Laser cleaning is applied to clean historical monuments, buildings, and stonework to restore their original appearance.
Laser cleaning is a gift of the Physics community to help preserve historical structures. Air pollution and particularly sulfuric acid aerosols interact with calcium carbonate statues to form a layer of gypsum which is made of calcium sulfate and water. Laser cleaning can be used to remove film deposits and contaminants such as sulfates and nitrates from marble structures.
Laser ablation is an excellent method to restore antiques due to our ability to fine tune the laser strength providing unmatched results when compared to legacy restoration methods. As a general rule of thumb, anything metallic should be a great application. Given that metals are reflective, the laser tends to only interact with surface contamination as opposed to the substrate when properly tuned. Proper use will negate warping of thin or delicate metals while producing a clean surface that is dry. All contaminates can be captured with fume extraction. Laser is a precise, safer and eco-friendly alternative to traditional methods.
A laser is a unique source of energy, providing an intense, highly directional, pure form of light that is able to deliver energy to a surface in a highly controllable manner. The most commonly used laser cleaning systems in conservation emit very short pulses of infrared light, typically at a wavelength of 1064 nm. Light at this wavelength tends to be absorbed strongly by pollution encrustations and many other types of dirt layers and surface contaminants, whereas the surface of the artwork often reflects this light strongly; to some extent the laser beam is able to differentiate between the dirty and clean surfaces.
The energy absorbed by the dirt layer is almost instantaneously converted into heat; this extremely fast heating effect generates forces sufficiently strong to eject the dirt particles away from the surface. In many cases, the light interacts only weakly with the surface of the artwork and the removal process stops as soon as the clean surface is exposed.
The control offered by laser cleaning enables the conservator to remove unwanted layers without overcleaning the valuable surface of the artwork; patina, fine surface detail, tool markings and important surface coatings can be preserved. Laser cleaning systems provide the conservator with an extremely gentle method of cleaning which can be used to remove dirt from very fragile surfaces; from a badly weathered marble surface in need of consolidation or from the delicate petals of a rose, as seen in the video clip above.
Laser cleaning technology is a remarkable and unique tool for architectural restoration and conservation. Cleaning with laser light has proven to be the most gentle and effective method for restoring the beauty of historic architectural treasures including sculptures, bronze statues, ornate terracotta as well as entire building façades.
Laser cleaning removes harmful and unsightly deposits without chemicals, abrasives, water, dust or residues that can permanently damage historic surfaces. Moreover, laser cleaning is a green process; it produces no secondary waste, no run-off and no dust that can pose risks to people and the planet. Laser cleaning offers conservators an amazing tool to clean and enhance historic surfaces in a way not possible with any other method.
- Gentle cleaning with light
- No abrasion on delicate surfaces
- Non-contact / non-kinetic – only laser light processes the surface
- No chemicals, no consumables, no blast media
- Totally dry cleaning process – no water or liquids that can cause moisture damage & corrosion
- Easy to operate & easy to adjust
- Mobile laser systems with a handheld head can go virtually anywhere
- High reliability with low maintenance
- Minimal operating costs
- Environmentally friendly – Clean & Green
Graffiti is often removed by using steam or chemicals. The disadvantage of these techniques is the fact that they’re not always as effective as they should. With other techniques, like sandblasting, there is a risk of damaging or wearing down the underlying layer. This forms a problem with softer stone types and historical buildings.
Laser cleaning is very suitable for removing graffiti. The laser beams will quickly heat up the paint layer, which then will evaporate. The underlying stone or concrete layer remains cool because of its higher ablation temperature. So the laser beams will have no effect on the underlying stone or plaster layer. Even on wood or glass, paint can be removed!
When using sufficiently powerful laser sources, the removal of graffiti goes very fast. Depending on the age, the color and the thickness of the paint layer, we are able to clean a square meter full of paint in half an hour.
Thanks to its quick cleaning, laser cleaning is comparable in price to the other techniques, but has so much better results.
Laser technology can gently clean and remove soil from sandstone, marble, granite, terracotta as well as concrete without causing physical damage or harm architectural surfaces. Laser light can precisely clean colored and pigmented surfaces to remove centuries of soot, unsightly soil to restore the original beauty.
Very precise adjustment of the laser system’s power, from 0-100% and intensity through interchangeable laser optics, provide a unique and innovative tool for restoration unlike any other available.