FDA
FDA 21 CFR 1040.10 - Laser Product Performance Standards
Alessandro MorettiPh.D.Italy
Laser-Based Additive ManufacturingPublished
Dec 16, 2025
Oak Laser Cleaning
I've seen oak stand out in restoration work because its tough, dense grain absorbs laser energy without splintering or losing structural integrity, reviving aged surfaces in furniture and heritage pieces beautifully—though you must limit passes to prevent surface charring.
Laser-Material Interaction
Absorptivity
0.88
0.8
0.88
0.95
Absorption Coefficient
4.5e5
m⁻¹
1e5
4.5e5
1e6
Laser Damage Threshold
2
J/cm²
1
2
5
Thermal Shock Resistance
1.5
MW/m
1
1.5
2
Reflectivity
0.12
0.05
0.12
0.2
Thermal Destruction Point
650
K
600
650
700
Vapor Pressure
100
Pa
10
100
500
Thermal Destruction
280
°C
226
280
642
Specific Heat
1,380
J/kg·K
1.3
1,380
1,554
Laser Reflectivity
0.12
0.02
0.12
0.44
Thermal Conductivity
0.17
W/m·K
0.04
0.17
0.4
Thermal Expansion
4e-6
K^{-1}
1e-6
4e-6
5.8e-5
Laser Absorption
2.8e4
m^{-1}
0.78
2.8e4
3.4e5
Ablation Threshold
2.5
J/cm²
0.51
2.5
2.6
Oak Laser Cleaning Material Characteristics
Fracture Toughness
0.35
MPa m^{1/2}
0.26
0.35
2
Youngs Modulus
12.4
GPa
3.3
12.4
1.1e4
Oxidation Resistance
0.85
J/cm²
0.1
0.85
549
Density
720
kg/m³
0.4
720
955
Hardness
5,738
N
399
5,738
1.3e4
Corrosion Resistance
0.75
0
0.75
4.7
Compressive Strength
50.3
MPa
20
50.3
80
Flexural Strength
95.1
MPa
19.1
95.1
148
Tensile Strength
99
MPa
9.5
99
209
Porosity
0.55
fraction
0.39
0.55
0.79
Laser Damage Threshold
1.2
J/cm²
0.0025
1.2
5.4
Thermal Destruction
280
°C
226
280
642
Specific Heat
1,380
J/kg·K
1.3
1,380
1,554
Laser Reflectivity
0.12
0.02
0.12
0.44
Thermal Conductivity
0.17
W/m·K
0.04
0.17
0.4
Thermal Expansion
4e-6
K^{-1}
1e-6
4e-6
5.8e-5
Laser Absorption
2.8e4
m^{-1}
0.78
2.8e4
3.4e5
Oak surface magnification
Before Treatment
At 1000x magnification, the oak surface before cleaning looks covered in thick layers of grime and debris. Dark particles cling tightly to the fibers, filling every tiny pore with buildup. The overall texture appears rough and obscured, hiding the wood's natural details completely.
After Treatment
After laser treatment, the same oak surface at 1000x reveals clean fibers standing out sharply and clearly. Pores now sit open and empty, free from any trapped residues or dirt. The texture turns smooth and
Regulatory Standards & Compliance
ANSI
ANSI Z136.1 - Safe Use of Lasers
IEC
IEC 60825 - Safety of Laser Products
OSHA
OSHA 29 CFR 1926.95 - Personal Protective Equipment
Unknown
EPA Clean Air Act Compliance
Oak Laser Cleaning Laser Cleaning FAQs
Q: How do I remove black charring from oak when laser cleaning without damaging the wood?
A: multi-pass low fluence ablation. Keep fluence under 2.5 J/cm² with a 100W source at 500 mm/s, ablating charring while avoiding lignin carbonization. The notable 100µm spot size ensures precise control. For best results, opt for multiple low-power passes over a single aggressive one to regulate thermal input and safeguard wood integrity.
Q: What are the ideal laser parameters (wavelength, power, pulse duration) for cleaning soot and dirt from an oak beam?
A: Nanosecond pulses prevent charring. For cleaning oak beams, I suggest nanosecond pulses at 1064 nm wavelength and about 100 W average power. Start testing with a fluence around 2.5 J/cm² plus a 100 µm spot size. This approach effectively ablates soot, while essential minimization of thermal diffusion into the wood substrate notably prevents charring.
Q: Can a laser safely remove old paint or varnish from an antique oak piece without altering the patina?
A: Avoids earlywood differential erosion. Employing precise 2.5 J/cm² fluence and 100 µm spot control, a laser selectively ablates paint from antique oak. Notably, this preserves the patina by sidestepping the essential differential erosion of soft earlywood that hampers mechanical methods.
Q: Is laser cleaning effective for decontaminating mold or biological growth from oak in heritage conservation?
A: Deactivates surface mold only. UV laser cleaning at 2.5 J/cm² notably deactivates surface mold spores on oak. Yet, it fails to eradicate deep hyphal growth, thus requiring an integrated biocidal treatment. Essentially, proper HEPA filtration remains vital to control aerosolized spores during the procedure.
Q: What specific safety hazards exist when laser cleaning oak, especially regarding fumes and particulates?
A: Laser cleaning of oak at 100W and 2.5 J/cm² notably produces hazardous aldehydes and acetic acid fumes. Fine wood dust, meanwhile, creates an essential explosion risk, demanding robust fume extraction, P3 respiratory protection, and spark detection systems to safeguard operators.
Q: How does the density and grain structure of oak affect the laser cleaning process and final result?
A: The distinct alternating porous and dense grain of oak leads to differential ablation at our 2.5 J/cm² fluence. Such variation can yield a slightly textured surface, making it essential to apply multi-directional passes at 500 mm/s for uniform cleaning throughout the grain structure.
Q: What is the maximum depth of material removal possible on oak with a laser before structural integrity is compromised?
A: 10-50 microns per pass. Laser cleaning of oak remains notably superficial, stripping away only 10-50 microns per pass. Pushing beyond that endangers the cellular structure. Essential here is applying low fluence at roughly 2.5 J/cm² while capping passes to uphold the wood's integrity.
Q: How do I evaluate the success of a laser cleaning treatment on oak, and what are the acceptable post-treatment changes?
A: ΔE<5 lightening, intact cell walls. Success is notably confirmed through colorimetry indicating ΔE<5, ensuring acceptable lightening without charring. It's essential that microscopy reveals intact cell walls at 100µm resolution. Hold fluence at 2.5 J/cm² and power at 100W to avoid surface roughening.
Q: Why does my laser leave a white, ashy residue on the oak surface after cleaning, and how can I prevent it?
A: Excessive fluence chars lignin. This white residue consists of distinct micro-charred lignin, caused by fluence exceeding the 2.5 J/cm² threshold. To prevent it, it's essential to lower your laser power or raise the scan speed above 500 mm/s. A final gentle pass at reduced energy will remove leftover ash without harming the oak substrate.
Q: For which applications is laser cleaning oak most suitable compared to traditional methods like soda blasting or chemical stripping?
A: Preserves surface integrity. For delicate oak artifacts such as historical furniture or violins, laser cleaning stands out as essential. Our 2.5 J/cm² fluence and 100 µm spot size deliver micron-level precision in contaminant removal, preventing substrate loss unlike aggressive soda blasting. This distinct method suits high-value conservation, safeguarding original surface integrity above all.
