Chalkboard Sphere




This instructable will show you how to build a blackboard sphere to write on. Because sometimes a flat area is not enought!

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Step 1: Assemble the Polysyrene Sphere

You have to glue the two pieces together. Pay attention to use a glue intended for polystyrene (some glues can dissolve/liquify it)

Step 2: Add 2 Layer of Cementite (primer)

To make it, I covered a polystyrene sphere with special blackboard painting. I used a cd-r box to hold the sphere in place

Step 3: Add 1 or 2 Layers of Blackboard Paint

Once dry, you can add a layer or two of blackboard paint

Step 4: Add a Support to the Sphere

Use an empty cd box as a stand for the sphere. With a cutter make a small hole and glue the cd-box stick into the hole. I used an hot-glue gun to fill the spaces between the stick and the hole in the sphere

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    12 Discussions


    7 years ago on Introduction

    Using glue to dissolve polystyrene is a way to make simple once-use molds, you simply carve the polystyrene use it as a mold when the model is set use the glue or even better ethyl acetate to dissove the polystyrene to release the model.

    9 replies

    You can also use plain old acetone (sold in most box stores and hardware store to cleaning) - this is also a cool way to "melt" (Doesn't technically melt it) Styrofoam... you can then use the liquified plastic to make things with...


    -oops! I forgot to add that in - Once the acetone is removed (usually just let it evaporate) It will solidify.... I wish I had heard of this method before I tried to melt Styrofoam over and open flame (a lighter)... not only did the Styrofoam not melt but in caught on fire and Styrofoam burns in an irregular way - the flame will worm it's way through the foam, all the while creating a nasty smelling smoke, which I am sure shouldn't be breathed in.

    I was trying to melt Styrofoam to make it into usable plastic... as for smoke inhalation - some types of smoke smell good... like wood smoke, incense etc...