Cutting EVA foam can be weirdly challenging. This guide will show you how to cut straight, curves, and how to cut circles. I will also cover the most common issues when cutting EVA foam.
EVA foam can be cut by using a box knife, a hobby knife, and even scissors. Make sure that the knife is sharpened regularly because foam dulls knives very quickly. For sharpening knives sandpaper or a whetstone can be used. A rotary tool or sandpaper can be helpful for cleaning up rough cuts.
You can find all of my EVA foam guides right here if you want to learn more.
Materials Needed for Cutting Foam
You will only need a box knife, some sandpaper, and a metal ruler to cut EVA foam. Additionally, a self-healing cutting mat and a whetstone can be very helpful for cutting foam.
Here is a full list of materials for cutting EVA foam.
Scissors
Scissors are suitable for cutting very thin EVA foam, but they may not provide clean cuts for thicker foam.
I recommend using scissors primarily for thin EVA foam and especially for intricate patterns with many curves and tight corners.
Box Knife
A box knife is the best tool for cutting EVA foam. It’s cheap and it allows for very precise cuts.
You can even get a smaller box knife or a hobby knife for tight corners or very fine cuts.
Cutting Mat
I highly recommend getting a self-healing cutting mat. It will serve as a perfect surface for cutting.
Self-healing means that the mat will slowly “heal” any cut you inflict on its surface. This will ensure that you can use the mat for a very long time.
Buy a cutting mat right here on Amazon.
Ruler (Metal)
A metal ruler is a must-have when you need to do a lot of straight cuts.
You can also use a metal T-square if you need to make a lot of very accurate cuts.
A metal ruler can be bought in your local arts and crafts store or here on Amazon.
Sandpaper or a Whetstone
Lastly, ensure you have some fine-grit sandpaper or a whetstone on hand to keep your box knife sharp.
Working with EVA foam can quickly blunt your knife and a dull knife leads to messy cuts, so maintaining sharp tools is crucial.
I personally prefer sandpaper for sharpening. It’s effective, and you don’t need to invest in an expensive whetstone.
Sharpen Your Knife
The most important part of cutting EVA foam is a sharp knife.
I recommend sharpening your knife every two cuts to ensure it remains sharp.
To sharpen your cutting knife, you can either use a sandstone or fine-grit sandpaper. Hold the knife at a 30° angle and run it back and forth over the sandstone’s surface.
Sandpaper can also be used in the same manner.
Keep in mind that EVA foam can quickly dull your knife, leading to less precise cuts. Dull knives result in less clean cuts.
While you can fix this by sanding the cut area later on, it’s best to avoid the extra effort by regularly sharpening your knife.
When cutting the foam, try to maintain a straight path and move slowly, following the guidelines as closely as possible. A cleaner cut will make it easier to later glue the pieces together.
A metal ruler is very helpful to do straight precise cuts.
Use Scissors to Cut Thin Foam
Scissors can also be used to cut thin foam, especially when you need precision for cutting curved lines or circles.
However, it’s important to note that foam tends to dull scissor blades rapidly, necessitating regular sharpening.
How to Cut at an Angle
Occasionally, you may need to cut your foam at an angle to achieve sharp corners.
To cut EVA Foam at an angle, you just need to hold your cutting knife at the desired angle while cutting the foam. This skill requires some practice to master.
It’s advisable to move slowly and maintain a steady hand. If you’ve sharpened your knife, you should be able to cut the foam with minimal effort.
When cutting foam at an angle, a little bit of math is involved, but it’s quite straightforward. All you need to do is divide the desired angle by 2 to determine the angle at which you should cut the foam.
For example, if you aim for a sharp 90° corner, you should cut the two meeting edges at 45°.
How to Cut Curved Lines
Cutting curved lines can pose a challenge, particularly for those new to crafting with EVA foam.
When working on curved cuts, aim to maintain the cutting knife as straight as possible while following the line closely. It’s advisable to cut slightly to the left of the line, leaving a small margin. This margin will come in handy for refining the cut later.
It’s common for curved cuts to be less clean initially, and there’s no need to worry. I personally use a rotary tool to tidy up the cut, but sandpaper can also do the job. Having that small margin when cutting the piece will allow you to sand it down to the guideline effectively.
How to Cut Circles
Circles are even harder to cut accurately.
The technique for cutting circles is similar to that used for curved lines. Begin by cutting along the guideline while leaving a small margin. The initial cut may not be perfect, but you can easily refine it using a rotary tool or sandpaper.
Learn more about how to sand EVA foam right here.
If you need two circles of the exact same size, you can follow this method: roughly cut out two circles, temporarily secure them together with double-sided tape, and then use a rotary tool to sand them both to the desired size. This ensures matching circles with precision.
Cut EVA Foam With a Laser Cutter
EVA foam can also be cut with a laser cutter. The foam should be held in place by magnets or some clamps to ensure that it does not move while the laser is working. Ensure that the laser is set to the right cutting speed and power. This will ensure that the foam doesn´t melt when cut by the laser.
It´s also important to either have a ventilation system that gets rid of the fumes that are being created when cutting EVA foam or to wear a protective mask. Even though EVA foam is not toxic it’s also not healthy to inhale these fumes.
You can determine the right speed and power of your laser by doing some test cuts. Test different settings until the cut looks clean.
A honeycomb cutting surface can help with smoke residue on the bottom side of the cut foam piece. This is because the honeycomb pattern allows for the smoke to escape on the bottom of the laser-cut piece.
Does EVA Foam Rip Easily
EVA foam does not rip easily. Even thin EVA foam is pretty difficult to rip. However low-density EVA foam, also known as LED foam, can be ripped easily. Low-density EVA foam should not be used to build props except if the prop is supposed to light up. Generally, the higher the density of EVA foam is the harder it will be to rip it apart.
Disclaimer: This article has been written with the assistance of artificial intelligence (AI) to enhance its readability and grammatical accuracy. The content and information presented in this article are entirely original and originated from the author. The AI was used solely to rewrite certain sections of the article for the purpose of improving clarity and coherence, without altering the substance or meaning of the content.
