Laser Cutting Wood: 3 Ways to Prevent Smoke and Burn Stains

When using laser cutting to engrave wood, you need to be careful of smoke or burn stains that may appear on the edge of the engraving. These stains are not from the laser itself, but are due to the smoke produced from the combustion action caused by the laser. These burn and smoke stains are difficult to avoid; however, they are not completely unavoidable. Here are 3 ways you can prevent the edges of the wood from getting stained.

Cover the Surface with Masking Tape

Before laser cutting the surface of the wood, cover the entire surface with masking tape. The masking tape will prevent the edges of the engraving from getting stained and will not leave any residue behind. The tape is also cheap and easy to remove. Do keep in mind that it can be rather time consuming to remove all of the tape for detailed engravings.

Low-tack masking tape is usually sufficient for most types of wood; however, high-tack masking tape may be needed for wood that has both a high moisture content and an uneven grain structure. Low-tack masking tape will peel off from the surface of these types of wood too quickly, and may not offer the amount of protection needed.

Back Out the Focus of the Laser

Instead of relying on automatic settings, set the settings to manual. You want to drop the focus to as low as possible before you begin any engraving work. Try out different focuses on a spare piece of wood in order to determine the depth and thickness of the engravings that best suit your needs. A lower focus may still be able to provide you with the results that you seek in terms of sharpness without the high levels of smoke that are usually emitted at a higher focus.

Remove Burn Marks Using Denatured Alcohol

If you have tried all of the techniques mentioned above and still see some minor burn marks and stains on the edges of the engraving, you might be able to use denatured alcohol to remove the stains. Denatured alcohol has been highly recommended for cleaning and restoring wooden furniture; however, it can also be used to remove burn stains. Apply a little bit of the denatured alcohol onto a cloth and rub at the stain to remove it.

Laser cutting wood does not necessarily have to leave any burn marks or stains. Take these precautions and you'll get clean engravings without the mess.