we used old candles to make new ones. it’s easy to do and lots of fun for the kids.
use a cardboard box, paper rolls, cookie cutters or other shapes and fix the wicking (with some melted wax or by piercing it through the cardboard) in the middle of the mold. tie the end of the wicking to a toothpick and lay it over the mold to prevent loosing it once you pour in the wax. if you don’t have a wicking at hand you can also use a thin candle and place it with some melted wax in the center of the mold. to seal up the bottom corners of the box wrap some tape around them.
put the old candles in a tin and place it in a pan filled with water. heat the water (it shouldn’t boil) and let the candles melt. add an old crayon to the wax and let the wax cool down a little. then pour the wax into the molds. we first added one pink crayon to the wax and poured some of it into the molds. we then let the wax cool off a little and added another, red crayon to the melted wax. again we poured this wax into the molds and let it dry. you can do this over and over again until the molds are filled up.