Why do candles tunnel? 10 tips to make your candle burn evenly
Do you have dozens of old candles lying around, with a ridge of wax around the edge and a wick that refuses to light? It can be super frustrating when your favourite candle tunnels. But luckily, there are some simple things you can to stop your candles from tunneling, or to save your candle if it has already tunneled...
What is candle tunneling?
Tunneling is the term used to describe when a candle flame burns a tunnel down the middle of the wax, rather than creating a pool across the entire surface of the candle.
What causes candle tunneling?
There are a few reasons why your candle might start to tunnel. Firstly, and most commonly, tunneling occurs when you only burn the candle for short periods at a time. When you light a candle, any wax that melts will remain soft and therefore melt more easily upon the next burn - this is known as ‘wax memory’.
Because of this memory, if you only light the candle for short periods, only a small circle of wax will melt, meaning with every subsequent burn, that small inner circle will melt more quickly than the rest of the wax.
Other reasons for tunneling include keeping a wick too short, moving the candle as it burns, keeping the candle on an uneven surface, or keeping a candle close to draughts.
How to stop candles from tunneling
Tunneling leads to lots of wasted wax on the sides of the candle, so it's important to nip any tunneling in the bud to ensure you can make the most of your candle. Here are 5 tips to stop your candles from tunneling
1. Let the top layer of wax melt
The number one way to avoid tunneling is to make sure you allow the top layer of wax to fully melt every time you light the candle, before extinguishing the flame. For a regular-sized candle, this will usually be around 1 to 2 hours.
2. Don't move the candle as it burns
Do some of your old candles have wax buildup focused on one side? This could be because you moved the candle while it burned. This movement causes liquified wax to flow to one side, and the increased distance from the flame causes it to quickly solidify on the side.
This issue is easily resolved by not moving your candle while it burns. It's also improtant to wait for the wax to solidify again before moving it. Moving the candle while the wax is still liquified could cause it to harden unevenly.
3. Make sure the wick isn't too short
If a candle's wick is too short, it prevents the flame from growing big enough to effectively melt the top layer of wax. Instead, the tiny flame will only melt the wax immediately around and beneath it, causing a candle to tunnel quickly.
While it is important to trim your wick, to prevent a candle flame from becoming too tall and sooty, make sure you trim it to approximately 1/4 inch - no shorter!
4. Keep the wick straight
A wonky wick is another potential reason why your candle has more wax built up on one side of the container. If your wick is leaning to one side when you go to light the candle, the flame will similarly lean to that side, causing the wax on one side to liquify more quickly than the other side.
As previously explained, wax has memory, meaning any wax that liquifies will soften more easily upon subsequent burns. Therefore, if your wick and flame are wonky on the first burn, it's likely that your candle will continue to burn more quickly on one side, as this wax will be softer.
To fix this issue, carefully straighten the wick before lighting it, using either your fingers, or a pair of tweezers.
5. Place the candle on a level surface
If your wick is perfectly straight, but your candle continues to burn more on one side, the surface your candle is placed upon could be to blame. You might not think your table is wonky, but even the slightest lean could cause your candle to burn unevenly. Whip out your spirit level and check if in doubt!
How to save a tunneled candle
If your favourite candle has tunelled, fear not! There are some simple tricks you can do to save it...
1. The hairdryer trick
One simple way to melt down the wax on the edges of the candle container is to blast it with a hairdryer. Ramp your hairdryer up to the highest heat setting and point it at the candle until the entire top layer has liquified.
Once the wax has re-hardened, you'll have a 'blank canvas' to start again. (Just make sure you follow our tips above to prevent the candle from tunneling again!)
2. The oven trick
If you don't have a hairdryer (or you don't fancy holding a heavy hairdryer for that long!), another way to melt tunneled wax down is to use the oven.
Set the oven to around 80 degrees Celcius (175 degrees Fahrenheit) and carefully place your candle into the oven on a baking tray. Remove the candle (using oven mitts!) after roughly 5 minutes, or when you can see the top layer of wax has melted. Allow the wax to harden, then light the candle as usual!
3. The foil trick
Don't fancy getting the oven or hairdryer involved? Try using the candle's own heat to melt down the wax!
Simply light the candle, then carefully place a foil 'tent' on top of the container. This will evenly reflect the candle's heat onto the entire wax surface, causing it to melt. Once the wax is fully melted, carefully remove the foil using oven gloves, then use your candle as normal.
Safety note: Be sure to poke a small hole in the foil tent so smoke can escape. Monitor your candle very closely when using this method, as it can quickly cause overheating. For all of these methods, make sure your candle's container is fully heatproof.
4. Physically remove the unmelted wax
If you don't fancy getting heat involved, a safe way to save a tunneled candle is to simply remove the wax from the sides of the container. This can be done using a spoon or blunt knife.
Simply scrape the wax away from the sides of the candle, until you're left with an even surface of wax. Then, light your candle and enjoy! Just make sure you let the top layer fully melt this time.
5. If all else fails...make wax melts!
Unfortunately, some tunneled candles are beyond repair. However, this doesn't mean they are entirely useless. If you do have an old candle that won’t light, but still contains leftover wax, why not make your own wax melts?
Simply remove the leftover wax and melt it down (click here for our guide on removing leftover wax from a candle!). Then, pour the liquified wax silicone molds. Allow the wax to re-harden, then pop your homemade wax melts onto a wax burner and enjoy!