Laser engraving is a handy and practical technique used to create permanent marks on various materials including but not limited to textiles, acrylics, wood, natural stones, metals, etc. From engraving company logos on products to making personalized gifts, there’s plenty of things you can create with a laser machine. Wood is particularly loved by most beginners due to its versatility and availability. Never mind the fact that it can be a bit challenge to working with.
So how do you laser engrave wood? Well, laser engraving on wood happens pretty much like in other materials – a laser beam is passed over the material which heats it up and vaporizes it. The result is a smooth, clean, and perfect engraving that cannot be imitated by other woodworking equipment. The main difference between laser engraving wood and other materials is that in wood, it is typically a sublimation process. This means that as the laser beam is passed over the material, it is converted via combustion into a gaseous state. Expectedly, the process creates smoke in the processing area from time to time during laser engraving.
Because it is natural, wood has a ton of inconsistencies that can be problematic when engraving. Fortunately, once you get the hang of things and discover the right power settings and speed for different wood types, you will end up with perfect engravings. Wood is quite adaptable. Not only is it easy to cut and engrave but it comes in lots of different varieties, shapes, and sizes.
For best results, you have to know how to appropriately focus the lens. For instance, you can achieve a white engraving as opposed to the usual brownish-colored one just by setting your laser accordingly. The settings of your laser engraver and the type of wood used also to determine the outcome of your project. Other important considerations to take note of when engraving on wood include material preparation, using the right optics and compressed air, and cleaning of the surface.
How to choose the best wood for laser engraving
The type of wood you plan on cutting into is of the utmost importance when laser engraving on wood. For instance, a bamboo cutting board will not engrave the same way an oak barrel will. Ideally, softwoods such as redwood, western red cedar, southern pine, and balsa don’t need high laser power to engrave. They also cut quicker and result in lighter engravings. On the flip side, hardwoods such as dense wood, Brazilian ebony, snakewood, and African pearwood require more laser power to cut through and engrave. These also give off dark engravings. Ultimately, the type of wood used will affect the final output.
Most CO2 lasers can handle all types of wood but there are plenty of other machines that are best suited for certain wood types. For instance, if you own an industrial laser engraver with the capability of engraving on harder materials such as stone and metals, laser engraving on wood will be a walkover.
Should the wood be sappy or dry?
Apart from the type of wood to use, the resin content is also very important when selecting the best wood for laser engraving. Wood largely burns lighter or darker depending on its sap or resin content. For woods with low resin contents, the laser beam vaporizes the wood and leaves a minimal burn. If the resin content is on the high side, the laser beam will consume the resin and dig deeper into the wood leading to a darker burn. In case you are wondering which wood types have a high resin content, cherry and alder top the list every time. Both are excellent for light color engraving projects. However, cherry tends to have a high level of streaking but still makes for an excellent material for wood engraving projects.
Other important parameters worth considering
As we have already established, the type of wood plus its resin content are important factors for any laser engraving on wood projects. But there are other equally important factors worth mentioning;
- Engraving parameters: if you want a darker engraving on wood, you can increase the defocus of the laser beam. Doing this will not only decrease the density performance of the laser but it will increase the spot size of the laser as well. The result is that more wood will be burned as opposed to passing the beam directly in a gaseous form. Unfortunately, this fantastic strategy loses some engraving details in the process
- Cutting parameters: you can determine the cutting quality of your laser by adjusting your cutting parameters accordingly. To achieve this, run a test of what to expect by drawing a rectangle with two rounded corners on a piece of paper. Send this to a laser. Begin with a cutting speed of 2-5% and a high performance for a 3mm-thick wood. Gradually reduce your cutting speed until you arrive at your desired quality.
- Material preparation: when you run a wood laser on a wooden material, you will notice a cloud of sticky dust forming on the engraved object. This is not only annoying but can easily cause your machine to malfunction. To counter it, glue an application tape over the working surface to act as a temporary protective layer. When you are done engraving, simply remove it and clean your object. Application tape is used for large surfaces but isn’t ideal for very small engravings and photo-engraving. This is because you will need to remove hundreds of small parts after the task is completed.
- Use the right optics: as mentioned before, wood engraving is basically a sublimation process. The choice of the correct optics coupled with precise focusing is paramount. The rule of thumb is to use a shorter focal length on the lens to attain finer details. A 1.5” to 2.0“lens will get the job done for most wood engraving tasks. However, when cutting through wood, the material thickness comes into play. Here, the thicker the wood, the longer the lens’s focal length used.
- Compressed air: Compressed air is not entirely used on all wood laser engraving projects. However, it is highly recommended when cutting on wood. A small nozzle diameter helps protect the lens and direct compressed air on the cutting gap. This instantly removes gas and dust and enhances the cutting quality of the laser.
- Cleaning: it is easy to ignore the importance of cleaning the laser hardware and optics but it has a direct impact on the functionality of the laser machine. Wood dust is loaded with oils and resins which makes is really sticky. When it settles on the machine, it won’t be long before it malfunctions. It is, therefore, necessary to clean the laser engraver on a regular basis.
- Streaking: streaking may be lovely in zebras but it is not so in wood – especially wood for laser engraving. The reason is that it steals the attention away from the engraving rendering your efforts useless in the end. When laser engraving wood, always pick wood with minimal streaking and a smooth consistent grain. Woods with smooth and consistent grains have nominal alternating dark and light streaks. Any engraving done on such wood types looks detailed and clearer compared to the one with a high level of streaking.
- Color of wood: Since you cannot really manipulate the base color of wood, you are better off working with lighter wood. Essentially, the base color always follows the wood color. It is therefore important to consider the original color of the wood you intend to work on before embarking on the project. Dark wood typically obscures your engravings making them quite hard to see or recognize. Lighter wood, on the other hand, develops an attractive dark burn when engraved that is great for optimal visibility.
What can you create with laser engraving on wood?
Wood is the perfect material for laser engraving personalized gift items. Through laser engraving technology, you can create unique pieces by engraving names, logos, images, and prints into wooden products. These pieces can range from jewelry boxes, cutting boards, key holders, inlays for cabinets, plaques, humidors, phone cases, musical instruments, skate decks, and many more.
Laser engraving wood is high in demand because it increases the value of items. It is also remarkably impressive and easy to achieve. Since wood is quite easy to find, this would be a great material for every beginner to start their engraving business with.