1. Characterization of Laser Cleaning of Artworks

Jan Marczak, Andrzej Koss, Piotr Targowski, Michalina Góra, Marek Strzelec, Antoni Sarzyński, Wojciech Skrzeczanowski, Roman Ostrowski  and Antoni Rycyk

Sensors 2008, 8, 6507-6548; DOI: 10.3390/s8106507

 

Abstract: The main tasks of conservators of artworks and monuments are the estimation and analysis of damages (present condition), object conservation (cleaning process), and the protection of an object against further degradation. One of the physical methods that is becoming more and more popular for dirt removal is the laser cleaning method. This method is non-contact, selective, local, controlled, self-limiting, gives immediate feedback and preserves even the gentlest of relief - the trace of a paintbrush. Paper presents application of different, selected physical sensing methods to characterize condition of works of art as well as laser cleaning process itself. It includes, tested in our laboratories, optical surface measurements (e.g. colorimetry, scatterometry, interferometry), infrared thermography, optical coherent tomography and acoustic measurements for “on-line” evaluation of cleaning progress. Results of laser spectrometry analyses (LIBS, Raman) will illustrate identification and dating of objects superficial layers.

2. Comparative Laser Spectroscopy Diagnostics for Ancient Metallic Artefacts Exposed to Environmental Pollution

Łukasz Ciupiński, Elżbieta Fortuna-Zaleśna, Halina Garbacz, Andrzej Koss, Krzysztof J. Kurzydłowski, Jan Marczak, Janusz Mróz, Tomasz Onyszczuk, Antoni Rycyk, Antoni Sarzyński, Wojciech Skrzeczanowski, Marek Strzelec, Anna Zatorska and Grażyna Z. Żukowska

Sensors 2010, 10, 4926-4949; doi:10.3390/s100504926

Abstract: Metal artworks are subjected to corrosion and oxidation processes due to reactive agents present in the air, water and in the ground that these objects have been in contact with for hundreds of years. This is the case for archaeological metals that are recovered from excavation sites, as well as artefacts exposed to polluted air. Stabilization of the conservation state of these objects needs precise diagnostics of the accrued surface layers and identification of original, historical materials before further protective treatments, including safe laser cleaning of unwanted layers. This paper presents analyses of the chemical composition and stratigraphy of corrosion products with the use of laser induced breakdown spectroscopy (LIBS) and Raman spectroscopy. The discussion of the results is supported by material studies (SEM-EDS, XRF, ion-analyses). The tests were performed on several samples taken from original objects, including copper roofing from Wilanów Palace in Warsaw and Karol Poznański Palace in Łódź, bronze decorative figures from the Wilanów Palace gardens, and four archaeological examples of old jewellery (different copper alloys). Work has been performed as a part of the MATLAS project in the frames of EEA and Norway Grants (www.matlas.eu) and the results enable the comparison of the methodology and to elaborate the joint diagnostic procedures of the three project partner independent laboratories.

3. Set of advanced laser cleaning heads and systems

Jan Marczak, Roman Ostrowski, Antoni Rycyk and Marek Strzelec

Abstract: Paper presents three developments of laser systems aimed at more safe and efficient cleaning of paper and parchment, paintings and metal artworks. Short introduction and scope of our work are included in the first paragraph. In the following sections are presented in details:

- picosecond, diode pumped Nd:YAG laser system with computer controlled manipulation table and proposed “online”cleaning diagnostic systems for cleaning of paper, parchment and paintings,

- ReNOVALasErb laser cleaning system (2.94 μm) with narrowed width of output pulses for cleaning of paintings,

- generator-amplifier Nd:YAG laser configuration aimed at temporal and amplitude shaping of output Q-switched laser pulses for cleaning of metal artworks.