We've been snowed in for two days now and the snow keeps coming. Isaac and I decided to have a bit of a clean out of his old crayons and make some rainbow crayons. Easy to do and gives those icky looking old bits of crayons a new life. Break up your old crayons into pieces and place in a silicone mould, (we used a brownie pop mould). You can use metal muffin pans if you like but the crayons may have a tendency to stick. They pop right out of the silicone moulds nicely.
Place in a 150C (250F) oven for a few minutes - maybe 10-15. It will depend on the type of crayons you used. Keep an eye on them and when they are evenly melted let them cool before popping them out.
We set them outside in the cold to firm up and voila! New crayons.