To make a round candle, you need a round mould. Round candle moulds come in various sizes and are usually made from two halves that are clamped together. The exact method used to close a round mould depends on its type. You can buy these moulds wherever candle-making supplies are sold, and they work with any type of candle wax.
Fill the bottom section of a double boiler half way with water. Place it on a hob burner set to medium heat. Place the top of the double boiler over the bottom section.
Put candle wax chunks into the top section of the double boiler. Check the round candle mould packaging to see exactly how much wax you need.
Stir the wax with a wood spoon to keep it from burning. Stir until the wax is completely melted. Add any dyes or fragrances you may want to use only after the wax is melted.
Thread a wick through the small hole at one end of the candle mould and then through the larger hole at the other end of the mould. Tie the wick to a pencil so it sits on top of the large hole. Trim off the excess wick with scissors.
Place mould sealer over the smaller hole and the piece of wick sticking out of it.
Place the rubber seal that came with your mould in between the two halves of the mould (some may not come with, or therefore need, a seal).
Clamp the two halves of the mould together using the fasteners that came with the mould. Set the mould on top of its stand, large hole facing up.
Pour the melted wax slowly into the mould. Allow the wax to dry completely, which takes about four to six hours.
Touch the outside of the mould. If it is completely cool and the wax has been sitting for at least four hours, undo the fasteners, remove the mould sealer and pencil, and pull off the mould itself from the candle.
Use a hobby knife to scrape off any wax bumps. CandleHelp.com recommends smoothing the candle's surface with a piece of nylon hose.