To truly master laser cleaning parameters, one must first grasp a key concept, the cut-off frequency, which can also be called the power-derating frequency point. It is arguably the most easily overlooked yet most decisive parameter in the entire laser cleaning parameter system. Before elaborating, let me first introduce a core formula: average power = single-pulse energy × repetition rate, i.e., P(W) = Ep(J) × F(Hz). In our equipment, the frequency F is generally expressed in kHz, and since 1J equals 1000mJ, we can directly use mJ × kHz to convert to the actual maximum power. For example, a 300W, 5mJ unit has a cut-off frequency of 300÷5 = 60kHz, meaning this 300W unit can deliver full power output at a frequency of 60kHz.

With this in mind, the essence of the cut-off frequency becomes clear. If the frequency is set above the cut-off frequency, say 80kHz, then, working back through the formula, the single-pulse energy becomes 300÷80 = 3.75mJ. Because the laser's total power is only 300W, the system automatically reduces the single-pulse energy to satisfy the higher frequency setting. In other words, when the frequency is set above the cut-off frequency, the system lowers the single-pulse energy; when the frequency is below the cut-off frequency, even if you set the power to its rated maximum, the actual output power remains insufficient. This is precisely the definition of the cut-off frequency. This naturally raises a question: since the cut-off frequency is so critical, does the pulse-width setting become a mere formality? Can you simply set the cut-off frequency and rely on pulse width to handle every condition? The answer is no. The 2mJ, 5mJ and similar parameters printed on the nameplate are all the equipment's maximum single-pulse energy. Pulse width and frequency can be adjusted independently, but each pulse-width setting corresponds to a dedicated cut-off frequency, and the unit typically delivers its maximum single-pulse energy at a pulse width of 500ns; below 500ns, the single-pulse energy decreases while the cut-off frequency rises. Taking the 300W, 5mJ unit as an example: when the pulse width is set to 80ns, its cut-off frequency must be raised to 200kHz to achieve full-power output of 300W, but at this point the single-pulse energy is only 1.5mJ, a reduction of 3.33 times versus the maximum energy. If severe rust is being cleaned under these conditions, the cleaning capability will drop noticeably due to insufficient single-pulse energy. Therefore, the equipment's cut-off frequency table is the lifeline of parameter adjustment.

From this, the key rules of the cut-off frequency can be summarized: the frequency and pulse width together determine energy distribution. Below the cut-off frequency, total energy is insufficient; above it, the single-pulse energy drops. The lower the pulse width, the higher the cut-off frequency and the lower the single-pulse energy; the higher the pulse width, the lower the cut-off frequency and the higher the single-pulse energy, with the maximum usually achieved at 500ns. A reference table of cut-off frequency, pulse width, and single-pulse energy is appended here for your convenience in consulting and adjusting parameters.

How should pulse width be adjusted, and what is its operating principle? Pulse width represents the duration of each individual laser pulse and is the most fundamental underlying parameter in MOPA pulsed laser cleaning. It directly determines the pulse peak power and the heat-affected zone, while also bounding the usable repetition-frequency range of the laser. Under the same single-pulse energy, a shorter pulse width yields higher peak power; energy is released in an extremely short time, and material removal relies primarily on thermal shock and plasma ablation. Because heat has little time to conduct into the substrate, the heat-affected zone is small, making short pulse widths suitable for precision substrates. Conversely, a longer pulse width lowers the peak power and prolongs the laser-material interaction time, allowing heat to diffuse more readily into the substrate; the thermal effect accounts for a larger share, strengthening the ability to strip thick contaminants, yet the risk of substrate discoloration and thermal damage rises correspondingly. Accordingly, thin oxide films, thin paint layers, aluminum parts and thin-walled precision parts should preferentially use short pulse widths (20–150ns), leveraging high peak power for cold ablation while controlling thermal damage; thick rust, thick coatings, heavy oil contamination and heat-resistant substrates such as thick steel plates should instead use long pulse widths (150–500ns), relying on the longer energy-interaction time to achieve thick-layer stripping, while remaining alert to heat accumulation so as to avoid high-temperature discoloration or even deformation of the substrate. In light of the cut-off frequency concept discussed above, after selecting a pulse width one must consult the laser's pulse-width–cut-off-frequency parameter table; the actual repetition frequency must not exceed the cut-off frequency corresponding to the current pulse width. Once the limit is exceeded, the laser triggers power derating, and the set parameters will completely diverge from the actual output.

Summary. The laser cleaning parameter system can be distilled into three main threads. First, the cut-off frequency is the dividing point between frequency and energy: below it, total energy is insufficient; above it, the single-pulse energy drops. Second, pulse width and frequency can be adjusted independently, but each pulse-width setting corresponds to a dedicated cut-off frequency; the maximum single-pulse energy is obtained at the longest pulse width (typically 500ns), and the shorter the pulse width, the lower the energy ceiling. Third, pulse width determines the mode of action and the heat-affected zone. Short pulse widths favor precision, long pulse widths favor thick layers, and when adjusting, one must, within the constraints of the cut-off frequency table, use frequency to balance the actual single-pulse energy.

There is no universally applicable one-size-fits-all parameter set for laser cleaning. Only by thoroughly understanding the operating mechanisms of the cut-off frequency and pulse width, and then calibrating on a case-by-case basis in light of contaminant-layer thickness and substrate sensitivity, can you clean effectively while protecting the substrate. I hope this parameter overview helps you avoid detours and, in every cleaning job, tune out stable, efficient, and reliable operating parameters.

I have a co2 laser and want to cut out a stencil in my laser, then apply it to a glass cup, then sandblast it.

I don’t have a rotary yet.

I’m in Canada. Best product you can recommend that will be co2 laser friendly.

Thank you

Here's a before and after on a job we just finished. It's walnut. First time using a laser to remove the finish. Turned out fantastic!!!

Video: https://youtube.com/shorts/YdMcRSrjmXM?si=wenPi7q3yWgJ9CFk

Bonjour à tous . Je suis en train de lancer mon entreprise de nettoyage et décapage laser (matériel de Classe 4), mais je me heurte à un vrai blocage pour trouver une RC Pro : les assureurs classiques (refus de la MAAF, dossier bloqué chez AXA) n'ont pas la mention « laser » dans leurs nomenclatures d'activité (ils connaissent l'hydrodécapage ou la cryogénie, mais pas le laser) et refusent ou hésitent fortement à ajouter ce terme au contrat. Pour ceux qui travaillent dans ce domaine ou dans le traitement de surface innovant, je serais très reconnaissant de savoir par quelle compagnie ou quel courtier vous êtes passés et sous quel libellé d'activité exacte votre contrat a été rédigé.

This WWII army trailer spent decades collecting rust, paint, and corrosion. Soon its new mission is rolling alongside a restored 1944 Willys Jeep.

In this video, we laser clean the full trailer: body, axle, leaf springs, brake drums, and all the hardware. Watch the laser strip layers of rust and old coating down to clean, sound steel, ready for primer and paint.

Why laser for a restoration like this:
• No abrasive media stuck in seams, welds, and pinholes on 80-year-old steel
• No friction heat that can warp thin vintage sheet metal
• No harsh chemical strippers soaking into old welds and joints
• You can see the condition of the actual metal as it's revealed which is perfect for finding what needs repair vs. what just needed cleaning
• Selective cleaning takes paint off one area without touching adjacent surfaces

We're a mobile laser cleaning service based in New Jersey: rust removal, paint and powder coat stripping, surface prep, and restoration work at our shop, at your location, or ship-to-us.

📞 Want your project done? Contact us for a quote:
📍 Serving New Jersey and the surrounding region

#WWII #MilitaryRestoration #WillysJeep #LaserCleaning #RustRemoval #TrailerRestoration

Just 24 hours after we published our post on cleaning a violin, we were flooded with harsh comments accusing us of destroying a work of art. But those tests had also revealed the limitations of our equipment, so this time we set our sights on a traditional Chinese instrument: the guqin.

Authentic guqins are crafted from paulownia (tong) and catalpa (zi) wood and finished with raw lacquer, a natural resin. We hunted one down on a secondhand marketplace for about $30. Yet when our engineers inspected the finish, they found it was coated not in natural lacquer but in acrylic varnish, a modern synthetic. We later learned that a true high-end guqin finished with natural resin typically commands upward of $1,500.

This instrument posed a very different challenge from the violin because it features a two-layer coating system. The base coat levels the surface. Since the wood carries wormholes, growth rings, and grain, and since guqin playing often involves sliding across the soundboard, this layer is essential for creating a smooth playing surface. The top coat, meanwhile, adds further smoothness and luster, enhancing both the instrument's appearance and its playability.

We used a dedicated wood-cleaning laser machine and ran the process twice for optimal results. The first pass removed the top coat and most of the base coat at 300 W, 150 kHz, 150ns, with an X-direction scan pattern, a scan speed of 12 m/s, and a fill of 1500. The second pass lowered the power to 200 W, switched the pattern to circular, and cleared away the remaining base coat.

The results were impeccable: the wood was barely touched. We also captured some fascinating images as proof. When the laser encounters contamination, it absorbs and reflects the light, but when it reaches the wood, the beam simply is not absorbed. Take a look at the photos.

Does anyone know what settings I can use for paint removal on a continuous wave machine? Thanks

What would you recommend getting as a first tool: a CW or pulsed laser, to test the market and see what types of jobs customers actually need?

Hi everyone,
We are currently testing graffiti removal from a very porous/textured exterior render and are struggling to find the right parameters.
Our machine is a 300W pulsed fiber laser with a JPT 5 mJ source (1064 nm). We have F160, F210 and F330 lenses available.
We have tested a wide range of settings: different power levels, frequencies, pulse widths, scan speeds, fill spacing and scan patterns (Sine, Spiral/Weld, Rectangle/Rec2).
The laser removes the main/top layer of the spray paint, but a green/blue shadow remains deep in the porous surface, as shown in the attached photo.
If we become more aggressive with the F160/F210 lens, it sometimes looks like we are heating/baking the remaining pigment or binder into the surface and creating a darker discoloration rather than actually removing it.
So far, the F330 lens with higher scan speeds seems more promising, as it appears to remove the paint more gradually without affecting the substrate as much.
Has anyone here successfully removed spray-paint graffiti from this type of porous render/stucco using a 300W 5 mJ pulsed laser?
I would really appreciate any settings you have had success with, particularly:
• lens / focal length
• scan pattern
• power %
• frequency (kHz)
• pulse width (ns)
• scan speed (mm/s)
• scan width/height
• fill spacing / overlap
• number of passes
Also interested to hear whether you normally stop once the surface coating is removed and use a graffiti shadow remover/chemical treatment for pigment that has penetrated the pores, rather than continuing with the laser.
I know settings aren’t directly transferable between different laser sources and optics, but even some starting points from people who have dealt with similar graffiti would be extremely useful.
Photo attached shows one of our test areas.
Thanks!

I got a laser machine with a 6mm push to connect outlet with a 6mm hose. How do I connect to a 1/4 inch airline

Muy buenas soy nuevo en laser y me han pedido el restauro de una estatua de chapa metálica forjada y soldada (placas de acero)
Ahora la estatua mide 4 mt x2,5 de ancho.
Yo calculo unas 8/ 10h de trabajo.
Es demasiado?
La estatua está bastante recta no tiene muchos detalles.
Y por una con detalle de 2 metros?

Ah es para un ayuntamiento.

wow, I love the feel

We had a project over the weekend to completely strip a 100+ year old Douglas Fir 24’ extension ladder for a fire department that was restoring it, along with the very truck that it was used on for their museum!

I’ve done some research, but sometimes I get conflicting information so I’m just reaching out to the people here who have more knowledge and experience than me.

I’m gonna be purchasing my first laser cleaning machine and would primarily be working on vehicles whether that’s light to medium rust/paint removal/Bondo or even just cleaning parts that are covered in crime grease carbon etc. But obviously would be open and interested in using the laser to clean whatever I can within its limitations.

The metals that I believe I would be the most commonly encountering would be aluminum, cast-iron, stainless steel, possibly chrome plated metals, steel

The supplier I’m speaking to recommended me the 5MJ. But I’ve heard that the 15 MJ might be better for automotive work.

So which would be better for my applications and why any advice would be greatly appreciated.

Question for people who work in mobile laser cleaning services:
How do you handle the fumes and dust when working at a customer’s location?
What kind of fume extractor, filters, ventilation or respirator/PAPR do you use?
Do you normally:
work outdoors and let the fumes disperse,
use a HEPA + activated carbon extractor,
exhaust the air outside,
or use another setup?
I’m planning to start a mobile laser cleaning service with a ~300 W pulsed laser, so I’d really appreciate advice from people who are already doing this professionally.
What setup has worked best for you in real-world jobs?

Laser cleaning machine removes rust and dirt from truck surfaces.

I'm helping my dad choose his first laser cleaner and I want to make sure he buys the right machine the first time instead of wasting $15k+.

His main business would be:

• Full kitchen cabinet/armoire refinishing (remove stain, lacquer, paint, clear coat)
• Staircases, doors, trim and other wood restoration
• Possibly offering services to local manufacturers by cleaning aluminum injection molds (plastic residue, carbon, etc.) without damaging the mold

We've been looking at the SFX 300W air-cooled pulsed laser (not continuous wave), but before buying I'd like advice from people who actually own and use these machines.

Questions:

1. Is 300W the current sweet spot for this type of work, or would you recommend going 500W instead?
2. Is air-cooled the right choice or should we spend more for water-cooled?
3. Which laser source would you buy today? (JPT? Max? Raycus? Other?)
4. For cabinet refinishing, how important is pulse energy (mJ) versus simply buying more watts?
5. Can one machine realistically excel at BOTH:
   • wood refinishing
   • aluminum/plastic injection mold cleaning or are those actually two different use cases requiring different specifications?
6. Which brands have the best long-term reliability and North American support? (SFX, Hanten, P-Laser, Adapt Laser, etc.)
7. If you were spending $15k–25k today, what exact machine would you buy and why?
8. Are there any options or accessories you wish you had ordered from day one? (different lenses, fume extractor, rotary, longer fiber, etc.)

My goal is to buy once and keep the machine for many years, so I'm much more interested in real-world experience than marketing brochures.

Thanks everyone!