Soy candles burn longer. Drafty areas will affect candle burning times as candles will burn slightly quicker.
Because of the nature of temperature, you may see some "frosting" on the top of your candle. It's the nature of using 100% soy wax and will in no way affect burn time.
Candle burning times will also vary depending on the height of your wick so make sure to trim off/break off the burned wick to 1/4 inches when possible
4oz averages 20-30 hours
6oz averages 30-40 hours
8oz averages 60-70 hours
The cast iron candles burn a bit differently because they are a multiple wick candle. But once the candle burns down, the wicks can be removed and you can enjoy the candle, sans wicks, on low heat on your kitchen stove. Once the candle has completely burned down, clean the cast iron pan and it can be used for regular cooking. See the link below as we only use LODGE™.