Easiest Mess Free Foam Cutter Ever




Introduction: Easiest Mess Free Foam Cutter Ever

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The goal of this ible is to show you how to make a simple and inexpensive foam cutting blade. I've already posted how to make hot wire cutters, and there are hot knives and scoring method, but I have found what is probably the easiest and cheapest way to cut long perfect piece for uses like home insulation.

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Step 1: Material

What you will need to make your own foam cutting blade is...

Step 2: How It Works

The end goal is to make a knife style edge on the blade so that it sices, but without the teeth it can't just rip chunks out. That will get the cut started. For the slicing, we rely on the heat from the friction, this is why we don't just go really slow with a toothed blade. Teeth on blades have a kirf and gullet to help clear chips and let air cool the blade. With no teeth, we will be heating up the blade in the foam.

The video above demos my two kinds of foam cutters, each being used for their strength.

Step 3: Grind the Teeth Away

Find a spot to secure the blade in place, and start grinding at a 45 degree angle. Flip it, and repeat. At this point you should now be able to remove the teeth.

Step 4: Smooth and Sharpen

Grind dead on to the bumps left of what the teeth were. After, give it another pass at 45 degrees to give it back its sharp-ish edge.

Step 5: Cut Foam

That's it, you can now do perfect, long, mess free cuts in foam blocks. I also made a 10 inch version, which you can see in action in the video above.



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    9 Discussions

    While grinding do you allow the blade to spin slowly using the screw/washer combo to control the speed? Or do you do 1 section at a time?

    2 replies

    I did a bit of both because it was amusing, but it's faster section by section. I ended up mostly keeping it fixed.

    Actually, for an update, I ended up running the blade barely sticking out ouf the table saw, and using the grinder (off) to finish it up so that I could make it more even to reduce the wobble.


    2 years ago


    I thought the cleanest way was the hot wire method (pretty easy through). Here's another way. Thank you.


    1 reply

    I guess they are equally clean as they are both mess free, but I really like how this is a no fuss, no maintenance type of tool. The hot wire is certainly better for complex shapes, but can snap, bend, and needs proper voltage control.

    I just finished making the video of part 2 with the larger blade actually; I added it in the last step. As well, there is a quick segment in the part 1 video where you can see me using the 5" version.

    start with a pizza cutter? might take less time to mount an already smooth blade than to grind the teeth out

    1 reply