Rex - Harpoon Bracer Tutorial

Hello! This tutorial will show how to Rex’s harpoon bracer that he wears on his left arm!
Rex is the protagonist of the video game called Xenoblade Chronicles 2 on Nintendo Switch.
Here is an overview of what needs to be done:
First, let’s focus on building the pattern for the base of the bracer. The base looks like a barrel with its convex shape at its middle, so we will need to reproduce this shape in our patterns.
I have made various experiments with the the patterns where I am cutting the width at the top and bottom extremities of the pattern to create the subtle convex effect at the middle of the bracer. I have used the leftmost pattern in the next picture, which I will repeat multiple times until I get the desired “barrel”.
As you can see in the next image, I have duplicated the chosen pattern above multiple times and united them all at the middle. Feel free to test it on your arm by taping the side of all openings together.
Once you are satisfied, it is time to transfer the pattern on 10 mm EVA foam.
This is what you should have after transferring the pattern on EVA foam. Then, carefully remove the excess foam using a sharp knife. Make sure you cut on the inside of the pencil/marker marks so that they are not visible on the cut piece. Also make sure that your cuts are as vertical as possible.
This is what you should have after the cut. Make sure all sides of the foam piece are clean and without bumps: use a rotating tool (Dremel) with a sanding head to smooth all sides if necessary.
Then, it is time to unite all openings you have made. Using a strong glue such as Barge contact cement, carefully glue the sides of all openings together. You should have a nice barrel shape with thinner upper and lower extremities.
There might be small openings where the glue was applied at the surface of the foam piece. You can fill them and make them disappear with either Kwik Seal or foam clay. I have decided to use foam clay on my side. When the foam clay has dried after 48 hours, you can sand the excess at the surface with a Dremel and/or sanding paper to make the surface smooth without any bumps.
To close the foam piece (and form the barrel), you can use a very strong glue such as Barge contact cement to unite both foam piece extremities.
Once it’s all done, the next step is to make the 3 golden bands at the extremities and at the middle of the bracer. There is a 45 degrees angled bump at the middle of each golden band. Therefore, we will need to create bevels on the foam pieces we need. After cutting the foam pieces (see the next picture), you can make a oblique cut with a sharp piece at 45 degrees, which will form a foam strip. Unite both of these strips to form a nice golden band.
If you have removed too much foam with your cuts, you can always repair your piece or fill some gaps by applying foam clay and sanding after (see the last picture of the montage in the next picture for an example).
If you are looking for good references on how to make bevels, Punished Props Academy on YouTube has a very instructive video on how to realize them. Search for “punished props bevel” and you will find it!
Then, let’s glue the band at the middle of the bracer. You should use a strong glue like Barge contact cement for this.
You will need to create 2 other golden bands, using the exact materials and techniques you have used for the 1st golden band. They will be situated at the top and bottom extremities of the bracer.
After that, you deserve some congratulations! You have done the base of the bracer!
The next major thing you have to build is the harpoon platform and gun on the top of the bracer. This piece is very detailed and will deserve a lot of attention. So, let’s start by creating a top-down pattern detailed every bump, detail and piece you need to do. See the next photo for all these details:
Following this pattern, here is a front view of the harpoon module showing its desired height. It is about 3 cm high (so, a stack of 3 times some 10 mm EVA foam!)
Once the patterns are made, it is time to start transferring the first pattern on 10 mm EVA foam (the base of the harpoon module).
There are some angled portions on the side of the harpoon module, which look like triangular prisms with a right angle. To create those, let’s get inspired by the other bevels we have already made for the golden bands of the bracers.
First, let’s determine the width of each angled portion, then cut the necessary pieces into 10 mm EVA foam. Then, let’s carefully (and slowly if necessary) cut away the foam following an oblique line from top left corner to bottom right corner. A hot knife could make this easier. At some point, it might be difficult to cut away the foam, so you can switch to a Dremel with a sanding head to remove the foam.
The next photo shows how it looks like when one of the angled sides is glued to the piece.
You might have noticed that some other parts have been added:
  • the middle piece at the back of the harpoon module: it is just a 10 mm EVA foam rectangle glued to the base;
  • 2 squared sections that are lowered halfway at the middle of the harpoon module. To achieve this, I have cut the 2 squares away from the base, then I used a knife and a Dremel to remove half of the squares’s height. Finally, I have glued the resulting squares back to where they were, but on the lower height half of the base.
The next image shows all the angled and central portions added to the harpoon module. I have also added 4 small foam bands (2 per square) at the middle of the module. These are the gray bands from the reference picture. They are built using 2 mm EVA foam.
There are also gray bumps at the middle of the harpoon module. They are for the pyramid-like bumps at each place where a bracer’s golden band goes under the harpoon module. You will need 3 pairs of these (front, middle, back). I have used foam clay to build them.
Once the foam clay is installed and dried for these bumps, you can use a Dremel to create the pyramidal edge at their middle. In the next photo, circled in green are bumps that have received the Dremel treatment. Circled in yellow are bumps awaiting some Dremel love!
You might have noticed a new module present on the image, the one holding the harpoon arrow itself (which I call the shooting module). It’s all built using 10 mm EVA foam (for the base) and 5 mm EVA foam (for the side rectangular prisms and the layer with the 2 U shapes. There are 2 circles made of 2 mm EVA foam on the side and front of the shooting module.
So, at this point, most of the harpoon module components should be done (except the arrow and the underside of the piece, on which will come back later).
Now, let’s come back on the barrel base of the bracer. Since it will be on your arm, you might get bumped during cosplay events and your bracer could get hit, especially in a merchant hall, it might be a good idea to cover it with something strong and durable like Worbla. This is what I have decided to do, so you want to follow this path: let’s work on covering the barrel base with it.
First, we will need a cut a worbla piece that is big enough to cover the whole barrel. As shown in the next photo, allow 2-3 inches on each side to cover the entire barrel, including a bit of the inside.
Then, using a heat gun, heat the worbla and carefully put it on the barrel base. Make sure to use a pointy tool (like sculpting ones) to make sure the worbla goes in every crack and that no details and cracks are lost. This step takes some time, so get ready!
Then, you should have the barrel base fully covered with worbla like the next picture. It is ok if there are some bumps and worbla buildups at some locations: you can remove them by heating the worbla again, using a pin to remove air bubbles and sanding the excess. There are plenty of resources online that can help you with using worbla! Don’t hesitate to use them!
Since there are vertical lines on the barrel base, I have decided to use a sculpting tool to push the worbla where they are and create these lines. You can see it in the next picture. You can also notice the sanding I have done with the Dremel to make the worbla smooth and uniform!
Here is one particularity for the barrel bracer I have done: unlike what I recommended previously for closing the barrel (which I still recommend), I have closed the barrel using worbla. Here is how I did it (next picture, left). However, this is not very beautiful as I could not close the extremities: you can see the openings that are still there at the top and bottom.
To hide this, I have decided to cleverly install the harpoon on top of where the closure has been done. Like Adam Savage, famous prop maker, has said before: “Hide your crimes!”
The convex shape of the barrel poses a problem, however: there is quite a gap between the ends of the barrel base and harpoon base. To hide it, let’s build some padding to the bottom of the harpoon base, which has the advantage of hiding the gap and being realistic at the same time, since it gives the impression of solidifying the harpoon base for powerful shots!
With the golden bands now final (now covered with worbla), we can then know where they will hit the underside of the harpoon base. We can then build openings for the golden bands.
For the middle opening, I have removed 5 mm of EVA foam on the harpoon base piece (with a 45 degrees angled cut).
For the top and bottom openings, because of the convex shape and the important gap, I have added a 10mm EVA foam rectangle on each end and I have built an opening using foam clay.
Then, you can sand all of this with a Dremel later to have a nice finish.
Now, let’s finish the visible parts of the harpoon module. We will now build the harpoon arrow and make it hold on this module on the top of the module. Here is a nice picture of it for now (in case you have missed the details when it was mentioned before):
To create the base of the arrow, remember what you have done to create the golden bands? It’s exactly the same thing you have to 2, except that you will glue 2 pieces together! It’s always fun and easier to reuse the same things and techniques on different parts of the piece!
And now, let’s work on the fun part: the arrow end! Here is a reference pattern of all the pieces you have to build.
The key to achieve this complex construction to do it step by step, portion per portion, one piece at a time. First, let’s work on the tip of the arrow! You can cut this part from the pattern you have built before and transfer it on 10 mm EVA foam. Then, using a sharp knife, you can remove half of the foam using an angled cut. You can finish the job with a Dremel to create a smooth result without bumps.
Then, it is time to do each part of the arrow. You can divide each branch into sections that you can do independently of each other.
You can create one long foam piece just like the diamond one for the base of the arrow, then cut it into small pieces, one for each section. Then, using a sharp knife, you can create angled cavities for 2 sections to be glued together: the key is to make sure that you have a contiguous top middle edge for each branch of the arrow. Here’s an example for all of this in the next picture:
As the width of each branch goes smaller and smaller when getting closer to its pointy end, you will need to make angled cuts, with some Dremel work, to keep the top edge visible and the surfaces smooth:
Then, once you are done, you can fill all the small gaps between the sections, on both sides of the arrow, with foam clay.
(If you have to privilege one side of the arrow over another, I recommend the top one as the bottom one will not be that much visible.)
Now that are done with the arrow, let’s build the iron sights for the harpoon that will wrap the base of the arrow. You can build it using small strips of 5 mm EVA foam pieces (see the next picture). The entire piece will need to be covered with worbla.
You will also need to cover the arrow with worbla. To achieve this, you can cut very small strips of worbla and, using a heat gun, carefully cover the entire arrow with them. Don’t worry about the worbla excess on top of one another: you can sand it later with a dremel.
This is how the arrow looks like when it is entirely sanded with a dremel. With it, you can make sure that all edges are sharp and that you don’t lose any sharp detail that was in the foam.
Now, let’s move to another (but subtle) piece of the harpoon module: the one holding the metallic wire bound to the base of the harpoon arrow! To build it, I have decided to reuse an underthread bobbin that was empty of any thread as the base, with side pieces made of 5 mm EVA foam. For the metallic wire, I have found a hook wire kit bought at a Wal-Mart to be useful and exactly what I needed!
For this piece, it is the exactly the same as the others of the harpoon module: let’s cover it with worbla! (except the bobbin, which I did not cover).
Finally, we have to cover the whole harpoon module with worbla. Let’s cut ourselves a big enough worbla piece (at least 3-4 inches all around the module).
And then, using a heat gun and sculpting tools to push the worbla in all cracks and holes to not lose any detail, let’s apply the worbla everywhere on the harpoon module! You will need to take your time for this!
If the worbla cracks or breaks or there is simply not enough worbla to cover all holes, do not hesitate to add small worbla strips where it’s needed, heat them and apply them. You can always sand after to remove traces of these fixes.
Once all pieces of the bracer (barrel base, harpoon module) are covered with worbla and sanded to remove any bumps and have smooth and uniform surfaces anywhere, it is time to prime and paint all pieces!
For priming the worbla, I am using multiple layers of Super Heavy Gesso from Liquitex. The technique to follow is this:
  • apply one layer of gesso (using a brush) and let it dry;
  • sand the gesso (start with a rough grain) with sandpaper to have a surface as smooth as possible;
  • repeat until you have a very smooth surface:
    • use water to distribute the gesso (with gentle brush strokes) for the next layers - this will make the gesso smoother;
    • after sanding, if there are small holes or an irregular surface, you can always add Speed Dry cement from Lepage to fill them. You can sand the excess after.
    • as you advance in the iterations, use smoother and smoother grain for the sandpaper;
I heavily recommend using the tool in the middle image above for sanding your big pieces, it is very efficient and allows you to use all your physical strength for sanding! For cracks or small / hard to reach places to sand after applying gesso, you can glue sanding paper to the end of a wooden stick (right picture on the above photo): Gorilla Glue gel works well for this!
To make sure that the gesso is smooth on your piece, you can light it up close to a light source and use the reflection to evaluate the smoothness, like I have done in the next photo:
At the end, if you are following all these steps, you should have a very smooth and beautiful piece:
Then, it’s painting time! The next picture shows the various steps that you should follow. I am using the following colors and applying them with brushes:
  • Blue: from Pebeo, code 14 - Opaque Cobalt Blue Hue
  • Yellow Ocre (base for Gold): from Pebeo, code 27 - Yellow Ochre
  • Gold: from Pebeo, 50% of code 352 - Iridescent Gold and 50% of code 351 - Iridescent Silver
  • Black (for shading and highlighting): from Pebeo, code 26 - Mars Black, applied with water to dilute and spread the paint.
You may note that I have darkened the inside of the golden bands around the wrist and close to the elbow to simulate some shading.
There is one more thing that you could do for the barrel base: if it is stable of your arm and around your wrists, you could glue squishy foam at the extremities on the inside. It will prevent the barrel base from moving freely on your arm!
Now that the barrel base is primed and painted, let’s do the same thing on the harpoon module!
The surfaces to apply gesso on are smaller and could be harder to reach. You can use smaller brushes to help you. Using wooden sticks with sanding paper glued at their tip will be very helpful. The next photo shows you the smooth result you should have at the end when it is over.
Now to the painting! For the arrow (see next picture), I have decided to use a gray base (left). It is composed of a dark gray paint, on which I have mixed a bit of white paint (middle photo). On top of this layer, I have added metallic paint (right), which gives a shiny look to the arrow.
You can also highlight the angles and edges of the arrow by adding a little of white paint there, which makes the arrow stand out a bit more.
For the harpoon module, it’s mostly gold except in 2 places:
  • on the topmost part of the module. There is a red dot at the base of the arrow and a bright yellow portion at the back of this portion (see in the right section of the next photo).
  • at the middle of the harpoon module where the 4 small bands need to be painted silver (same colors and technique as the harpoon arrow). It is unfortunately not shown in the next picture.
The gold paint application follows the same steps as the golden bands of the barrel base: yellow ocre as the base, with a mix of 50% metallic gold and 50% metallic silver on top.
You will also need to prime and paint the wire module at the top back of the harpoon module and the iron sights.
Finally, you can highlight the edges, bumps, cracks and holes by adding a bit of black paint there. You can also mix yellow ocre and black paint together to create a dark color that is between yellow and black for this shading / highlighting job.
About holding the wire module in place, you can use a very strong glue like Barge contact cement to bind half of the bottom surface to the harpoon base. This could be a fragile part, so make sure you apply enough contact cement. You could even build a triangular base to extend the harpoon module to cover the entire bottom surface of the wire module.
For the wire itself, I have just rolled it around the bobbin at the center of the wire module. I have spread white liquid glue (the one who might have used at school when you were young) on the wire to “freeze” it in place.
Bonus points for making the wire enter into the topmost part of the harpoon module: I have used the drilling head of my Dremel to create a hole and glue the wire end inside.
Oh, and don’t forget to coat and protect the entire paint job you have done with 2-3 layers of Mod Podge!
Now, let’s work on attaching the harpoon module to the barrel base. There are multiple ways to achieve this. For travel and packing purposes, you might want to be able to detach the harpoon module and keep it separate from the barrel base. This is what I attempted first with magnets. Unfortunately, it did not work for me and there was still a significant gap between the 2 pieces. So, I had to find another solution.
I have decided to permanently bind the harpoon module and the barrel base. I also used this opportunity to hide the 2 openings at the top and bottom of the barrel base that I could not remove! And to remove the gap, I have decided to remove a portion of the barrel’s surface to form a stable, even and uniform base on which I could attach the harpoon base.
As you can see in the next picture, I used my dremel to sand a good chunk of the middle and I added 3 EVA foam strips that will be glued in the 3 underside cavities of the harpoon module.
You can then paint these 3 EVA foam strips since they will be visible a little bit from some angles (see the next picture). Finally, you need to use A LOT of Barge contact cement to permanently glue the harpoon module to the barrel base.
Then, I believe you are done with Rex’s harpoon bracer! You should contemplate and reflect on the hard work you have done with a nice picture of your work!
Here is how it looks for me on the entire cosplay! Big thanks to MrJechgo for the picture!


Congratulations! You now know how to make Rex’s harpoon bracer! You should be proud!
If you are interested with the other parts of Rex, check out my other tutorials on my cosplay page GDICommander! Leave a like and follow my page to not miss any updates!
If you have any questions, comments or suggestions about this tutorial, let me know in the Comments section and I will address them!