We did this one afternoon, and it was a success!
Old broken crayons (remove the paper)
Old muffin tins (I used cupcake liners in my muffin tins)
Heat the oven to 250 degrees. Place old broken crayons in the muffin liners. We only filled each one about ½ full. Heat in the oven until crayons have melted. Let cool for several hours. Enjoy your new crayons.
Have your kids practice mixing colors with this activity. My son just wanted to put every color together.
Do you have a good recipe for making crayons?