Crayon Recycling Kit

You might have jar of old broken crayons. Or maybe your crayon just broke in half. Use this kit to cast a new one. 

You can either cast silicone mold, or print a plastic one. However i was unable to successfully cast crayon in printed mold (even though it should be possible). Therefore i recommend you to cast a silicone mold.

Casting silicone mold

1. Print one Crayon Mold Base
2. Print one Crayon Mold Side
3. Print six pieces of Crayon Mold Pin
4. Assemble Crayon Mold Base and Crayon Mold Side
5. Prepare two part silicone, i used around 30 g of mixture
6. Optionally degass silicone mixture
7. Pour silicone into assembled mold and let it cure
8. Carefully remove cured silicon
9. Repeat this process to create two parts of silicone mold
10. Assemble mold 
    1. Insert six Crayon Mold Pins into one mold half
    2. Assemble two silicone parts together
    3. use rubber bands or tape to fix the mold
11. Proceed to section Casting crayons for next steps 

Using printed mold

Using printed mold is simpler procedure but it can be tricky to get the cast crayon out. I was unable to do so.

1. Print two halves of Crayon Mold
2. Print six pieces of Crayon Mold Pin
3. Post processing and fitting
   • top face of each mold half should lay flat on each other, you might need to sand them
   • pins should slide to mold but should not wobble (transition fit), you might need to sand the pins a little
4. Assemble mold (secure both halves with rubber bands or tape)
5. Proceed to section Casting crayons for next steps

Casting crayons

Once you have mold created you can start with casting.

1. Get small container that can be heated and allows you to easily pour molten wax
   • you can either heat it water bath, in that case you can just cut small PET bottle
   • or you can heat it on stove, in that case you can use tin cup or small pot
2. Put crayon bits into container
3. Melt the wax in container
4. Carefully pour molten wax into mold and let it cool down
5. Carefully unmold your new crayon

Finishing and notes

• You can print provided labels (or create your own) and use wood/paper glue to secure it on your new crayons
• Melting and pouring wax is not particularly dangerous, but you should still be careful not to get burned (and not to spill colored wax everywhere)
• You should recycle any (recyclable) trash that is created in the process
• Finished crayons are 83 mm long and have 12 mm in diameter
• The wax will shrink as it cools down - you should 

If you like casting check out my Silicone Soap Mold