Alternately, dripped wax can melt the candles together. The most efficient engines are single-file . They get maximum oxygen and cooling area. To conserve space, engines can also be made double-file . Here two single-files are melted together.
Melted wax holds the engine to the frame.
Technologically advanced balloonists can apply the information to design large volume Christmas Candle Balloons, or Homemade Candle Balloons, which can burn for around forty minutes. Candle Powered Paper Hot Air Balloons can also be designed. For any type of experimental fire balloon, it is not a good idea to rely too much on an outside heat source. Otherwise a too-heavy balloon might climb up at first, then land, risking a crash and burn. Remember that fire balloons might be considered to be fireworks, and potential fire hazards.