Introduction: Ghosts in a Shell Bouncing Ball (Glow in the Dark)

About: My name is Rutger Oomkes and iI am a silicone jewelry designer. Further i worked at the creative care lab Waag in Amsterdam My true passion is creating functional art. At this moment my favorite materials are …

In this instructable I will show how you can create your own silicone figures with molding. For this contest i decided to make a glow in the dark ghost bouncing ball. I have made other bouncing balls like a goldfish in a bowl. But the techniques i show can be used i many different varieties with silicone as the end result. Most video's and instructions use silicone as a mean to create other things. Silicone is also very cool as a end result. It has many good applications because it is water proof, flexible, temperature resistant and very light weight.

I decided to make a bouncing ball with glow in the dark ghost. To make something untouchable and out of this world something you can actually play with. It was a nice side project which i loved spending a long weekend on. I made this design at home without the use of some handy tools to improve the design.

Step 1: The Materials

- Glue gun (for creating the mold)

-styropor foam (for creating the mold)

-Silicone addition ( A + B components)

-silicone transparent (A + B components)

-measuring cup

- injection needle (for the adding of silicone additon B)

-Apoxy clay (for molding the figure)

-silicone mat (to place the molded figure on)

-glow in the dark pigment (blue and green)

-Black pigment

-weight scale for measuring the amount of glow in the dark pigment

-White vaseline


-plastic hollow ball (the ball has to connect well


-straw (to rmove the bubles

Step 2: Making the Figure

To create the ghost i used apoxy clay. A nice material consisting two components which hardens when you mix them together. Make two balls of the same size and mix them together till you only see one color left. Then the apoxy clay is ready to use for creating your figure. At first it is very soft and good to create shapes, after about a hour it slowly becomes harder and then you can work on details. You have around one and a half hour to mold it before it becomes to hard to work with. I wanted to create the idea of a ghost without going to much in detail. Some simple shapes that people can recognize a being a ghost.

To measure how big I had to make this ghost i used the plastic hollow ball. I wanted three ghost in the shell so i checked how this would fit. The ball has also the purpose of getting the bend right for the figure. I use a silicone mat to mold the figure on, so that after the figure is hardened it is easy to remove. When molding the ghost i had i mind how i was going to making a mold out of it. This is a fun project and i wanted to create a single mold to safe time. Because of that reason I made one side flat so it would be good for a single mold. When creating a design keep in mind how the mold should be.When you decide to make more complicated designs I advice using at least a two sided mold.

Step 3: Giving the Ghost Character

In the previous step i made a simple figure without eyes and mouth. I could have added those already in the molding. I decided to wait till it hardened, i first want the outline to look nice. Using a little drill I created the holes for the mouth and the eyes.

Step 4: Making the Mold

As a base you need a stable smooth surface. I used for this plexiglas. I outlined the figure with a rectangle. Make sure the figure do not cross or touch the outline. I made a rectangle so place the walls would be more easy. After that I removed the figure. With a knife i cut 4 styropor pieces to make the wall. You can use different kind of material as long it is waterproof. i placed them together and with a glue gun i connect the walls to each other and to the plexiglas. Also cover the inside edges and corners to make the mold waterproof. For this reason I removed the figure so I have the space to reach all places. Then i place the figure back and with a bit of glue to make sure it will stay in place.

Step 5: Pouring the Silicone in the Mold

To calculate how much silicone you need i use the measuring cup and fill with some sort of rice (can be grains, water, etc) and pour into the mall. Calculate how much rice you need to cover the mold and then you see approximately how much silicone you have to use. I ad a small amount on top since silicone gets into the smallest holes. This saves the cost of using to much silicone.

Pour the right amount of silicone addition A in the measuring cup. Add Component B to it and stir the mixture well. The ratio for this silicone is 10:1, this may vary on the type of silicone. Using a straw I removed most of the bubbles before i started pouring. At home i do not have a vacuum chamber to get rid of the bubbles. For this project this worked well enough. When it ready pour in the mold and let it harden.

Step 6: Removing the Figure From the Mold

With a hobby knife i remove the walls. Gently i take the figure out of the mold. The ghost I made so that i would be easy to take out of the mold. When you make complicated models it gets very hard to get it out of a one side mold. Then really consider making a two side mold.

Step 7: Preparing the Mould

Silicone attach to almost nothing except silicone. It is very important to grease the mould. Otherwise its sticks together and your mould is ruined. I use for this white vasiline. You can try different types of grease. Make sure you try it before. Some don't respond well on silicone and then it won't harden. I use a brush to get to all the places in the mould, make sure you cover the whole inside and top of the mould.

Step 8: Making the Glow in the Dark Mixture

For making the ghosts i use blue en green glow in the dark pigment. In daylight the look white/yellowish. I prepare 10 ml addition silicone A with 1 ml B component. Then i stir to mix them together. After i have done that i use the scale to check how much Glow in the dark pigment i have to use. The more you use the brighter the ghost will be. Max 50% of the total weight can be pigment. The more you add the less fluid the silicone becomes. Here i used around 15 to 20 %. Stir it well so it becomes liquid without big chunks of pigment.

Step 9: Making the Ghosts

The mixture i pour into the mold. First I fill it up half way and spin the mold around so the inside is everywhere covered with a bit of silicone. I do this to prevent air spots in the mold. then i fill up the mold completely. The straw i use to blow away bubbles that come up. I used quickly hardening silicone and after 40 minutes i can take the ghost out of the mold. And there you have your first glow in the dark ghost. You can see the ghost is flexible. This I repeated three times. For this bouncing ball i made two blue ghosts and one green. MAKE SURE EVERY TIME YOU GREASE THE MOLD!

Step 10: Filling in the Eyes and Mouth

In this stage i fill up the eyes and mouth i made before with the color black. I make a bit of silicone and add black pigment to it. With a knife I drip the black in to the holes and wait till it harden. I do this so when the ghost will light up in the dark the face will be still clearly visible.

Step 11: Preparing the Ball

With the use of a dremel i drill a hole in one side where in a later stadium i pour the silicone in. With my previous project goldfish in a bowl i drilled from the top of one. You can find this on my instagram Gronings Wild.. In this project I want to place three ghost in the ball so i had to change my strategy. the two half balls have to connect to each other after the drilling.

Step 12: Placing the Ghosts

With a bit of soft clay i keep the two half balls stable. I place the ghost to see how I want the ball to look. I want to create the illusion that the ghost are flying inside the ball. I spread the ghost around the ball. Two on one side and two in the other.

Step 13: Filling the Ball

Now its time to fill the ball with silicone. Here i used a special silicone which is completely transparent. This silicone has different properties then the addition silicone. It has less pulling strength. In the solid shape of a ball it works good. You have to mix the two component 50/50. After mixing the two components together I pour it in the two sides of the ball leaving a little space on the top. This i will fill when the silicone is hardened. My idea was to to create a complete transparent ball. The mixture hardened quicker then expected and there where still bubbles inside. A stupid mistake on my part. It is mend as a fun project so i decide to go on and finish the bouncing ball.

Step 14: Last Part of the Filling

When the silicone is hardened i press the two sides of the ball together. The hole I made before i use to fill up the ball. Again i use the straw to get rid of most of the bubbles. I really need vacuum chamber at home! When the ball is completely filled i wait till the silicone is hardened. Then gently i remove the two sides.

Step 15: Finishing the Ghost in the Ball

The last thing to do is gently carve the connecting edges of the bouncing ball. Here i use my knife to get rid of the remaining edges.

Step 16: Your Ghost in the Shell Bouncing Ball Is Ready to Use!

I uploaded a video of the bouncing ball. The ghost charge with daylight or with lights. The longer it is charged by light the brighter and longer the ghost will shine in the dark. When you are in a room with black light it will keep shining bright. I hope to upload a video soon with black light I hoped you enjoyed my instructions in how to make your own bouncing ball. More important how to cast designs in silicone. Feel free to give feedback, tips or ask questions.

When you are curious about other projects please check:

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