There are any number of situations in which candles can be useful… when the power is out and you need some light, or just to provide a modicum of warmth in a greenhouse to protect your crops from freezing. Most candles don’t last more than a few hours at most, but this video shows how you can make a candle that will burn for days — and it’s cheap!
He uses some cheap vegetable fat, which is sold under the name Trex in the UK (where he is). In the USA I would think Crisco vegetable shortening would do the job. Melt the shortening and pour it into a pre-warmed glass jar that’s about an inch taller than your wax candle. Let the fat cool until it’s a semi-solid, then insert the candle into the middle of the jar until it’s fully surrounded by the fat.
Let the entire thing cool down until the fat is solid, then create a circular gutter or moat around the candle. You’re done!
The fat serves as fuel for the flame, which of course makes a standard candle last much longer than it would if you burned it alone.
The video contains some burn results, as he fires it up and leaves it for 12 hours before checking on it. After half a day of burning, it burns down less than an inch. After 48 hours, about two-thirds of the fuel still remains in the jar. 72 hours in, more than half of the fuel is still left!
The candle he made for this video burned for an incredible 120+ hours, and still had some fuel remaining in the jar when it went out. Amazing!
Read more: alloutdoor.com