Kolloidale Kieselsäure für das Festigen von Naturstein / Colloidal Silica in Stone Conservation

Gypstop, a new product based on silica colloid, has been developed by Eka Chemicals Company in Sweden. It is used in the restoration and conservation of cultural heritagestone monuments. These deteriorate due to the combined effect of gases and salts which may have a synergystic effect. This paper describes the principle of desalination and subsequent consolidation of porous stone and the procedure of using Gypstop. Some of the deteriorated limestone blocks have been treated with the Gypstop in Egypt. It has shown that the Gypstop protects the stone from further weathering. Restoration and conservation of different stone monuments have been carried out. The periodical evaluation of the field treatment has confirmed that the Gypstop has unique characterstic of desalination and subsequent consolidation of the stone monuments. It thus strengthens them and significantly improves their durability.