Besides the (semi-) professional equipment, the safest way to malt wax is without question the double boiler method. It is also the method most commonly used by the hobby candlemaker.
Inexpensive, adaptive and easy to work with, the double boiler method will accompany you on your first foray into candlemaking and in all likelihood well beyond these first steps.
The principle is simple: a saucepan containing your wax (also called insert) is placed inside another saucepan containing hot to boiling water. Only the outer saucepan is exposed to direct heat.
The result of this is the certainty that the temperature of melted wax will never exceed that of boiling water, or 212°F.
For your very first steps, all you need are two old saucepans that you will use for candlemaking only from that point onward (check your local thrift store). Make sure they fit loosely inside each other, as shown on the picture above. The drawback of this setup is, depending on the model and size of the selected saucepans, a potential lack of stability.
You can minimize that lack of stability by choosing carefully the saucepans you will use: try and avoid too big of a height difference when the inner saucepan is placed inside the outer one. It does not have to be a perfect fit though: a small difference can be taken care of by placing metal brackets at the bottom of the outer pan (you'll find these in any DIY store). Make sure that the melting recipient (insert) is stable and level.
If your melting pot is high enough to stand freely in the outer saucepan, you will have to make sure their bottoms don't touch, otherwise you will lose the benefits of the double boiler concept. Here again, you can use (smaller) metal brackets to raise the bottom of the melting pot by about half an inch, which is plenty.
When you pick the saucepans to use for your double boiler, make sure there's an inch of free space between the outer and inner saucepans. If the fit is too tight, boiling water will tend to burst out of the outer pan like a geyser.
As an alternative, you can shop around and get yourself a ready-made double boiler. They're more expensive than the homemade version (starting at around 30$) but the way they are designed make them more stable, safer and generally easier to use. Keep in mind though that store-bought double boilers are designed to melt delicate ingredients like chocolate or foie gras in rather small portions so their capacity is usually limited. This could quickly become a burden and you may soon abandon your new piece of equipment for something that will allow you to melt larger quantities of wax in a single batch.
You can use a double boiler setup in two ways:
If the first method sounds simpler and requires fewer containers, it has its disadvantages:
I highly recommend the second method. Transferring wax from the melting pot to the pouring pot without spilling will require some getting used to but it's perfectly possible
To make it easier, use a large ladle with a pouring lip.