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How to Make an EVA foam Dagger

I designed and built this dagger so it would be strong yet still very safe. I wanted a foam weapon that could be used. And it doesn't have any kind of stick or pipe in the middle which makes it much safer. Yet, it is still strong and durabe.

I also have a video tutorial for this project at the bottom of the page.



About this project: This is a neat little project that is easy to make. And it uses EVA foam. If you are not familiar with EVA foam it is the stuff used in yoga, dojos and gyms as floor matting. It is flexible, strong and easy to work with. This dagger can be used for fun, combat, Cosplay or LARP yet still is very safe. And you don't need a heat gun for this build.

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Tools and Materials:

  • 1 sheet of EVA foam
  • Hot glue or adhesive like 3 in 1 glue or Barge Cement
  • 1 cereal box
  • Your choice of color paints
  • Plasti-dip to make the rubber handle (optional)
  • X-acto knife

Quick notes:

When using an x-acto knife to cut the foam be sure to replace the blade often. It makes a really big difference. And unlike foamboard you should try to cut all the way through the EVA foam with a single pass. It will make for a cleaner edge.

Glue testing:

I tested a few different glues when making this knife. Here are my results:

Glue test

I tried four different adhesives, and I did them flat sides, dimpled sides and even on edge. The picture shows a portion of the test.

My results are that elmers glue is out. Don't use it or any other type of non-toxc white PVA glue. Doesn't work.

These adhesives worked well:

  • 3-in-1 glue
  • Barge Cement
  • Hot glue gun

And if I had to choose my guess is that the Barge cement is the best. But I would go with hot glue, for this project anyways. It worked quite fine and I love the fact that there is no waiting for it to dry.


Now Let's Get started:

Draw out your knife on cereal box cardboard. This is important. It is a strengthening part of the knife. Draw it bulky and beefy. If the blade or handle are too thin the knife will not be durable.

Draw out your dagger


Go ahead and cut that knife out.

The template

Use that as a template and trace two on foamboard. Trace one, then flip over the template and trace a second one. It is important to flip the knife template over when tracing the second one. This will insure a better assembly.

Trace onto eva foam


Then go ahead and cut them out.

Glue it all together

And glue all three pieces together with the cardboard piece right in the middle.

It is glued


NextOkay! Continue with the tutorial and we will paint and decorate it. You can also watch the video tutorial below.



The Video Tutorial is here:


EVA foam

EVA Foam Interlocking Anti-Fatigue Foam floor Mats


  • Each pack comes with six new Black tiles.
  • Each tile measures 2' x 2' for a total of 24 square feet per 6 tiles.
  • Thickness for each tile is 3/8" or 10mm.
  • Borders are included in each pack.
  • Provides a cushion to hard floor surfaces in gyms, exercise rooms, trade shows, playrooms and more.


Plasti Dip

Black Plasti-Dip - 22oz dip can


3 in 1 glue

Beacon 3-In-1 Advanced Craft Glue, 4-Ounce


xacto knifeX-acto designer series knife #1 blade




Hot glue gun

Will's Favorite Hot Glue Gun

Surebonder PRO2-100 100-Watt High Temperature Industrial Glue Gun, Black