How To Prevent Scorch Marks When Laser Cutting

Anybody who has given CO2 Laser Engraving a shot will know that there is one thing that can always go wrong – scorch marks!

Burns and scorch marks on the edges of an engraving can ruin the overall look of what you’re making and can be difficult to avoid, especially if you’re new to the process.

Depending on the material you have, this might be something that is unavoidable. That said, there are some things you can do to minimize risk, and a few important rules to follow.

How To Prevent Scorch Marks When Laser Cutting

If you find yourself running into this problem – don’t panic! We’re here to help! In this article, we’re going to run you through everything you’ll need to know about preventing scorch marks whilst laser cutting.

We’re going to take you through the types of wood to avoid, techniques, and tips to help you get perfect engravings every time.

We’ve also made sure to include a short Frequently Asked Questions section that will help answer some other questions, as well as break down some of the more technical terms used in this article.

Why Do I Keep Getting Scorch Marks On My Engravings?

We’re going to be straightforward here – the main reason you’re getting scorch marks on your engravings is probably because of the type of wood you’ve chosen. But how exactly does this happen?

The most important thing to realize here is how a laser cutter works, and that it’s not caused by the actual beam.

When you engrave, fumes and debris are drawn out of the cutter and can embed into the wood you’re cutting into.

These fumes make an impression on the wood and black marks will appear around your engraving. This isn’t so much your wood being damaged, but that it is being stained by the fumes of your laser cutter.

Thankfully, there are a lot of different ways you can go about preventing this. In the section below we’re going to break these down for you including wood choice, your engraver’s settings, coatings, and application tape.

Method 1. Application Tape

Often, the best solution is the most simple. Scorching can easily be prevented with a very simple layer of transfer or masking tape. All you need to do here is add a layer of tape onto the plywood before cutting.

What this means is that the wood will be protected and any fumes will instead imprint onto the tape. Once you peel the tape off, you’re going to have a clean engraving without any nasty marks.

We typically suggest something simple like this product here.

Method 2. Laser Cutting Settings

Here, you’re going to want to make sure you have the right settings to ensure your laser isn’t too close or too focused on the engraving you’re trying to make.

The most important thing to note for this step is that there are a lot of different laser cutters with a lot of different settings, so there’s no easy answer we can give you.

But one thing you should know is that you want to make sure you’re getting the right focus distance.

Before committing to an engraving and possibly ruining a cut of wood, we recommend trying out a few different settings to minimize your laser’s contact with the surface.

Remember, a tiny error in focusing distance can create scorch marks so make sure you’re careful!

You also want to make sure you’re picking a setting that properly corresponds to the type of material you’ve chosen. Softer woods need less intense heat, and so on and so forth.

Generally, if possible, you want to try and see how your machine will interact with wood before committing to engraving.

This skill can come with time, but it is always a good idea to have a piece spare to practice on.

Method 3. Choice Of Wood

The unfortunate truth is that not all wood is equal. Some types are much more suited for laser cutting than others.

We’d like to start off this section with the general rule of picking softer woods with simplistic grain patterns. Glue is the real enemy here, and generally the more glue content the more difficulty you’re going to have.

Below we’re going to discuss some of the different wood choices you have available.

Soft Woods

If you’re looking to pick a safe option, it’s probably best to go with very soft wood. Here you can choose something like basswood or alder.

The soft composition of these woods allows for you to engrave on a low-intensity setting, meaning there will be much less chance of scorch marks appearing, providing you do everything else right.

Plywood

There’s a fair chance you’re going to have plywood as a material to work with at least once if you’re going a lot of engraving.

Unfortunately, plywood can be quite a tough wood to work with and you’ll often get scorch marks if you’re not careful.

Reclaimed plywood can have a whole host of problems including glue content, especially if you don’t know where it’s come from.

Hard Woods

The main problem with hardwood is that their grain composition means you’re going to have to use a higher setting in order to get a good engraving. More heat means more chances for scorching to occur.

A Note On Resin

Another aspect of wood choice that can trip you up here is resin content.

The amount of resin or sap within the wood is going to mean the difference between a clean engraving and possible scorch marks. Higher resin typically means scorch marks, low resin means a much cleaner cut.

Method 4. Coatings

One thing you can do is properly coat your wood before starting your engraving. Coating your wood involves covering it with a thin layer of varnish and then letting it dry.

If you combine this with step 1 adding masking of transfer tape can create additional protection.

How To Prevent Scorch Marks When Laser Cutting

Final Thoughts

So there you have it! There are a lot of different reasons why your wood might be getting scorch marks when you engrave, but generally, it’s because of the quality of your wood.

Make sure you think carefully before committing to a purchase, and that you have double-checked the settings of your laser so that they are appropriate for the wood you’re using.

If you need to engrave a type of wood that you know will be problematic, take extra measures to avoid scorch marks.

We hope that this guide has given you some insight into how you can avoid scorch marks when engraving with a laser cutter and that you now feel a lot more confident about the whole process.

If you still have some questions, check below for our Frequently Asked Questions section for answers! Happy engraving, we hope that you’re not able to create perfect engravings without the nasty scorch marks!

Frequently Asked Questions

How Can I Remove Scorch Marks?

Generally, it’s much harder to undo scorch marks than it is to take preventative measures and stop them before they happen, but if you do find you’ve made an otherwise great engraving with some scorch marks, then there are a few things you can do to mitigate damage.

We’re going to briefly outline them for you below.

Sandpaper

One thing you can do is use a small piece of sandpaper to gently rub away some of the marks around your engraving.

Make sure to be careful so that you don’t ruin the engraving, and used fine-tooth sandpaper if you can.

Alcohol

Take some denatured alcohol ad place it onto a cloth. From here, gently work around the edge of your engraving where there are scorch marks and try to see if it removes any of the stains.

Acetone

Like the step before, simply add some acetone to a cloth and clean up the edges.

Should I Sand The Wood Before Engraving?

Typically, an engraving is one of the last steps you’re going to take in any project, so you’ll want to make sure your piece is adequately sanded before you begin the engraving.

However, you can also sand a little bit after around the edges of the engraving to make sure it all looks clean, and to remove any potential stains.

What Does A Laser Engraver Do?

A Laser Engraver will vaporize materials into fumes to engrave permanent marks into the chosen material.

Wood is one of the best materials to work with when using a laser cutter as it is very soft and doesn’t offer that much resistance.

Michael Moore

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