How to fix a tunneling candle
Tunneling leaves a wall of wasted wax around a deep hole. Learn why it happens, three safe ways to fix it and how to stop it from coming back.
What tunneling looks like
A tunneling candle burns straight down the center and leaves a thick ring of unmelted wax around the sides. The hole gets deeper with every burn. Eventually the flame sits at the bottom of a narrow well, struggles for air and may drown in its own wax. All the wax in the outer ring, and the fragrance in it, goes to waste.
Why it happens
- Short first burn: the most common cause. The candle remembers a small melt pool. See the memory ring.
- Short burns afterwards: lighting a big candle for 20 minutes at a time.
- Wick too small: less common in tested candles, but possible.
- Drafts: air blowing across the flame pushes heat to one side.
- Multi-wick candles burned with one wick: each wick is meant to cover only part of the surface.
Fix 1: the long burn
If the tunnel is shallow, about 1 cm or less, light the candle and let it burn until the melt pool reaches the sides. This can take a few hours, but do not exceed about 4 hours. Often that is enough to reset the memory.
Fix 2: the foil collar
This is the best-known method for deeper tunnels.
- Take a sheet of aluminum foil and wrap it around the top of the jar, so it covers the outer ring of wax.
- Leave an opening in the center about 2.5 cm (1 inch) wide, so the flame has air.
- Light the candle. The foil reflects heat back onto the hard wax and helps it melt.
- Check every 30 minutes. Remove the foil carefully with an oven mitt once the surface is level, because it gets hot.
Fix 3: gentle heat from above
Some people use a hair dryer on a low setting, held at a distance, to soften and level the outer wax before lighting, then let the candle burn normally. Never put a candle jar in an oven or microwave, and never use a heat gun close to glass, which can crack.
When to give up
If the wick is too short to reach above the wax or the tunnel is very deep, the candle may not recover as a candle. You can still enjoy the fragrance: break up the remaining wax and use it in a wax warmer, as explained in candles, diffusers and melts.
Prevention
| Habit | Why it helps |
|---|---|
| Long first burn | Sets a full-width memory |
| Burn sessions of 2 to 4 hours | Keeps the pool wide every time |
| Light all wicks together | Melts the whole surface |
| Keep away from drafts | Spreads heat evenly |
| Trim before each burn | Keeps the flame healthy |
The foil method makes the jar and foil very hot. Stay with the candle, keep it on a heat-proof surface and never touch the foil with bare hands while it is burning.
