EFFECTS OF COMMERCIAL NANO-LIME PRODUCTS AS A CONSOLIDATION METHOD FOR WALL PAINTINGS An experimental case study

Abstract: Some of the main deterioration problems concerning wall paintings is structural degradation of the wall painting and the flaking of the painted layer. Consolidation, both in the form of reinforcement of the rendering of the wall painting and the re-adherence of a flaking paint layer to the underlying substrate, have thus been an important part of conservation efforts concerning wall paintings. Since the turn of the millenia dispersions of nanoparticles of calcium hydroxide, sometimes referred to as nano-lime, have been developed as a consolidation method for wall paintings. Research studies investigating the effects of nano-lime as a consolidation method for wall paintings are limited to wall paintings executed in the fresco technique. Current research is also limited to investigating nano-lime used in environments with generally high levels of relative humidity. In this thesis paper the effects of commercial nano-lime products Nanorestore® and Nanorestore Plus®, used on wall paintings in the secco fresco technique in climatic conditions with relatively low levels of relative humidity are investigated. The results of a literary study and an experimental study indicate a significant influence of both the environmental conditions and the constituents of the wall painting rendering in regards to the outcome of the consolidation treatment. The results also highlight the application method as a decisive factor and implies that adjustments in application technique are necessary depending on environmental conditions and the constituents of the rendering of the wall painting. The most important conclusion of this thesis paper is the necessity of further research investigating the effects of nano-lime products in different climates and on different substrates.