If you plan on making more than a few candles in the next year or so, you'll need to weigh the pros and cons of plastic molds, silicone molds or aluminum molds. The biggest benefit of plastic molds is the cost. They're the cheapest option. Silicone molds often cost as much as aluminum molds and last much longer than plastic. Aluminum molds are the most durable but are probably the most difficult to use. With a little practice, you'll soon find that aluminum molds are the only way to go.
Aluminum molds are built to last and produce supreme quality candles. For most crafters, the most difficult task when using aluminum molds is securing the wick. How the wick is secured depends entirely on the type of mold you're using. Most large aluminum pillar molds have holes in the bottom to hold the wick. Simply thread the wick through the hole and tie a knot on the bottom. You should use a wick holder to make sure the top of the wick stays in place after you pour the wax. For smaller aluminum molds you can often use wick pins. Wick pins look like an aluminum wick with a wide base. Place the pin in the mold and pour in your wax. When the candle is hard, remove the pin and insert your wick.
You must prepare aluminum molds before they can be used. The mold should be treated or coated so the candle slides out easily. There are home recipes for mold treatment available online. Some crafters use liquid glycerin to coat their molds while others suggest using cooking spray such as Pam. We suggest using only professional mold release spray. Spray your molds every 3 or 4 uses and the candles should slide out with ease.
Despite popular belief, aluminum molds do not need to be cleaned after each use. If your wax was the correct pour temperature there shouldn't be any left on the mold. Once the candle is removed, your mold should be clean and still 'slick' from the mold release. When it's time to clean your mold, use warm water and soap. Professional mold cleaner is available but really shouldn't be necessary unless you were sloppy when pouring the wax. If you take your time and pour neatly, there shouldn't be any wax left on the mold after the candle is removed.
With proper care, aluminum molds will last for years. I have some molds that I've been using for 8 years and they still look the same as they did when I bought them. In simple summary, coat your molds before use and keep them clean afterward. Chances are your molds will outlast your car and require so much less upkeep!