| Abstrakt: |
The goal of a masonry cleaning programme is typically to remove surface contaminants without damaging the substrate. Cleaning techniques are continually being refined in an effort to provide more effective and environmentally sustainable methods with less potential to damage substrates. Specific goals of new technologies address the preservation of patina while systematically removing various types of soiling deposits, staining, organic growth, and coatings. This paper provides a summary overview of cleaning technologies and techniques currently used in conservation practice as applicable to masonry. For systems presently used for cleaning masonry, the paper focuses on appropriateness for different substrates and conditions based on laboratory studies, case study examples, and published literature. Systems addressed include water and steam cleaning methods; wet and dry abrasive systems; laser-based cleaning systems; chemical cleaners; coating removal systems; and biocides. The paper examines the conservation precepts and standards that provide a framework for cleaning projects and provides a proposed methodology for masonry cleaning. Issues addressed include the establishment of cleaning criteria, understanding the nature of the substrate and soiling, evaluating advantages and disadvantages of cleaning systems, developing project-specific documents, the importance of in situ trial samples, and providing quality control. [ABSTRACT FROM AUTHOR] |
