How to recycle crayons into fun-shaped rainbow crayons

rainbow crayons of darth vader, han solo, and lego minifigs on a countertop

Luke, I am your crayon. PopSci

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Eventually any pristine box of crayons ends up as a pile of busted stubs at the bottom of a craft bin. In the U.S., between 45,000 and 75,000 pounds of crayons end up in landfills every year and traditional paraffin-based crayons are not biodegradable. Instead of trashing broken crayons, give them a new, colorful life by creating rainbow crayons.

This simple DIY project can also be a fun lesson for kids on the states of matter. The crayons start as a solid, melt into a liquid at temperatures above 120 degrees Fahrenheit, and return to a solid when removed from heat.

[Related: How to Frankenstein old wax scraps into a totally new candle]

The best part about creating recycled crayons is that you’re not limited to boring old pencil-like shapes. With silicone molds, you can create crayons in the shape of Darth Vader, a Lego minifig, flowers, sea stars, or even Han Solo frozen in carbonite.

What you’ll need to make recycled rainbow crayons

Ingredients

  • 2-3 cups broken crayons with paper removed
    Note: You can use new crayons, but where’s the fun in that?

Tools

Activity Time

  • 30-60 minutes, depending on your method for peeling the paper off the crayons.
crayon melting supplies on a kitchen countertop: crayons, molds, baking sheet, wire rack
If you also have a bin of broken and busted crayons, this might be the perfect weekend project for you. Photo: PopSci

Directions

  1. Pre-heat oven to 250-degrees.
  2. Peel paper off crayons.
    Note: To speed up the process, soak crayons in tub of water first. To slow down the process (and keep little hands occupied), don’t soak.
  3. Break or cut crayons into 1/4 to 1/2-inch pieces.
  4. Arrange crayon chunks in silicone molds. You’ll want to slightly overfill the molds.
  5. Place molds on baking sheet or wire rack.
  6. Bake crayon chunks for 8-10 minutes, or until all crayon chunks are melted.
  7. Remove molds from oven and allow to cool (approximately 25 minutes at room temperature or 10 minutes in the freezer).
  8. When fully cooled, carefully remove the crayons from the molds.

That’s it! Now grab a coloring book or sheet of paper and color away.

colorful crayons in the shape of lego bricks and lego minifigs
You can’t build anything with these Legos, but they’re still fun. Photo: PopSci