Kingdom Hearts - Kingdom Key Keyblade




Introduction: Kingdom Hearts - Kingdom Key Keyblade

About: Currently in Highschool. When not doing school, I fill my spare time with (in order of importance) making stuff, wood turning, cooking, or playing video games.

Making props for cosplay or just because can be loads of fun.

In this Instructable, I will show you how to make a the Kingdom Key from the popular Playstation Game Kingdom Hearts.

I personally love to make things and also love video games. These two things have culminated in the me creating a Keyblade.
The methods I am using can be used for making other props and pieces of cosplay as well. It is relatively easy to do, and is also rather inexpensive.

If at any point you are confused, feel free to message me. I would be happy to clarify or help in anyway.

Here is the basic method to make this. This Instructable goes more in depth for each step, breaking it down, and what not.
1. Draw it.
2. Cut it out.
3. Spackle
4. Prime
5. Bondo
6. Paint
7. Varnish
8. Final assembly.

COST: ~$45
TIME: ~7 Days


Rigid Foam Insulation $6 - The link is not actually what I got, but it is basically the same thing. I got 1in x 2ft x 2ft. If you cannot find that, you can always get the 1/2in and double it up. It is in the Building Materials section.

1" PVC Class 200 $1 - They sell it in 10ft pieces, but you only need about 4ft. When you are going to buy it, MAKE SURE THE 3/4" PVC WILL FIT INSIDE. If not you will have to sand down the pipe to fit them together.

3/4" PVC $1 - This is sold in 2ft pieces, get the 2ft pieces

Liquid Nail : Projects $4

Spackle $5 - I already had Spackle, so what I suggest is get the Spackle with the fastest dry time, speeds stuff up quite a bit.)

Various Sandpaper Grits $10

Gesso $8 - Or any foam safe primer. If not, the foam will melt. I didn't use a foam safe primer, I used Kilz. It melted the foam, but it is not that big of a problem if enough Spackle is used

Bondo $11 - This is in the paint section. It is used to fill cracks in automotives, but we are using it to harden and protect the foam. It prevents the foam from snapping in the future. Before you buy this, pull off the white cap and check to make sure there is a tube labeled cream hardener. The hardener is very important.

Disposable Gloves $2

Paint $8- For this, you need Black, Gold, Silver, and Blue. I got Metallic Silver spray paint and a Golden Yellow. I decided to use Acrylic paint for the blue and black since it was only a little bit needed

Varnish $7 - I got Miniwax Polyurethane clear gloss, though depending on what other project you are doing, you may want semi-gloss or satin finish


Saws - Jig and straight
razor blade - Needs to be sharp. Can be taken from a box cutter.
Measuring devices- Yard Stick/Measuring Tape, Ruler
Square/Triangle/90 degree angle
Plastic Spatula (to mix the Bondo)
Popsicle Sticks ( for spreading the Spackle and Bondo)

There are other methods of cutting the foam (such as hot knives and electric wires) and they would work just as well as a razor.

Step 1: Making a Drawing of the Keyblade

The first step in this endeavor is to create a stencil of what the keyblade should be. I have created a Google Sketch Up of what the dimensions for everything should be. I actually took paper and taped it together to make a to scale drawing of the Keyblade to get proper dimensions. You don't have to do that, you can probably get away with just drawing the handle and the key.

Then you can use the Google Sketch Up (free for everyone) to plot the the points. I marked various points on the edge the square that when plotted against other points on the adjacent side give the positions of vertices and points. Each point is measured from the nearest corner, except for one side of the Key portion which is measured from the top of the keys box. You can use the tape measure tool in Sketch Up to measure other points if you need to.

I noticed that a handle that fits in a 9in x 9in box is a bit too small. Both hands might not be able to grab hold of the Keyblade once complete. Consider increasing measurements by 10% or so that is better fits you. 

To stencil out the handle, first draw out a 9in x 9in box (this is bigger than standard paper). Then plot all the points. Then connect the dots. 

To stencil out the Key, draw a 7in x 5" box. Then plot all the points. (The shaft is not part of this box). Then connect the dots. 

Quick notes, a small amount of knowledge regarding Geometry is required to to do this. It is not complicated stuff, but just kinda logical things like proofs and knowing that if the edge of the circle is touching a certain point, then then the distance from that point to the center is the radius. 
Also, some of the plotted points may not meet up exactly, but they should be very close. 

Step 2: Cutting Out the Handle

Now that you have a stencil made for the Keyblade, it is time to cut it out and tape it to the foam. 

Cut out each square, and tape it to the foam. You can then use your preferred cutting tool to outline the piece you are cutting. I would recommend to use the saw to do rough cut. The saws tend to shred the foam a little bit, and not give it a smooth cut. So be sure to leave about half an inch away from the edge so you can go back and give it a proper cut. 

This was the first time I have ever done this, so through trial and error I figured it out. The most important thing is to make sure you cut straight and clean. The worst thing is when you cut too far in and have to restart. Minor defects are OK, Spackling can fix it. 

So rough cut the out side, then follow with a close cut with the razor. (Cut off small pieces at a time to ensure you are not cutting of to much at a time)
To get the inside, I punched out a little hole, stuck the saw in, and then sawed out as much foam as I was comfortable with. 
Once everything is cut out, sand it with your lowest grit and work up to higher grits (I went 60, 120, 220). 

Step 3: Cutting Out the Key

Cutting out the Key follows the same method as cutting out the handle. You might have noticed that I cut out the shaft of the blade as well as the key portion for this. This is because I was not sure how I would connect the key to the shaft, and I wanted to leave a little extra foam on in case I chose to make a nub to attach it. I ended up not doing that. None the less, leave maybe 1/8" on that can be sanded down to make a curve late to match the pipe. 

 For the harder to reach areas, I recommend getting close as close as possible, and then doing the rest with a folded up piece of course sandpaper. 

Cut out the key. Tape it to the foam. Rough cut. Close up cut. Then finish with sandpaper. 

Be sure to look at it from both sides so you can catch any faults in it. 

Step 4: Cutting the Bumps for the Handle

On the handle of the Keyblade, there are two bumps where the shaft intersects it. To make these bumps, cut out blocks that have the same length and width of the bump. Then taped them down onto the area where the bumps would be. 
Orient the handle so that it is flat and so that the flat side with the bumps is facing you. Locate the center of the this rectangular area. To create the the bumps properly, take a compass and place it at the center point and open it so that it meets the edge of the flat side. Now rotate it so that you have made markings on the two blocks that you have placed on either side of the handle. 

You should have arcs on both blocks. Remove the blocks from the handle and carve out the curved shape. Once you have cut it to the proper size, take the Liquid nail and apply it to the bottom of the curved block. Place it on the handle and then tape it down to help it stay in place.  Once it is in place and secured, sand it down a little. 

Don't worry if the shape is not perfect or the pieces don't match up. Spackle will help shape. 

Use this same method for the rest of the bumps. 

Step 5: Spackle and More Sanding

So currently, you should have the handle cut out with the bumps attached and the key cut out. 
Now we begin fixing it up a little. Take your Spackle and begin applying it to areas that have holes or are not smooth enough. 

IF YOU ARE NOT USING A FOAM SAFE PRIMER, COVER AS MUCH OF THE FOAM AS POSSIBLE. Specifically the sides and areas where you can see the bubbly texture of the foam. It is these areas that will melt if you use a non foam safe primer or sealant or anything else. 

Apply one layer of Spackle. Get in all the holes. Build up areas that you cut to far into. Also get into areas where the pieces of foam are meeting, this will help create a nice smooth transition.  Try and make everything as smooth as possible.  Let it dry. When one is drying, work on the other one. 

Once they are dry, sand them down with 120 for the slightly rougher areas and 220 to make it smooth. If it smears instead of becoming dust, it is not dry yet.

After you sand, you will still have some spots that may need more Spackle. Just keep applying and sanding. Try and make nice sharp edges and smooth curves. 

Step 6: Cutting the PVC to Length

You should have two different diameter PVC pipes. 1" and 3/4". 
If you got the 2ft piece of 3/4" PVC, you don't have to worry about cutting it at all. It is already the proper size. However, if you cannot fit the 3/4" in the 1", then you will need to somehow file down the outiside of the 3/4" to fit inside. 
You also want to take a knife with a handle and sharpen one end of the 3/4". This is going to help make the hole that the shaft will go in. Use some of the left over foam to test the sharpness. It should make a a nice plug out of the foam and not tear it up. 

For the 1" foam, you will need the cut the 10ft piece down to about 28". Depending on what you use to cut it, you will also need to sand down that edge to make it nice.  Take part of the REMAINING 1" PVC and sharpen the end like you did with the 3/4". This is going to help cut out the plug that will go in at the end of it. 

Step 7: Putting a Hole in the Handle.

You should be able to take the sharpened 3/4" PVC and drive it through the handle to create the hole that it will go through. Find the center of that area, then position the pipe accordingly. As you drive it through, reinforce the area where the pipe will come out with you hand to prevent it from tearing out. 

If you the bumps pop off lift up, do not worry. You can still glue them back down. 

Do them one at a time. After you do the first one, and go all the way through, remove the pipe. You will notice the it is a very tight fit for the pipe in the hole. Take some 60 grit to it and open the hole up a bit. You don't want it too big, or you will have a gap later when you are gluing it up. Once the pipe can easily slide you should be fine. 

Remove the foam from inside the pipe, and reinsert the pipe through the hole going toward the base of the handle. Drive it into the base but do not go all the way through. Go about half way. Remove the pipe. You will not have a plug that will come out with the pipe. You will need to take a knife to shred up the area inside the circle the pipe made. Then sand that area down. 

Once both holes are made, remove the pipe and glue down anything that came undone. 

Then once the glue is done drying, re-spackle it to make it look nice again.
In the next step, we will fill in the areas that the pipe will not be in so there is no gap. 

Step 8: Filling in the Extra Space Where Pipe Goes.

To fill in the areas that the PVC pipe won't be, take two pieces of paper and tape it around the PVC. Reinsert the PVC into the handle, and position the paper so that one is in the bottom and sticking out, and the other one should be at the top with paper sticking out on both sides. 

Now, take Spackle and fill in all the areas that have holes. Fill it in right up to the paper. When you are done, you can remove the PVC, but DON'T REMOVE THE PAPER. 
When the Spackle is completely dry all the way through, you should be able to fold the paper away from the foam and remove it with out breaking away too much Spackle. 

Now you can sand it down to make it look nice. 

Step 9: Fitting the Key to the Shaft

Now we will attach the Key to the shaft. As you know, the shaft is round, so we will need to match this curve with the form. 

If you still have too much excess foam on the key, trim it down to 1/8" more than needed. 

To start, take the most coarse sand paper you have and make a valley in the bottom side of the key. Once a decent sized valley is made, take the sand paper, wrap it around the 1" PVC, and then rub the key up and down the sandpaper. This will make the curve in the foam match the curve of the PVC. 

Once the curve is matched to your liking, apply the Liquid Nail to the foam, and stick it on the pipe. Make the end of the pipe and the end of the key meet up. Then what you can do is apply tape to both sides so that it stays in place. You can then take some of the scraps of foam and place them under the key so that is stays straight and not curved.

Once the glue is dried, trim off the excess. Apply some Spackle to fill up the gaps. Sand. 

By the end of this step, you should be able to assemble the Keyblade almost completely, only having to use tape to hold the 3/4" to to the 1" PVC. 

Step 10: Making the Slant at the End of the Blade.

At the end of the blade, on the bottom half of the pipe, there is a slant. 

Make a mark that is half way down the pipe from the key on both sides. 
The make a mark that is directly below the key on the bottom side of the pipe. Then make a 1/2" line from that point running along the length of the pipe. Now connect the end of the 1/2" line to the two marks you made halfway down the pipe. When viewed from the side, you should see a triangular shape.

Place the pipe in a vice and cut the pipe so that a nice slant is created. Use a file or sandpaper to bring it down to the proper shape and so that it is even. 

Once the slant is made, we need to plug the end of the pipe. Remember that piece of 1" PVC that we sharpened? Well go ahead and stick it in the foam and get a nice little plug. To remove the plug from the PVC, take some that fits in the PVC and pop out the foam. 

Coat the plug  in the Liquid Nail, and insert it into the key. Let it sit for a while before you start cutting it up. Once it is dry or doesn't move any more, go ahead and trim the foam to match the slant and edge of the PVC. Sand. Spackle. Sand. Spackle. (Make sure you Spackle if the primer is not foam safe. 

Step 11: Fitting the 3/4" Into the 1"

When the 3/4" goes into the 1", there is quite a bit of room. To make the 3/4" fit in, we will make some duct tape spacers.

First, take the 3/4" and insert it in the handle. Make markings where it meets the foam of the handle. The 1" pipe should be 2" from the edge of the foam. Make that marking as well. 

Take you ductape, and make around ~4 wraps around the end of the 3/4". Add or remove tape as needed so that you get a nice fit that is not too tight, but also not so loose that the key still rotates freely. Once the one on the end is in place, make another ~4 wrappings about 1/2" from the marking on the 3/4" that represents where the edge of the 1" is. (I know that may be confusing. Refer to the pics to help you understand)

Step 12: Priming.

If you have the Key blade assembled, go ahead and disassemble it. You should have 3 pieces. The Key with shaft, the Handle, and the handles PVC (the 3/4").


Priming is relatively straight forward. Do them one at a time and let them dry. Try to avoid applying too much primer and having it bead up. You can do some fine sanding once it us dry.

Step 13: Bondo (Somewhat Optional)

Bondo is automotive filler. We are using it to strengthen the foam. After applying it, the foam become hard as rock. Prior to Bondo, the foam would snap with relative ease. With the Bondo, you could hit someone up the head with the Keyblade and they will be hurtin.
That being said. Applying the Bondo and cleaning it up is fairly difficult. If you plan to actively use your prop for Cosplay or other things, I recommend Bondo-ing it. If you plan to make it and place it on the wall, you can probably skip the Bondo.

If you have not bought the Bondo yet, make sure when you buy it has the Hardener Cream.

Bondo is high in fumes, so make sure the area is well ventilated.

You will need a smooth, non-porous surface to mix the Bondo, gloves, spatula to mix, and Popsicle sticks to apply.

Reading the direction on the Bondo will tell you how to mix it, but I will hit some important points here.

Take a smooth, clean, non-porous surface to mix the Bondo on.
They say to do 3" diameter by 1/2" tall of filler, and then about 2" of hardener. This stuff hardens in about 4-5 minutes. It is very unlikely that you will finish all of if in that time. I recommend mixing less than that so that you do not waste.
Apply onto the foam using the Popsicle sticks. Try to make it as smooth as possible.
When you run out of mixed Bondo, or it hardens up, set the foam to the side to dry. Mix up some more Bondo, and to the other piece of foam.

After about 20 min, the Bondo is sand-able. So remove the big bumps and make it relatively smooth with 60 grit. Layer more on if needed. Make sure all of the foam is covered with Bondo. Repeat process as necessary.

When you are done layering on Bondo, you will have to sand it down. It will take a while and you will go through quite a bit of sand paper. Guaranteed, you will still have some holes or areas that missed a layer of Bondo. After sanding it to the best of my ability, I went ahead and used more Spackle to fill in the holes. Let the Spackle dry and sand it smooth.

Now we are ready to Paint.

Step 14: Painting Time.

We are nearing the end of the project. By the end of this step, we will be able to really see the keyblade. 

The 3/4" pipe is going to be painted two different colors by hand. The Key and the Handle will be solid colors. The key will be metallic silver, and the handle will be a golden/yellow color. 

To paint the key, I grabbed another piece of PVC that fit inside the Key. I wrapped it with duct tape to make it fit better. Now i can hold the smaller PVC and paint and rotate the Key. This also helped me position it to dry. 

To paint the handle, i took the end of the 3/4" that goes into the 1" and inserted it into the handle. So now I have something to hold so I can paint the handle. It also helped positioning the piece to dry. 

Shake up the cans, and spray. Keep a decent distance from the piece. Keep moving the can to get a proper coat. You do not want to put to much paint on it or the paint will bead up and run down it. 

I applied 3-4 coats of paint to help ensure I got proper coverage. 

To do the pipe of the handle, I used acryllic paint.  I painted the area that you hold black, and the  other area blue. Layered a few times to give it a rich color.  Really simple.

Let the paint dry COMPLETELY before you start messing with it. If it is not COMPLETELY dry, you will smudge the paint, tear the paint, or get finger prints on it. They you will have to apply another coat of paint. I had to do that several times. 

Step 15: Varnish

Varnish the areas that need varnish. The handle already has a clear gloss on it, and the paint I used on the key did not recommend applying a clear coat on it, so I left those be.

The black and blue handle needs a coating to protect the acrylic. If you used other paints on Key and Handle, you might have to varnish them as well. 

Using a foam brush, apply the varnish and let it dry completely. 

While you wait for the varnish to dry, you may want to sand the holes in the Handle. The varnish adds a little thickness to the pipe, which may cause the pipe to not fit in the Handle. If you try to force it in, you will damage the paint. 

Step 16: Making the Silver Dots on the Handle

I nearly forgot about this step. Luckily, I remembered and figured out how to do it. 

To put the silver dots on, you could either cover the entire handle except for the spots that need to be silver and then spray, OR you could spray some paper silver, cut out some nice circles, and glue then down. Either way would work. I choose to do the paper method. However, if you happen to have a silver paint that matches the key, you could use that instead.

Paint the paper and let it dry. Flip the paper over, and draw 4 circles that are the size you want. Cut them out to the best of your ability. Apply a small amount of glue to the unpainted side. Then place the silver circle on the handle at the location you want it.

Step 17: Glue

If you made it this far, kudos, you are at the last step. 

Take the Liquid Nail and apply it to the area between the two pieces  of duct tape, as well as a little on the duct tape. Mound up the glue so that both PVC pipes are connected by the glue. Once inserted in, you can also fill in the remaining hole with more glue, then use paper towels to clean it up. 

Then apply glue to the bottom hole of the handle. Insert the pipe all the way through to it. Once in, go to the top one and put a little squirt to help fill in the area that are not touching the pipe. I used a tooth pick to help better distribute it. You can take a paper towel to wipe away any excess.

If you apply glue to the top hole first, when you insert the pipe, the glue will smear all over the pipe. So put glue in at the bottom first, insert the pipe, and then glue the top to fill in the remaining holes.

Make sure before you leave the glue to dry that the key is lined up with the handle. Once the glue dries, there will be no adjust it.  

Give it 6 hours to dry. 

Step 18: Admire and Enjoy.

Step back and admire your new Keyblade (or other prop). 
Then come back here and say you made it. Post pictures and stuff.  
Then go relax. You deserve it. 

Alternatively, if you just scanned through this to see what the steps are to assess your own ability to follow this Instructable, go for it!
If you ever need help, message me. I would love to help. 

Game.Life 4 Contest

Participated in the
Game.Life 4 Contest

Be the First to Share


    • Baking Contest

      Baking Contest
    • Clocks Contest

      Clocks Contest
    • Game Design: Student Design Challenge

      Game Design: Student Design Challenge



    8 years ago

    Nice! Straightforward and pretty easy, too :)! Love this series so much