Things You'll Need
Flat rock or natural stone tile
Glass wick tube
1 1/2 feet of 1/8-inch thick wick
Flat glass ashtray
Flat rock oil candles, made of slate or other natural stones, combine the beauty of stone with an ambient flame. A flat rock oil candle makes it appear that a flame is coming out of a rock. Aside from the beauty they provide, flat rock oil candles are economical, too, as you never have to replace the entire candle, you only have to add more oil.
Place the masonry bit in your drill and drill two holes into your flat rock, making them the appropriate size to fit your glass wick tubes. Drill the holes about 2 to 3 inches apart.
Set one washer, large enough for the glass wick tube to fit through it, into each hole in the rock. The washer acts as a buffer between the rock and glass. Place one glass wick tube in each hole to serve as a wick holder and a ventilator, setting them in so the tops of the glass tubes are flush with the top of the rock.
Insert one end of the wick into one of the glass wick tubes and feed it through until it comes out of the bottom of the rock. Of the 1 1/2 feet of wick, only an inch or so needs to be visible at the top. The remainder will sit in the oil beneath the rock.
Fill your glass ashtray three-quarters of the way with lantern oil. Place the flat rock with the glass wick tubes on top of the glass ashtray so the length of wick is soaking in the lantern oil. Allow the wick to soak until the oil saturates up to the top portion of wick.
Light the candle wick in your flat rock oil candle. After extinguishing the flame and letting the wick cool, pull the wick up as needed and add more oil to the glass ashtray reservoir.
Oil can spill easily if someone bumps into your candle. Place flat rock oil candles out of the reach of children and pets.