Cut strait lines in foam

I’ve got some high density foam and the age old tomato can cutting is going great. I’m wondering what the best way to cut strait lines in the foam is? i.e. I need rectangles of various size. Note that one of the rectangle sizes is a bit narrow: 1"x6". I’ll be using this slot size to fit test tubes that will house string… Yes, it will be awesome IMO.


So far I’ve seen a technique employing a “hot wire”, but I don’t think that this works for the type of soft foam I’ve got. It looks to be a successful technique on more styrofoam-type material, but I suspect this would not work with the type of sponge-like foam I’ve got.

No advice for cutting a straight line. But yes you are correct, the hot wire cutter is primarily used to cut styrofoam.

I used a serrated bread knife to cut mine.

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A band saw is excellent for cutting straight lines in foam, if you have access to one…


At some point I had typed up how I cut my foam. I believe it was in a thread that TotalArtist had started a long time ago.

This is just a small case I did. Holes have been cut using a Dremel and wire wheel attachment.

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I never thought of using a dremel. Can you explain more. I’m thinking of making a few more boxes and i’m always looking for ways to get the cuts exact.

As to the OP, depending on the length of cut, I’ve used a long serrated bread knife for longer sections and a small paring knife for shorter sections. Despite what kind of a knife you use… go slow and don’t press hard. Let the knife do the work. Once you start pressing hard and crushing the foam, you start to get crooked cuts. You can always mark the underside with a sharpie so you have a guidelines for cutting.

Good luck.

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I have it all played out in the thread I mentioned above.

Short version is trace your circular lines on foam. Plunge the wire wheel attachment into center and work out from there. Switch to sanding drum to clean up.

Straight lines I use a scrapper blade available at HD. In the rug department they are a one sided blade used for something. About 4 inches long I usually grind a point to the sharp side on it. Plunge straight in and cut slowly in a vertical motion.

Coping saw blades work well too. Fine tooth is better.

I believe one of these is the thread you were talking about,47854.0.html,60955.0.html,64675.0.html

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Second one. Was thinking third though!!

That’s not bad… Can you imagine doing fine inner work using this technique as I am looking for?

Sure. There are a ton of ways to utilize the dremel.

Laser cutter. If u know the right person.

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