CLEANING WITH LIGHT HOW LASER TECHNOLOGY IS TRANSFORMING STONE CONSERVATION
Laser cleaning is one of the safest and most precise ways to restore stone surfaces because it removes dirt, crust and pollution without damaging the underlying material and the techniques are fast replacing old fashioned methods where suitable and appropriate.
Unlike sandblasting or chemical treatments, laser cleaning doesn’ t abrade or chemically weaken the stone. It targets only the contaminants, leaving carvings, patina, and fine details intact. It does so by very selective treatment. Dirt and soot, absorb laser energy more readily than stone. This means the contaminants vaporize while the stone remains unaffected, thanks to differences in ablation thresholds.
No harsh chemicals or large amounts of water are required. Byproducts are mostly gases or fine particulates, which can be safely extracted with filters. And of course, using only electricity it is a far cleaner alternative to other methods of cleaning.
Laser parameters( energy, pulse duration, scanning speed) can be finely tuned for each stone type and contaminant. This ensures uniform cleaning without overexposure. We always provide test patches and will start with a set of readings which achieve almost nothing and increase incrementally until we reach a good rate of work and satisfactory finish.
Here we have some examples. The first is an entrance to a deconsecrated church being developed into apartments. An award-winning development in London. We were able to achieve these results and still allow the building to be safely used.
The second is a startling image, shown part way through cleaning. The subject is a statue at Rheims cathedral where harmful crust is removed with no degradation of the original stone and retaining patina relevant to the age of the statue.
Here a much more modest listed building in Shropshire which had suffered airborne pollutants from a long-closed flax mill directly up wind of the house. Here again, masonry has been sympathetically cleaned without over cleaning the stone such that looks new.
Finally an historic door, cleaned of heavy discolouration but retaining patina from 100s of years. Though we would have to remove the awful crosshead screw you can see.
www. uklasercleaning. com
16- REFURB & RESTORE