Metal or aluminium candle molds are probably the most expensive to purchase.
But their very material makes them (almost) everlasting and, as long as you look after them properly, manipulate them with a minimum of caution to avoid shocks and blows and clean them thoroughly after usage, they will last you a lifetime.
Metal candle molds are a very good long-term investment
Metal molds are available in a wide variety of shapes, for instance: cylindrical, oval, square, conical, starshaped, pentagonal, hexagonal and othergonal, triangular...
Some metal molds, mainly those made of aluminium and tin, can be labelled seamless. This means that these molds do not have a welding line (a cavity in the metal where the mold has been "closed") and you won't get a replica of this line on the finished candle.
However, just because a mold you like very much is not seamless should not be a reason to give up on it: the seamline is relatively easy to get rid of with a Stanley knife and an old panty hose to polish out the candle afterwards.
The edges of a metal mold, in particular the edges of the square base, can be as sharp as razorblades.
If, like me, you're not great at mental calculation, you'll want to preserve your ten fingers by covering the sharp edges of your metal molds with one or two lengths of thick insulating tape.
How to wick a metal mold?
Usually, you'll find a pre-drilled hole in the center of the mold's base. This hole, sometimes closed with a screw, is the wick hole.
- use a screwdriver to remove the screw (if any),
- thread the wick through the hole at the bottom of the mold, up through the length of the mold and out the top. Leave a length of about 2 inches of wick at both ends,
- on the "open" side of the mold (the top), use a wick holder to keep the wick in place, centered and tight or just tie the wick around a pencil,
- on the other side, the base of the mold, slightly pull on the wick to tighten it, place the screw back in the wick hole and screw it shut. This should keep the wick tight enough during the pouring procedure,
- now cover wick, screw and wick hole with a generous amount of mold sealer. Use enough of it, you don't want paraffin to escape and invade your whole work area as soon as you've poured it,
- your mold is now wicked and you're ready to pour your candle.
Taking care of your metal molds
- when you're done using your metal mold, clean it thoroughly and store it away safely from dust and accidental blows, ideally inside its original box, or in a fitting box you found.
- it is almost impossible to remove a candle from a mold whith dents in its edges (or body). So always be very careful not to drop your metal molds or hit them by accident with, for instance, a pouring pot.
- if there's any wax left inside the mold, you will probably see it reappear on the next candle you'll make in it. Residual wax could also make it hard to unmold the next candle you make. Clean your metal molds properly with mold cleaner or with your heatgun and some kitchen paper.
- do not pour wax at too high a temperature in metal molds, you could potentially damage their welds.