Restoration of buildings by means of laser cleaning

Laser cleaning of painted plaster surfaces at  St. Martin in Meerane
© Fraunhofer IWS Dresden
Laser cleaning of painted plaster surfaces at St. Martin in Meerane
Funktionsprinzip des Laserabtragprozesses
© Fraunhofer IWS Dresden
Funktionsprinzip des Laserabtragprozesses
Laser cleaning process at brown paintings of hair and robe
© Fraunhofer IWS Dresden
Laser cleaning process at brown paintings of hair and robe

Non-contact layer ablation is a quite new field of laser applications. A mobile laser unit was tested for suitability at the mural “Einzug in Jerusalem” in the Church of Meerane. The task was to remove contaminants from painted plaster surfaces through a laser cleaning process. The laser`s ability to analyze different pigmentations had to be proved. Of special interest here were the cleaning results on painted plaster surfaces, the laser`s suitability for different pigmentations and the optical effect on the cleaned surfaces (e.g. fading).


Results

The cleaning by manually laser multi scanning of  picture elements – hair and robe with brownish shades – enabled an homogeneous removal without any color changes. The mural`s colors had strongly darkened due to contamination. For the very first time, the laser`s excellent ability could be demonstrated with the damage-free cleaning of the mural`s plaster paintings.