Lasers for the Cleaning of Statuary: Initial Results and Potentialities

Cleaning is one of the most difficult operations encountered in the restoration of statuary. The fact that known cleaning methods are not entirely satisfactory has stimulated continuing research into new methods and processes. A novel method is proposed for cleaning superficial black scabs or patinas from works of art in marble or other stone by means of laser radiation. Surface cleaning results with a ruby laser are reported and compared with conventional techniques. Preliminary analyses of the laser process are quite favorable and indicate improved selectivity and graduation, self-limiting encrustation removal, and remarkably rapid surface coverage. Finally, the results of cleaning tests with various laser types are presented and discussed, and possible future developments and pratical applications of this new method of cleaning statuary are presented.