Laser Cleaning FAQ

Question 1

What does wattage mean in a laser cleaning system?

Accepted Answer

Wattage — expressed in watts (W) — is the average power output of the laser. In simple terms, higher wattage means the laser delivers more energy per second, which translates directly to faster cleaning speed and the ability to tackle heavier contamination. A 100W system will clean the same rust patch as a 50W system, but in roughly half the time. A 1000W continuous wave system will clear the same area many times faster again. Wattage is the primary specification to consider when matching a system to your throughput requirements.

Question 2

Does higher wattage always mean better results?

Accepted Answer

Not necessarily. Higher wattage means more cleaning power and speed, but it also means more thermal energy is being delivered. For delicate substrates — thin sheet metal, historic stonework, timber — a lower-wattage pulsed system gives you fine control that a high-power continuous wave machine cannot offer. The right wattage depends on your substrate, the contamination you are removing, and how much throughput you need.

Question 3

What wattage do I need for my application?

Accepted Answer

As a general guide: 50W–200W suits light restoration work, mould cleaning, and portable applications where you need to move the unit around. 200W–500W covers most industrial surface preparation tasks. 500W–1000W pulsed handles demanding batch processing where speed matters but substrate protection is still important. 1000W–3000W continuous wave is for heavy-scale industrial removal — thick rust, mill scale, pipeline descaling — where maximum throughput is the priority and substrate thermal sensitivity is not a concern.

Question 4

What is pulse energy, and how does it differ from wattage?

Accepted Answer

Pulse energy — measured in millijoules (mJ) — is the amount of energy delivered in a single laser pulse. Wattage tells you average power; pulse energy tells you how much energy arrives in each individual burst. Two systems can have the same average wattage but very different pulse energies depending on how many pulses they fire per second (the pulse frequency, measured in kHz). A lower frequency with the same average wattage produces higher energy pulses — which means more ablation force per pulse, but fewer pulses per second.

Question 5

Why does pulse energy matter for cleaning?

Accepted Answer

Higher pulse energy means each individual pulse hits harder. This is important for stubborn contamination — thick oxides, tenacious coatings, or materials that need a sharp energy spike rather than sustained heat to be ejected from the surface. Low-energy, high-frequency pulses are gentler and more suited to fine work on sensitive surfaces. Understanding this relationship — peak power, pulse energy, and frequency — allows you to tune the machine precisely for your material.

Question 6

How is peak power different from average power?

Accepted Answer

Average power is the wattage rating — the total energy delivered per second averaged across pulses and gaps. Peak power is the power delivered at the peak of each individual pulse. Because pulsed lasers concentrate energy into very short bursts, peak power can be tens or even hundreds of times the average power. A 100W pulsed system might deliver peak powers of 10,000W or more during each nanosecond-scale pulse — which is why pulsed lasers can ablate contamination so effectively without the sustained heat that would come from a 100W continuous beam.

Question 7

What is the scanning head and how does the lens affect performance?

Accepted Answer

The scanning head (also called the wobble head or scan head) contains a set of galvanometric mirrors and a focusing lens. The mirrors steer the laser beam rapidly across the surface in a programmed pattern — typically a line, rectangle, or circle — and the lens focuses the beam to the correct spot size at the working distance. The lens is one of the most important optical components in the system and directly affects spot size, working distance, and energy density at the surface.

Question 8

What does the focal length of the lens determine?

Accepted Answer

Focal length — commonly 163mm, 254mm, or 330mm — determines the working distance (how far from the surface the head operates) and the focused spot size. A shorter focal length produces a smaller, more concentrated spot with higher energy density — more aggressive and precise, but with a narrower cleaning line width. A longer focal length gives you a larger spot size and wider cleaning pattern with lower energy density — better for covering large areas quickly at the expense of peak ablation force. The choice of focal length is matched to the application: fine detail work uses a short focal length; large-area industrial cleaning uses a longer one.

Question 9

What is scan width and why does it matter?

Accepted Answer

Scan width is the width of the cleaning stripe produced by the scanning head's mirror movement. A wider scan width means more surface is covered per pass, which increases throughput on flat surfaces. However, increasing scan width spreads the same energy over a larger area, reducing energy density. The optimal scan width balances coverage speed against sufficient energy density to ablate the specific contamination you are dealing with.

Question 10

Do I need to clean or replace the lens?

Accepted Answer

The focusing lens sits inside the scanning head and is protected from direct exposure to ablation debris. However, over time — particularly in dusty or heavy-scale environments without adequate fume extraction — contamination can accumulate on optical surfaces and degrade performance. Regular inspection and cleaning of optical surfaces, and ensuring effective fume extraction is in use, will maintain system performance and protect the optics from premature wear.

Question 11

What is the fundamental difference between pulsed and CW laser cleaning?

Accepted Answer

A pulsed laser fires the laser in short, discrete bursts — typically nanoseconds long — with gaps between each pulse. During the pulse, peak power is very high; between pulses, the laser is off and the surface cools slightly. This prevents heat from building up in the substrate and makes pulsed cleaning substrate-safe — ideal for thin metals, alloys, delicate surfaces, and materials where heat could cause distortion or damage. A continuous wave (CW) laser fires a constant, uninterrupted beam. There are no gaps and no cooling periods. This delivers energy to the surface at a sustained rate, which makes it extremely fast at removing heavy contamination but also means significant heat is generated in the substrate. CW cleaning is used where the substrate is robust enough to tolerate the thermal input — structural steel, thick castings, heavy rust scale.

Question 12

Can a pulsed laser do everything a CW laser can?

Accepted Answer

A pulsed laser can remove most of the same contamination types as a CW laser, but more slowly on heavy material. The advantage of pulsed is its substrate safety — it can tackle applications where CW would cause thermal damage. For heavy industrial scale-removal tasks where throughput is critical and the substrate can handle heat, CW is the better tool. For anything where substrate integrity matters, pulsed is the correct choice.

Question 13

Which is safer to operate — pulsed or CW?

Accepted Answer

Both pulsed and CW fibre laser cleaning systems are Class 4 lasers and require appropriate operator protection: laser safety goggles rated for the relevant wavelength (typically 1064nm for fibre lasers), a controlled work area, and ideally an enclosure or safety interlock. From a substrate safety perspective, pulsed systems carry less risk of inadvertently damaging the material being cleaned. From an operator safety standpoint, both require the same standard of protection.

Question 14

What is modulated CW, and how does it compare to true pulsed?

Accepted Answer

Some continuous wave systems offer modulation — essentially switching the CW beam on and off at a set frequency to simulate pulse-like behaviour. Modulated CW is not the same as a true pulsed laser. True pulsed lasers achieve very short pulse durations (nanoseconds) with extremely high peak powers that modulated CW cannot replicate. If substrate sensitivity is a genuine requirement, a true pulsed source — such as those from JPT or Raycus — is the correct specification.

Question 15

What laser sources do ApexLase systems use?

Accepted Answer

All ApexLase systems are powered by Tier 1 fibre laser sources from Raycus, JPT, or NLight — three of the most established and widely trusted names in industrial fibre laser manufacturing. These sources are specified for their proven reliability, consistent beam quality, and long service life. ApexLase does not use unbranded or grey-market laser modules.

Question 16

What laser safety class are fibre laser cleaning systems?

Accepted Answer

All fibre laser cleaning systems — pulsed or CW — are Class 4 lasers under the BS EN 60825-1 standard. Class 4 is the highest hazard category. Direct exposure to the beam or significant diffuse reflections can cause immediate and permanent eye injury and serious skin burns. Class 4 lasers require a controlled work area, appropriate signage, safety interlocks where practical, and correctly rated personal protective equipment for all operators and bystanders.

Question 17

What personal protective equipment (PPE) is required?

Accepted Answer

As a minimum, operators and anyone in the beam hazard zone must wear laser safety goggles rated for the relevant wavelength — for fibre lasers, this is typically 1064nm. The OD (optical density) rating required depends on the power level and exposure time; this should be calculated for each specific system. Goggles rated for 1064nm at OD6 or higher are common for industrial fibre laser use. Standard welding goggles or tinted glasses do not provide adequate protection. In addition, appropriate clothing to protect against skin exposure and a fume extraction system to capture ablated particles are required.

Question 18

Do I need a laser safety officer?

Accepted Answer

UK Health and Safety legislation does not specifically mandate a Laser Safety Officer (LSO) by job title, but it does require that the risks from laser radiation are properly assessed and controlled under the Control of Artificial Optical Radiation at Work Regulations 2010. For Class 4 laser systems, a formal risk assessment is required, and a competent person should oversee the implementation of control measures. Many employers designate a Laser Safety Officer to fulfil this role. We recommend consulting your health and safety adviser when implementing a laser cleaning system in a workplace.

Question 19

Can I use a laser cleaner outdoors?

Accepted Answer

Laser cleaning systems can be used in outdoor environments, but additional precautions are required to manage the extended beam hazard zone. Without the natural boundaries provided by walls and enclosures, the area in which unprotected individuals could be exposed to reflected or scattered radiation becomes much larger. A site-specific risk assessment, adequate cordoning, and appropriate signage are necessary. Portable pulsed systems intended for outdoor restoration work should always be operated with a clearly defined and controlled hazard perimeter.

Question 20

What materials can be laser cleaned?

Accepted Answer

Laser cleaning is effective on a wide range of metallic and non-metallic substrates. Common metals include mild steel, stainless steel, aluminium, cast iron, copper, brass, and titanium. Non-metallic surfaces that can be laser cleaned include stone (limestone, granite, sandstone, brick), concrete, certain composites, and timber. The key principle is differential absorption — the laser parameters are tuned so that the contamination layer absorbs the energy and is ablated, while the substrate absorbs less and is preserved. Not every contamination/substrate combination is suitable; we recommend discussing your specific materials before specifying a system.

Question 21

What contaminants can be removed?

Accepted Answer

Laser cleaning can remove a broad range of surface contaminants including rust, mill scale, and other iron oxides; paint, primer, powder coat, and epoxy coatings; anodising and oxide layers on non-ferrous metals; organic deposits including mold, algae, and biological growth; soot, carbon, and fire residue; grease and hydrocarbon contamination; graffiti; and rubber or gasket residue. The effectiveness depends on the absorption characteristics of both the contaminant and the substrate at the laser's wavelength.

Question 22

Will laser cleaning damage the base material?

Accepted Answer

A correctly specified and configured pulsed laser cleaning system will not damage the base material. The process relies on the different absorption coefficients of the contamination layer and the substrate — the contamination absorbs the laser energy and is ejected, while the substrate reflects or conducts away the energy before it can cause damage. However, incorrect settings — particularly excessive power, too slow a scan speed, or too small a spot size — can cause localised heating or surface modification. This is why proper specification and operator training matter. Continuous wave systems deliver sustained energy and are not appropriate for thermally sensitive substrates.

Question 23

Can laser cleaning be used on aluminium?

Accepted Answer

Yes, but aluminium requires careful parameter selection. Aluminium has a higher reflectivity at 1064nm than steel, which means more of the laser energy is reflected rather than absorbed by the contamination layer. This can reduce cleaning efficiency and increase the risk of surface modification if parameters are not correctly set. For anodise removal, oxide layer treatment, and pre-bond surface preparation on aluminium, pulsed systems with appropriate parameters are used successfully throughout the aerospace and automotive industries.

Question 24

How difficult is a laser cleaning system to set up?

Accepted Answer

Modern fibre laser cleaning systems are designed for practical industrial use. They arrive pre-configured and require connection to a suitable power supply, connection of the cooling circuit (for water-cooled systems), and attachment of the scanning head. Initial commissioning typically involves confirming the beam alignment and setting baseline parameters for the intended application. Compact pulsed systems are essentially plug-and-play once the safety requirements are met; larger CW systems may require more involved installation. We provide setup guidance with every system.

Question 25

What power supply do I need?

Accepted Answer

Most systems from 50W to 300W operate from a standard single-phase 230V supply and draw between 1kW and 3kW. Higher-power systems — particularly CW units from 1000W upward — typically require a three-phase supply. Exact supply requirements are specified for each individual system. If you have any uncertainty about your site's supply capability, this should be verified before purchase.

Question 26

What does a water cooling system involve?

Accepted Answer

Water-cooled laser cleaning systems use a closed-loop water chiller to maintain the laser module and scanning head within their operating temperature range. The chiller connects to the laser cabinet via hose connections and circulates water continuously during operation. Most chillers require only a standard 13A or 16A power supply and a fill of distilled or deionised water. They are compact, self-contained units that sit alongside the laser cabinet. Air-cooled systems on lower-power models require no water connection but have lower duty cycle ratings.

Question 27

How much training does an operator need?

Accepted Answer

An operator needs to understand the laser safety requirements for Class 4 systems, how to correctly don and use their PPE, how to set the basic parameters (power, frequency, scan width, and scan speed) for their specific application, and how to operate the fume extraction system. Practical experience on a representative sample of your actual material is valuable before beginning production work. We can advise on appropriate training resources. Most operators are productive within a day of starting on their specific application.

Question 28

How long do fibre laser cleaning systems last?

Accepted Answer

The fibre laser module itself — the core light-generating component — is rated for tens of thousands of hours of operation when used within its specified parameters. Raycus, JPT, and NLight modules are all rated at 100,000 hours or more under controlled conditions. In practice, the service life of a system depends heavily on how it is used, whether appropriate fume extraction is maintained to prevent contamination of optical components, and whether the cooling system is properly maintained. With appropriate care, a well-specified system should provide many years of productive use.

Question 29

What routine maintenance does a laser cleaning system need?

Accepted Answer

Routine maintenance tasks include: regular inspection and cleaning of the protective window on the scanning head (a sacrificial optical element that protects the internal optics from ablation debris); checking and topping up the water cooling circuit with distilled water; periodic inspection of hose connections and cable routing; and cleaning or replacing the fume extractor filter according to the extractor manufacturer's schedule. The laser module itself is sealed and requires no routine maintenance beyond keeping the cooling circuit clean.

Question 30

What is the protective window and how often does it need replacing?

Accepted Answer

The protective window (also called the cover slide or protective glass) is a sacrificial optical component mounted at the output aperture of the scanning head. Its purpose is to intercept ablated particles and debris before they can reach and contaminate the more expensive internal optics. In normal operation with adequate fume extraction, a protective window may last for months before requiring replacement. In heavy-duty operation without effective extraction, it may need replacement more frequently. Replacement protective windows are low-cost consumable items.

Question 31

What should I do if cleaning performance degrades over time?

Accepted Answer

Gradual degradation of cleaning performance is most commonly caused by contamination of the protective window or other optical surfaces, a reduction in cooling effectiveness (scale buildup in the water circuit), or — less commonly — a drift in laser parameters. The first step is always to inspect and clean or replace the protective window. If performance does not recover, check the cooling circuit and ensure the laser module is operating within its specified temperature range. If the issue persists, contact us for technical support.

Question 32

Where are ApexLase systems supplied from?

Accepted Answer

ApexLase is a UK-based brand established specifically to serve customers in the UK and beyond who need a reliable, knowledgeable local point of contact for laser cleaning systems. We source from established global manufacturers but provide UK-based support, specification guidance, and after-sales assistance.

Question 33

Do you provide demonstrations or trials?

Accepted Answer

We are happy to discuss demonstration options for customers with suitable applications. Get in touch via the contact form and describe your substrate and contamination type — we can advise on the best approach.

Question 34

What fume extraction do I need?

Accepted Answer

Any laser cleaning operation produces ablated particles and fumes. A suitable fume extraction unit with HEPA filtration is required for all indoor operation. The extraction specification depends on the contamination type — lead paint, for example, requires higher-grade filtration than rust removal. We can advise on appropriate extraction specifications for your application.

Question 35

Do you ship across the whole of the UK?

Accepted Answer

Yes. ApexLase supplies systems across England, Scotland, Wales, and Northern Ireland. We can also discuss international supply — get in touch with your location and requirements.

Question 36

What warranty do ApexLase systems come with?

Accepted Answer

Warranty terms are provided with each system at the point of sale and vary by model and specification. All systems are supplied with manufacturer's warranty on the laser module and we provide after-sales support from the UK. Contact us for specific warranty information on the model you are considering.

Understanding Wattage

Pulse Energy (mJ Output)

Lens Type and Size

Pulsed vs. Continuous Wave (CW)

Safety & Laser Classification

Materials & Substrates

Installation & Operation

Maintenance & Service

Buying and Support

Still have a question?