DOUBLE BOILER INSTRUCTIONS FOR MELTING WAX

While melting wax may seem relatively straight-forward, it is perhaps  one of the most dangerous aspects of candle making. By observing a few  safety precautions, you may avoid many of the hazards that exist in  candle-making.

Safety Precautions:

ALWAYS HAVE A FIRE EXTINGUISHER WITHIN REACH.

 Review the instructions  on the fire extinguisher to familiarize yourself with proper operation.  Hopefully you will never need to use it, but if you do need it, you will  not have time to read the instructions. For small wax fires, you may  use something such as a pot lid to smother the fire. Never use water to  extinguish a wax fire. Liquid wax behaves much the same way as oil, and  therefore needs to be treated like an oil fire.

NEVER LEAVE MELTING WAX UNATTENDED. 

It  may seem to take a long time to get the wax to go from solid to liquid.  But once it has liquefied, the temperature will rise sharply. Make it a  habit to constantly monitor the temperature of your wax. If that wax  reaches the Flash Point, then the vapors produced are extremely  flammable. The flash point of wax is typically above 300° F. Never let  your wax exceed 250 degree F.

ALWAYS USE A DOUBLE BOILER.

A double boiler  helps distribute heat and prevents dangerous temperatures. Never melt  wax directly on your stove.

USE AN ELECTRIC HEAT SOURCE IF POSSIBLE.

If, by accident, your wax  reaches the flash point, it is less likely for the vapors to find a  flame and become ignited on an electric heat source. Any open flame,  such as that found on a gas stove, will ignite wax vapors.

ALWAYS USE A THERMOMETER TO MONITOR YOUR WAX TEMPERATURES. 

If you don’t have a thermometer, purchase one here before you start making candles.

Double Boiler Description:

A double-boiler is created by boiling a pot of water on a heat  source. The temperature of the water will never exceed 212 deg. F. We  then place the pouring pot (containing  the wax) within this boiling water. In essence, the pouring pot is  never in direct contact with the heat source. The boiling water  transmits the heat to the pouring pot quickly and evenly, without  scorching the wax and minimizes the chances of a fire. Even with a  double boiler, do not leave it unattended.

General Double Boiler Set Up:

1. Select an old pot that is large enough to place your pouring pot into.
2. Add an inch or two of water to the old pot.
3. Bring to a boil.
4. Place your pouring pot directly into this boiling water. You may  wish to place a metal cookie cutter, or similarly shaped item in the  bottom of your old pot to elevate the pouring pot.
5. Lower the heat to a simmer. It is not necessary to have a rapid  boil. Simmering water and rapidly boiling water are the exact same  temperature, 212° F.
6. Periodically add water to replace water lost to evaporation. Do not let the double boiler run dry. It can quickly get too hot.
7. Allow the wax to melt and monitor the temperature until you reach  the temperature needed for the particular type of wax you are working  with.

source: candletech.com