This time we are making something bigger, a katana! There are so many characters with katanas in anime. Unfortunately, you can’t bring a real katana to a convention. That is why we are going to make our own foam katana. Convention friendly and safe.
Drafting the pattern
For the first part you will need: 10mm semirigid foam, a cutter, a rotatory tool, a marker and sandpaper
I happen to have a bokken so it was pretty easy just to copy the form for my pattern. As this is not something you find at home I wrote down its measures for you. My katana was 101cm long, with a maximum width of 4cm at the base and 3cm at the tip and slightly curved at the end. The original tsuba (or guard) was 8cm but it wasn’t good enough for my design so I modified it.
I grided my paper and started drafting my pattern. I liked it, but it wasn’t long enough so I had a little trick, you see the red dots? that’s where I cut my pattern and added an extra centimeter so it was now 18cm long.
First steps for the foam katana
Now cut the pieces in your 10mm foam. A good trick is to pin your pattern down and draw the shape with a marker. Use a cutter and a ruler to cut it out. I also used a soldering iron to do the holes in the guard but it is not necessary for this project.
As I happened to have 5mm foam at home I decided to glue it to the handle with contact glue on both sides of the sword. This will make your handle thicker. You can also glue two parts of 10mm foam to make your handle and then attach them to the blade. Make sure it is a strong hold or it may break.
Carving your foam katana
Now the fun part, draw how deep you want to sharpen your weapon, a good trick is to hold your finger against the foam to make straight lines with even width (my daddy told me this trick)
And now is the time to use the power tool! You have to sand your edges until you are happy, take your time to make it right. Also, remember to take breaks if the surface is too big, the tool doesn’t work as well if it is overheated. If you want to make it even, use sandpaper to finish it, it will make any bump disappear.
Covering your foam with worbla
Unfortunately, using just foam is not enough to keep your katana straight. In order to solve this you need to use a thermoplastic cover like foam. This will keep your weapon straight.
Using a heatgun, cover your katana with black worbla or a similar thermoplastic. Use a flat stick or other tools to flatten the sides and cut the excess. Remember that worbla becomes really hot. Make sure all the foam is covered and reheat again if necessary. You can add extra details using several layers of foam and covering them with worbla and also rolling the foam to create ridges.
Final result
Finally, this is how the katana looked when I finished. I will show you how to seal your worbla with glue and how to paint it in another tutorial.
