Salt makes candles burn longer because it raises the melting point of the wax melt pool. The candle will require just a little more heat to burn resulting in a longer time. Sprinkle just a dash into the wax melt pool.
Homemade wicks are made by soaking the cotton core in a saltwater mixture as a flame retardant.
Too much salt will clog a candle wick. A candle wax fire can be put out with salt.
- Candle Making FAQ