Here is how I did my sword of Future Trunks from Dragonball Z. It's mostly made out of foam and worbla.

Overview

• Materials I used
• Making the pattern
• Cutting the foam
• Inserting an aluminum rod for stability and glue pieces together
• The handle
• The guard
• Wrap the guard and the sword in worbla
• Connecting sword with guard
• Adding details
• The pommel
• Adding more details
• Paint job!
• Wrapping the handle in textile tape
• Varnishing the sword
• Results

Materials I used:

• 10 mm  high density foam → for the whole sword

Low density foam suffice if you use Worbla! I didn't have some so I used the expensive high density T.T

• Worbla finest art

• Ø 6 mm x 1 m  aluminum rod/tube → for stability

• Ø 3 cm x ≈23 cm conduit → for the swords handle

• Foam Clay → for details on the swords handle

• Textile tape → for the swords handle

Getting started!

Making the pattern

A littlebit of drawing and mathematics.

✏️ Pattern for the whole Sword

First thing I did was search for some reference pictures and then making a drawing of the sword with measures as required.
For this I determined the lenghth of the sword and started making a small drawing which fits on a single DIN A4 paper. With this I could define a ratio of 1:5 for the "small sword".  Then I figured out the other measures of the sword components with trial and error till the "small sword" looked good for me (proportions).

With the help of "rule of three" I was able to draw a "big sword" in proportion 1:1.

So I ended up with this measures:

• length entire sword: 80 cm
• blade width: 5,5 cm
• handle length: 23 cm
• handle width: 3,5 cm
• total guard length: 21 cm
• guard width: 1 cm
• max. pommel width: 5 cm

Then the "big sword" looks like this:

✏️ Pattern for the guard

After transferring the handle width I took the measures of my previous considerations and draw only 1/4 of the guard because of it's symmetry. So it was pretty easy to cut it out.

✏️ Pattern for the pommel

Here I added a little bit of paper to fill the gap after cutting out the sword.

Now that we have all patterns we can go to the cutting .

Cutting the foam

Cut, cut, cut - Nice and sharp 🔪

After transferring the patterns of sword and guard on the foam (two times for the sword) I cut it out with a very sharp (!) cutter knife. The cleaner the cut the less you have to rework the cutting surfaces.

You can use some sanding paper (grain size ≥ 150 ) to sharpen your cutting knife.

Inserting an aluminum rod for stability and glue pieces together

The rod should be positioned in the middle of the foam so I drew some lines for orientation. After that I marked the aluminum rod and cut it to desired length.

To let the rod better fit in between the two foam layers I sanded a slim gap in the middle of both layers with my dremel.

Now we are ready to glue the sandwitch together!

For this I used contact cement. I applied the glue on both foam surfaces an on the surface of the aluminum rod.
⏳...wait 10 - 15 min...
Then I first inserted the rot into the gap and pushed it properly onto the surface followed by laying the second layer on the first pushing it properly onto the surface, too.

And ready is your foam aluminum sandwitch!

Getting started for sanding

Sanding the sword into his shape!

Next thing I did was sanding the edges of the blade with my dremel like shown in the pictures below.

I recomment you to cut the rough shape with a cutter knife to reduce sanding time ;) This includes cutting the edges of the blade and the handle.

The handle

Next comes the handle. For this I inserted the foam-handle into a piece of conduit. Befor doing this the foam-handle was prepared by cutting the edges with a cutter knife. So the foam-handle fits in nicely.

I didn't sand the edges of the cut handle because you won't see the ugly surface anyway 😎

Then I marked the conduit at desired length by placing it next to the handle and cut it at the mark with a wood saw.

To reduce risk of injury I then sanded the sawn surface with some sanding paper.

And with this you have a sword handle 🥳

The guard

First I sanded the edges of the foam piece for the guard in an ~45° angle but only to ~half of the thickness (cf. the third picture).

Wrap the guard and the sword in worbla

For the worbla-step I cut worbla pieces which are a little bigger than the original shape. For the guard and the sword it has to be two worbla pieces with the same size each for the front and the back part.

Wrap the sword in worbla

First I place one worbla piece for the sword with the shiny side up heated it up, placed the sword on top of that, pressed it down, and covered the sword with the the remainig piece withe the shiny side down heating it up afterwards.

The shiny sides of the worbla pieces have to face the foam, they become sticky after been heaten up.

After the worbla has coolen down a bit I shaped it at the edges of the sword to achieve a seamless finish. I reheated the thermoplastic at some spots if it was not moldable anymore till I was happy with the result.

Wrap the handle in worbla

With the same method I wrapped the guard in worbla by sndwitching it between two worbla pieces (shiny side facing the foam!). While warm I cut the excess around the edges and poke a hole in the middle of the guard where the free space has to be. And the I shaped and shaped and reheated and shaped and shaped...till I was happy with the result.

Next I roll in the two narrow parts of the guard. Then I shaped the roll till it gets nearly round.

Connecting sword with guard

Here I placed the guard onto the handle and connected the guard with the sword by heating up the connection area and adding a little bit of worbla.

You know the procedure: shape, shape, shape, heat, heat, heat..
Then I end up with the following entity.

You still can see the seam but it will be covered soon.

Adding details

Then I added a detail-band to the connection seam mentioned earlier. Here I only covered the front part and the edges of the 2mm thick foam piece with worbla as the band is going to be placed on worbla anyway. Then I wraped the band around the bottom of the blade and shaped it till I was happy.

The pommel

Here I finally placed the conduit to continue with the pommel.

I didn't glue the conduit on the handle because it took an certain amount of force to insert the foam-handle so I wasn't in a mood of removing it again. But I recomment to glue it if it has any play.

Molding the base foam pommel

Therefore I cut an 1cm wide and 1cm thick foam piece and glued it at the end of the handle.

Since the glue-seam is showing an ugly gap I used foam clay to fill that in. Then I continued with molding the pommel with foam clay.

With this I was happy. I let the pommel dry many hours.

Wrapping the pommel in worbla

In the following step I covered the pommel with worbla and moldet it.

Adding more details

For the detail-band beneath the guard I heated up overlefts of worbla and made a sausage of it and molded it like shown in the pictures below.

Then I added detail grooves to the pommel with a metal ruler.

By this the base sword is done! 🎉

Paint job!

Here I mixed white, black, grey and blue acrylic paint till I was happy with the color. Then I painted the blade in that color with 2-3 layers.

The guard, the pommel and the details where painted in an exremely light-grey-blue color, it's nearly white.

Yes, the handle here is already wrapped in textile tape. This is because I couldn't wait to see how the handle looks with this tape. So I covered the borders with masking tape before painting mentioned parts. I recommend to wrap the handle in textile tape AFTER painting the sword, its easier and you can ignore the masking-step - be patient, not like me 🙃

In the following I rubbed some sort of metallic cream with an old sock on the sword to achieve a metal looking blade. I added a little bit of this paint on the pommel and guard aswell.

Never throw away your old socks! They are useful! - Kamui Cosplay

At the end I mixed black acrylic paint with water and covered the guard and pommel and the groove between guard and blade with this mixture. Then I removed paint overlefts with a old sock. With this method the sword looks a little bit more realistic and used.

Be careful with how much black paint you use in this mixture. I'm used to use much more water than paint. And then adding more black paint if needed. With this you avoid ruin your paintjob. Better safe than sorry.

Wrapping the handle in textile tape

Here I wrapped the handle with textile tape.

I recommend doing this step AFTER painting the sword - unlike me.

With this Trunks sord is nearly done. The last step is varnishing the sword.

Varnishing the sword

With the final step I varnished my sword with some clear and glossy spray varnish.

Results

With this Trunks sword is finally done! 🥳🥳🥳