Monument Conservation worked on the statue last June and has since submitted a final report. Carlisle Garden Club Civic Committee member Jane Anderson helped coordinate the project and summarized Myjer’s advice for maintaining the statue, “If we can just wash it off once a year it would take care of a lot.” With this yearly attention, she believes it will be “a long time before a major clean-up is needed again.”
Myjer was paid $3,250 in Community Preservation Act (CPA) funds for the restoration project, which was co-sponsored by the Carlisle Garden Club and the Historical Commission. Town Meeting approved spending up to $4,000 and unused funds will be returned to the CPA historic preservation fund.
The marble statue of the Goddess of Liberty was acquired in 1883 and placed on a granite base inscribed to honor Carlisle veterans of the Civil War. The index finger of the right hand has been missing for many years, but aside from that, the statue has suffered primarily from staining and an accumulation of lichen, moss and algae.
To clean the monument Myjer first used a “biowash” to kill the organisms growing on it, while water and a shampoo-like solution were used to clean the stains. Anderson noted that the DPW provided an ample source of water to rinse the stonework and the Police Department helped with traffic control.
Small fissures in the softer portions of the marble were cleaned out and then repaired with a lime grout. The report states that “special attention was paid to the most weathered portions of the monument, particularly at the upraised proper right hand, the face and top of the crown as well as the fingers of the proper left hand.”
In his report, the stone conservator says that “The marble sculpture is in better condition than many marble sculptures and gravestones of equal age. This probably has to do with the specific properties of the French or Italian marble used to carve the sculpture. However, because all marbles are soluble in acid, the surface will continue to degrade as a result of exposure to rainwater (which has a naturally low pH) as well as the corrosive action of sulfuric acid and nitric acids introduced into the environment by industrial pollutants and car exhaust.”
“At present there are no proven treatments for arresting the acidic deterioration of marble,” says Myjer, and he cautions that until one is found, “the temptation to coat or waterproof the marble should be resisted.” However, he adds that chemical treatment to stop micro-fissuring might be useful at some point.
Myjer states, “It is difficult to predict how long it will take for the biological growths to begin to re-colonize the surface of the weathered marble.” While the treatment should have killed most of what was growing on the stone, “new organisms arrive as wind-borne spores, along with soil and dirt that settle in the cracks, crevices or hollows of the carving.”
“An annual rinsing of the sculpture from the ground with clean water delivered from a hose would be an effective way to slow down the rate of re-colonization. An additional preventative step could include spraying the surface with a biocide such as the Prososco Biowash prior to rinsing it with clean water. If one or both of these steps are completed on an annual basis, the type of cleanings that was completed this past summer will not be required again. If the cleaned surface is not maintained on an annual basis then re-cleaning to remove thicker layers of organic growths will probably be required every three to five years.”
In addition, Myjer suggests the town hire a qualified stone conservator every five years to inspect the marble. “At the same time, a conservator would evaluate the efficacy of the grouts that were applied and identify any additional areas that might require treatment.” ∆
© 2009 The