34.1 Work in Progress - The weakness of the Moai


The weakness of the Moai

The fixed gaze into blank space, the mysterious origins and` the idea of solitude linked with the Easter Island, and the strip of remote inhabited land, far from any other offshoot of civilization: all combine to impart to the Moai a sense of eternity. The truth, however, is quite different: the stone, a very porous volcanic tuff, suffers from degradation with surface detachment due to wind and salty air along with the harmful effects of a powerful lichen attack. The Chilean authorities (National Center for Conservation and Restoration of Chile - CNCR), is well aware of the situation, they had already conducted a series of studies, but the interventions that had alternated since the 60’s were not entirely satisfactory, it was just below the biological profile.

Thus there is a need to carry out a consolidating and protective treatment, with a particular attention to the re-growth of microorganisms.  

The Chilean Council of National Monuments entrusted the preliminary study to the Lorenzo de` Medici school, in the person of Professor Lorenzo Casamenti, with the special permission to be able to carry fragments out of the Moai Island for analysis. These were conducted in the laboratories of R & C Lab Altavilla Vicentina, and it allowed both to identify the microorganisms of attack, it is the best mixture of biocides principles that could lead to their elimination. In collaboration with the Leonardo Borgioli of Technical Office of CTS has been developed a method of intervention for the moai called Hature Huke, based on a series of treatments that depart from the application of a broad-spectrum biocide, identified as Biotin T, followed by mechanical removal using brushing and scalpels of microorganisms now disabled.

Lorenzo Casamenti proceeds to the mechanical removal of lichens after treatment with Biotin T.

At the end of the cleanup phase you will proceed with the application of the estimated biocide consolidation effect, which is now known as Bio Estel New, it is based on the ethyl silicate and a cocktail of molecules with a wide spectrum of action. After an interval of 1 month for complete consolidating reaction, it is always necessary for consolidating based on ethyl silicate that will be applied as a water-repellent preservative which reduces the absorption of water at once; the artifact will again exposed to atmospheric agents. This protection has been identified through a series of comparison tests with other products. It is the Fluoline HY, fluoroelastomer-based solvent, which has properties of high water repellency and regrouping surface. The product had been the subject of studies by the CNR-ICVBC that had shown stability in the light and the property to be fully removable in a solvent, even after aging (M. Camaiti, L. Borgioli, L. Rosi; "Photo stability of innovative formulations for artworks restoration" Chemistry and Industry, november 2011). We will keep you updated in future issues of the CTS Bulletin on the progress of these treatments.  

: Lorenzo Casamenti is not a new intervention in remote locations: between the various sites around the world were just those of the murals in the Catholic cathedral in New Delhi and in the church of San Francesco in Dehradun in northern India, and even related to the complex Piazza Italian marble and bronze in Mendoza, Argentina.