cleaning art objects by laser
DESCRIPTION
By Sandra SantosTRANSCRIPT
OPTOELECTRÓNICA CML-DMC-DPC-DPC
Sandra Santos
CLEANING ART OBJECTS BY LASER
English Class
OPTOELECTRÓNICA CML-DMC-DPC-DPC
Laser cleaning
Why laser?
How do lasers work?
Some artwork aplications
TOPICS
OPTOELECTRÓNICA CML-DMC-DPC-DPC
STANDARD SYSTEMS
OPTOELECTRÓNICA CML-DMC-DPC-DPC
STANDARD SYSTEMS
Source: “ARTWORK CONSERVATION BY LASER”http://alpha1.infim.ro/cost/
OPTOELECTRÓNICA CML-DMC-DPC-DPC
STANDARD SYSTEMS
a)
b)
c)
d)
e)
Fig. 1: Lynton Laser Nd:YAG - L1a) articulated arm; b) worktable; c) exhausting system; d) laser control panel; e) command and safety labels.
OPTOELECTRÓNICA CML-DMC-DPC-DPC
Reflectingsurface
HOW DO LASERS WORK?
Basic Process: selective vaporization of black crusts(Source : “Laser Cleaning in Conservation”, Martin Cooper)
OPTOELECTRÓNICA CML-DMC-DPC-DPC
Monument to the Memory of the late Lord Nelson – de 1813, Liverpool
Sculpture group in stone and bronze, located in Exchange Flags Square,
Liverpool, designed by Matthew Cotes Wyatt and scalped by Sir Richard
Westmacott, composed by a granite basement and a marble Westmorland. The sculptural work in made in bronze.
Height of bronze group: 4,3 m. Figures 2,1 m each.
Description: Around the drum-shaped pedestal surmounting the granite basement, four shacked prisoners in poses of anguish resignation are seated on blocks positioned at the cardinal points: they represent Nelson’s four great victories at Cape St. Vincent, the Nile, Copenhagen, and Trafalgar. Between the prisoners set into the drum are four bronze bas-reliefs depicting various naval actions in which Nelson engaged. Encircling the drum bellow the cornice are swags of laurel, four longer ones above the relieves and four shorter above the prisoners. The swags are slung from behind lion’s heads located at the top corners of the pilasters framing the prisoners. Surmounting all is the Apotheosis group.
EXPERIMENTAL CLEANING OF METALLIC MATERIALS
OPTOELECTRÓNICA CML-DMC-DPC-DPC
EXPERIMENTAL CLEANING OF METALLIC MATERIALS
Prisoners
Corrosion. Rust. Soiling. Concretions.
OPTOELECTRÓNICA CML-DMC-DPC-DPC
Before the leg cleaning
During the cleaning work
EXPERIMENTAL CLEANING OF METALLIC MATERIALS
Prisoners
OPTOELECTRÓNICA CML-DMC-DPC-DPC
Prisoners
Distance SPOT
Diameter AreaEnergy Aplied
Fluence
(mm) (mm) (cm2) E/P (mJ) (J/cm2)
120 5,2 0,21 358-371 1,7
EXPERIMENTAL CLEANING OF METALLIC MATERIALS
OPTOELECTRÓNICA CML-DMC-DPC-DPC
Letters belonging to the inscription
EXPERIMENTAL CLEANING OF METALLIC MATERIALS
OPTOELECTRÓNICA CML-DMC-DPC-DPC
ANALYSIS OF RESULTS TO THE MICROSCOPE
Laser cleaning
E/P = 125mJ Fi = 10 Hz
F= 0,6 J/cm2
Over cleaned surfaceDamaged surface
Before irradiationCorroded surface
salts accumulation
OPTOELECTRÓNICA CML-DMC-DPC-DPC
Before irradiationCorroded surface
salts accumulation
Laser cleaning
E/P = 81 mJ Fi = 10 Hz
F= 0,2 J/cm2
Microphotograph of brass surface before the irradiation. Image with Magnification 16 x. Width of original image 21 cm.
EXPERIMENTAL CLEANING OF METALLIC MATERIALS
OPTOELECTRÓNICA CML-DMC-DPC-DPC
E/P = 154 mJ, Fi = 10 Hz F= 0,4 J/cm2
Corrosion removal whithout causing damage on the surface - acceptable cleaning level
E/P = 125mJ, Fi = 10 Hz F = 0,3J/cm2, wet surface
ANALYSIS OF RESULTS TO THE MICROSCOPE
OPTOELECTRÓNICA CML-DMC-DPC-DPC
FINAL RESULTS
OPTOELECTRÓNICA CML-DMC-DPC-DPC
FINAL RESULTS
OPTOELECTRÓNICA CML-DMC-DPC-DPC