Many people ask us if metal engraving with CO2 laser machines is possible. In fact, metal engraving with a CO2 laser machine is possible using a process in which paints react chemically as the engraving takes place. This is one of the cheapest and quickest ways to engrave metals.
What kind of chemicals can I use to engrave metals with CO2 Laser?
Chemicals used for metal engraving with a CO2 Laser machine include: Brilliance Laser Inks, Cermark & LaserBond. All of these have a solution for engraving metals, either through a paste to apply on the metal or through formulas to prepare and apply in spray cans.
This type of chemical solution is one of the best for metal engraving although it is quite expensive the results are excellent. Keep in mind speed of both drying and engraving is not as good as engraving done with fiber marking machines.
Related Post: 5 Best Fiber Laser Engraver for you
What types of Metals can be Engraved
A CO2 Laser machine can engrave a variety of metals, but the most common are stainless steel, steel, aluminum, some anodized metals, copper, and brass.
These are the most common metals to work with and yield the best results. However, there are many other types of metals and alloys that can yield a poor outcome.
For example, silver, gold, and others cannot yield the best results, as per the metals mentioned above. For these metals a fiber laser marking machine is the best option. I recommend the fiber laser marker because it was built to handle metals with high melting points and high hardness.
What Metal Materials can be engraved directly without any chemicals
Anodized Aluminum and anodized steel are both very common metals used in advertising products such as pens and USB drives, as well as some mobile phones. These metals are coated with a paint that can be removed using the CO2 Laser machine.
The laser machine has a limitation of removing a small section of the base color due to the laser’s ability to remove a large part of the paint, but not all of it. This creates an effect that leaves anodized metals with some residual color.
Consider the following example: if we were to engrave a dog tag in red anodized aluminum, the name of the dog and all the contact information of the owner would have a reddish color through the whole engraved area. Thus, the engraving will not have a completely clear and clean appearance.
Stainless Steel is the best metal to engrave with CO2 Laser
Since stainless steel has a lower thermal coefficient than aluminum, it is the best material for engraving on a CO2 laser machine. This means that the light beam has less reflection when compared to the reflection of aluminum. When the beam of light generated by the machine has less reflection that means that it’s better absorbed by the metal. The results is that it can engrave with a darker color and with better quality.
Related Post: Best methods for laser engraving stainless steel
Will the engraving fade over time?
Metal Engraving with the correct parameters and material will not fade or erase. Even a chemical etching on smooth metal will not fade or erase. Usually metal engraving is done at a slow speed with high power and the only way to remove it is with sandpaper.
Parameters are also very important
Returning to the previous point and especially the fact that metal reflects light. A good design and proper engraving parameters are important for getting a good result. But when it comes to engraving on metal, a good parameter setup makes a big difference between an engraving that erases easily and one that does not. The latter even applies to low wattage machines.
The following steps are required for a CO2 laser machine to engrave onto stainless steel with a metal marking spray.
- Prepare your metal product for engraving.
Ensure the metal is clean (grease will reduce the spray’s effectiveness) and dry before you begin. Remove any surplus parts of the item that may get in the way when engraving, and cover any parts you don’t wish to be sprayed.
- Apply the metal marking spray.
After your product has been prepared, spray the metal surface with metal marking spray. Instructions on how to apply the spray can be found on the aerosol can, or can be obtained from reputable suppliers. An even coat of the spray will produce more consistent results.
Before moving on to the next step, the spray must dry completely (this typically takes a few minutes, but will vary depending on the type and thickness of the spray). Spraying does not need to be very thick, but too thin of a layer may result in patchy engraving.
- Laser engrave on the metal.
Once your metal product has been loaded into your laser machine, you can engrave your design on the coated surface. Trial and error can be used to determine what settings are required for the metal, or the supplier of the metal spray, or your laser machine supplier may be able to help with the settings.
- Clean the metal.
You can gently wash the remaining spray off your product by using clean water and a soft cloth if needed.
It’s that simple – you are now ready to present your finished product to a client, package it for sale, or use it as you wish.
In the below YouTube Video you will learn how to laser etch stainless steel tumblers using Brilliance Laser Inks spray.
The best Metal Marking Aerosol for CO2 Lasers:
In summary it is possible to engrave some metals with a CO2 Laser using the information and products detailed above. The best option however would be a fiber laser marker which is capable of engraving all metals with incredible detail and quality. Here is a list of the 6 best laser engravers that would work well with most metals.