From Lian's Blog
Last month I made crayon stars in my solar oven. It was super fun. I always have a lot of crayons around because I do a lot of art. I have recycled the broken bits into cool shapes. They make great new crayons, and gifts too.
It is easy to remold crayons. You need:
Teflon candy forms or ice cube trays (we get ours at the dollar store) or muffin tins
can easily peel the labels from crayons by soaking them in water for
five or ten minutes. You don't want to leave washable crayons soaking
much longer than though. Next, cut the crayons into small pieces. The
smaller the pieces the smoother/faster the crayons will melt. I like
bigger pieces to make art with. It is best to separate the colors as you
cut them, but you can mix them any way you want to in the forms. I
really love how the colors mix when they melt.
Fill the forms with your crayon bits. Then you can melt them in the oven. We use the warm setting for ten to twenty minutes depending on how much we want them to melt. The longer you leave it in, the more mixed the colors will be. When I make art I don't let them melt all the way so that the colors and bits can all be seen. You can put them put them in the freezer for fifteen minutes and the crayons will pop out easily.
When I make Christmas ornaments, I add beads and a metal hook to them just before I put them in the freezer.
You can melt the crayons in the sun, oven or microwave. You just need to test to see how long you need for each way.