Continuous Burn- How To Do It (Somewhat) Safely
Okay, first thing's first... what's a continuous burn? It's when you light a candle and burn it all the way down to the end in one straight shot.
Safety enthusiasts would have a heart attack over this. I'm in a lot of candle-maker's groups on Facebook, and I can just picture what they'd say to me about this.
"NEVER burn a candle for more than 4 hours at a time."
"NEVER take your eyes off a candle while it's burning."
Etc, etc, blah blah blah.
The truth is, just lighting a flame in the first place is a fire hazard. Having a candle burning at all puts you at risk of starting an unintended fire, at least to some degree.
And yeah, for all intents and purposes, you should never leave a candle burning unattended. You should also technically put it out after about 4 hours and let it cool to prevent the container from getting way too hot and shattering.
With that being said, we here in the spiritual community generally do things a little differently, especially when it comes to candles we're using on the altar. You might be familiar with the "7-day candle" that is typically left on the altar to burn 'round the clock without interference. I've been in many households where this is a common practice. I've also found this to be pretty common in some churches and at public shrines. Those candles are lit and left to burn themselves out, only to be replaced by fresh ones when that time comes.
While I can't sit here and claim that it's a safe thing to do, there are ways that you can drastically reduce the risk of starting a fire with a candle that's left to burn itself out. If you're going to do this, here are some easy ways to make this practice a bit safer.
1. Give it space.
This is especially true if there is ever going to be a period of time that you won't be watching the candle. An object that's nearby could catch fire if the flame gets too big and jumps, if the wax spills over and ignites, if the wick burns too fast and sparks, or any number of similar events happen to take place while you're not looking. It's best to keep the candle at least 12 inches away from anything else while it's burning, including the wall.
2. Trim the wick before you light.
Generally, your wick should only be about 1/4 of an inch long. Most of the time, the wick on a brand new candle is way too long to safely burn. When the wick is too long, that's what causes those crazy tall flickering flames. Not safe. Trim it before you start and you'll eliminate a bunch of issues right away.
The picture below shows a wick that I trimmed before burning. It's still just a wee bit long, but it passes.
3. Use a heat-safe surface.
Once the candle burns down to the very end, the container is going to get HOT. Burn the candle on a surface that can take that kind of heat. I personally use a baking sheet layered with foil. You can also use a heavy pan, a cement or clay surface (although these might end up with burn marks), or any container that's rated as "fire safe."
4. Use a bowl of water.
The longer you burn a candle, the hotter the container will get. When you put the candle out, you're giving the container a chance to cool off before you light again. Since we're not doing that here, placing the candle in some water will help keep that jar cool, especially as it burns down to the bottom. A jar that gets too hot will likely shatter. Not only is the broken glass a problem, but that's a good way to unleash a fire on anything that happens to be near the candle when the jar bursts.
I keep mine in a small metal mixing bowl with about an inch or so of water. This is an especially good idea if the candle you're burning is "fixed" with herbs or any other additives besides wax. When all of the wax burns out of the jar, the herbs might catch fire and burn for a moment across the bottom of the jar. If the jar hasn't shattered from the heat of the hot wax yet, this is sure to do it! The water is a huge help in preventing this.
Like I said, there's really no way to burn a candle that is 100% safe. That's especially true if you're doing a continuous burn. However, using as many of these tips as you can will definitely help drastically reduce the risk.