Photons in.
Rust out.
The first time you watch a laser strip rust off a steel beam it looks like a magic trick: a thin green line drawn across the surface, and the brown is simply gone. There is no trick. What you are seeing is a controlled, repeatable physical process. Here is what is actually happening.
A focused beam, not a flame.
The line you see is the focused laser sweeping across the surface. It is not heat in the way a torch is heat: the energy is delivered in extremely short bursts, each one targeting only the top layer of contaminant.
The rust is becoming a gas.
That faint cloud is oxide leaving the surface as vapour and fine dust. It is captured by an extractor sitting just above the work area - none of it returns to the substrate.
Bare metal, as the surface was cast.
Behind the beam, the original surface profile is revealed. No abrasive has touched it, no chemistry has wetted it. Tolerances, threads and stamps stay exactly as the foundry left them.
Three things everyone asks on a first call
Different materials have very different appetites for light at our working wavelength. Rust, oxide and most paints absorb it greedily - they go to vapour at relatively modest energy. Clean steel reflects most of the same beam and conducts heat away from the spot before damage can occur.
There is, in other words, a comfortable window in which we can sit: too hot for the contaminant to survive, too cold to touch the metal underneath. Finding the centre of that window for your particular surface is the job we do in the first ten minutes on site.
It leaves the surface as a mixture of hot gas and microscopic particulate. Sitting a few centimetres above the work zone is a HEPA-class extractor: it draws the plume in, cools it, and traps the solids in a sealed filter cartridge.
The cartridges are weighed, logged and disposed of through Switzerland's licensed special-waste channels. There is no rinse water, no chemical run-off, no sand pile to sweep up.
For light rust or weld discolouration on accessible flat steel, expect roughly two to four square metres per hour with a single 300 W head. Heavy multi-layer paint, or anything inside a confined geometry, comes in slower - sometimes half a square metre per hour.
Headline numbers are useful for budgeting, but the only honest figure for your job comes out of our witness test: a few minutes of cleaning on a representative patch, timed, photographed, and used to quote the rest of the surface.
A four-stage cycle, twenty thousand times a second.
- 01
The pulse leaves the head.
A burst of light, about a hundred nanoseconds long, exits the optical fibre and is focused to a spot roughly half a millimetre wide.
- 02
The contaminant absorbs it.
Rust, paint, oxide or carbon residue swallow the energy almost completely. The clean steel beneath reflects most of what would have reached it.
- 03
The layer leaves as vapour.
That micrometre-thin slice of contaminant turns into hot gas in the time it takes for sound to cross a single grain of sand. The extractor catches it on the way up.
- 04
The spot cools - and the next pulse arrives.
Fifty microseconds of nothing. The substrate sheds its tiny heat spike into the surrounding bulk. Then the cycle repeats, a step further along.
What we actually bring to your site.
The source is a pulsed fibre laser - a length of doped glass fibre acting as the amplifier. Fibre lasers are the workhorses of industrial cleaning because they are robust, air-cooled, and their beam stays optically perfect for tens of thousands of hours of use.
The head is what the operator holds. Inside it: a small mirror that wobbles at high speed, sweeping the focused beam across a line a few centimetres wide. That wobble is the green stripe you see in the animation. Outside it: a safety trigger, a guide light, and a stand-off nose that keeps the focal distance constant.
Power, frequency and scan pattern are programmable. We keep a library of recipes for the materials we see most often - Corten steel, galvanised sheet, sandstone façades, beech beams - and adapt them on site to whatever the surface actually presents.
Field unit · standard configuration
In serviceWhere the laser earns its keep - and where it doesn't.
Most-asked surfaces
~70% of callsWhere laser cleaning is almost always the right tool. Robust process, predictable speed, well-rehearsed recipes.
- Oxidised mild and Corten steelstructural beams, agricultural machinery
- Painted and powder-coated metalstripping for re-coating, weld prep
- Cast iron - heat exchangers, brake partstypical for industrial overhauls
- Stainless after weldingremoval of heat-tint and pickling residue
- Aluminium oxide and anodisingaerospace and architectural panels
Also handled, with care
~25% of callsMore sensitive substrates. Slower, lower-power recipes; we always pre-test in an off-camera area before committing.
- Limestone, sandstone, granitefaçades, statuary, fountain basins
- Hardwood timberfire damage, soot, biological growth
- Bronze and brass with patinaconservation work - we preserve the patina you want
- Painted concrete and brickgraffiti removal without acid washing
- Moulds and machined toolingrelease residue, slag, between-cycle deposits
Where we say no
~5% of callsSubstrates that absorb at our wavelength, or that the laser simply doesn't outperform an established method on.
- Most plastics and elastomersthey absorb the beam - damage risk too high
- Thin clear-coated woodbetter suited to manual or chemical methods
- Glass with surface coatingsdelamination risk we cannot reliably control
- Live circuit boards and electronicswe will not work near energised assemblies
- Anything thinner than 0.5 mm sheetthermal load is small but real - we discuss it case by case
The boring half of the job we take seriously.
On site
Everyone within ten metres is protected, by default.
The working zone is delimited with portable laser-grade screens or temporary curtains. Wavelength-rated eye protection is on every operator and visitor, including the customer. Reflective objects, glossy paint and polished steel inside the zone are covered or repositioned before the first pulse.
- Operators certified to Swiss occupational-safety standards (SUVA / OSHA)
- A laser-safety officer assigned to every job site
- Pre-work briefing for client staff on access to the controlled area
What comes out
Spent contaminant is logged and disposed of properly.
The extractor's HEPA cartridge collects the entire plume - paint flakes, oxide dust, organic residues. Cartridges are weighed at the end of each job. When the contaminant is classified as hazardous (lead-based paints, chromate primers, asbestos-adjacent matter), the load is routed through Switzerland's licensed special-waste collectors with full chain-of-custody paperwork.
- Zero rinse water, zero abrasive media to recover
- Cartridge mass and waste class included in the closing report
- Heritage projects receive the dust separately for archival, if requested
Bring us a problem surface - we'll show you what comes off.
An on-site demo runs about forty minutes: ten minutes of setup, twenty minutes of cleaning a section you nominate, ten minutes of looking at the result together. There is no charge for qualified projects anywhere in Switzerland.