Evaluation of Cleaning and Desalination Techniques for the Conservation of Low-Fired Terracotta Artifacts: A Case Study from Hund Museum, Pakistan

Abstract

Terracotta artefacts are an important part of the archaeological heritage of Pakistan but low-fired terracotta objects are especially vulnerable to deterioration by the environment and by chemical agents because of their porous structure and their limited mechanical strength. This study is an evaluation of cleaning and desalination methods used on twenty-three low-fired terracotta artefacts from the Hund Museum, Swabi, Pakistan. A systematic approach to conservation was adopted, which included condition assessment, photographic documentation, mechanical cleaning, localized wet cleaning using distilled water, selective chemical treatment using diluted hydrochloric acid and repeated cycle desalination for removing soluble salts. The artefacts showed several phenomena of deterioration such as mud accretions, lime incrustations, salt efflorescence, carbon staining, micro-cracking and surface discolouration. Comparative evaluation of the treatment outcomes suggests treating salt affected objects by controlled distilled water immersion was the most effective and least invasive method for stabilizing samples. Mechanical cleaning was found to be appropriate as a major intervention procedure due to the greater degree of control and chemical hazard and the chemical cleaning procedure required careful application because of surface alteration. The study emphasizes compliance with conservation ethics such as minimum intervention, reversible and preservation of patina and evidential use. The results offer a viable and replicable framework for conservation at regional museums with limited technical facilities and add to sustainable heritage management practices for terracotta collections in Pakistan.

Keywords: Terracotta conservation; Desalination; Mechanical cleaning; Archaeological artifacts; Salt deterioration; Museum preservation