Liquid inside, gas outside
Clipper's safety data sheet puts it in one line: inside the lighter the fuel is a liquid, outside it is a gas. In a Clipper that fuel is more than 95 percent isobutane, at a pressure of about 2.3 bar at 20 °C. That pressure is what keeps it liquid in the tank.
At the top sits the valve. When you press, it lets out a small, fixed amount of fuel. How it does that depends on the design. An old patent, later owned by BIC, describes two kinds side by side: lighters that pass the liquid through a fine membrane where it evaporates, and lighters that only draw the gas sitting above the liquid. Both are built to be used upright.
What happens when you tilt it
When you tilt the lighter, the liquid moves inside the tank. It can then reach the valve through a path meant for gas, or arrive there in larger amounts than when the lighter is upright. That liquid only evaporates at the burner. One litre of liquid butane makes about 230 litres of gas. So a few drops give far more gas than the valve normally lets through, and all of it burns at once.
Swedish torch maker Sievert describes the same thing with gas torches: used at a steep angle or upside down, liquid gas gets into the burner and the flame becomes much larger and hotter than the torch is built for. Their advice: keep it upright.
Sometimes you also see burning droplets flying off the flame. The ISO 9994 standard calls this spitting or sputtering: liquid gas that did not have time to evaporate. The opposite can happen too: according to the same patent, a change of position can form vapour bubbles in the liquid, and the flame flickers or suddenly gets smaller.
Is your lighter faulty?
Not necessarily. Some lighters are made to do this on purpose. ISO 9994 defines them as automatically adjusting pipe lighters: lighters whose flame grows by design when tilted from an upright position. Even those may never produce a flame higher than 100 mm, in any position.
An ordinary lighter is made to be used upright. BIC says so for its long-neck lighters: no more than a 45 degree angle. Clipper promises a stable flame of 30 mm at most for the whole life of the lighter, but does not say what happens when you tilt it. A flame that rises a little at a steep angle is physics, not a fault. A flame that flares up while the lighter is upright is a different matter.
Other reasons for a flame that is too big
Tilting is the best known cause, but there are four more:
| Cause | What you see | What to do |
|---|---|---|
| Flame set high | A tall flame even upright, only on an adjustable lighter | Turn towards minus and start low |
| Warm lighter | A taller flame after sun, a car or a radiator | Let it cool to room temperature |
| Just refilled | A burst of flame on the first click | Wait a moment before lighting |
| Jet flame | A blue, roaring flame that looks fierce | Normal, that is how it is made |
The flame is set too high
A classic Clipper has a fixed valve: you cannot adjust its flame. A Clipper Jet and most storm lighters from Silver Match, Prof and Champ High do have an adjuster, on some models for example a wheel underneath. ISO 9994 requires the lighter to show which way makes the flame higher or lower. If it is set to maximum, the flame will be bigger than you expect when you light it.
The lighter is warm
The warmer the gas, the higher the pressure. For isobutane the pressure at 35 °C is about half as much again as at 20 °C, and at 50 °C more than double. In the patent mentioned above, the flame of an ordinary lighter grows along with it. A lighter left in the sun or behind a windscreen gives a bigger flame. Clipper's safety data sheet says: do not store above 50 °C and do not leave it in the sun for long.
You have just refilled it
After refilling, some gas hangs around the valve and in the air. Light it straight away and that gas catches too: a short burst of flame. In its own video Clipper advises waiting a moment after refilling so that gas can clear. Lighter maker Colibri asks for two minutes, which also lets the lighter come back to room temperature. For a clean refill, see how to refill a Clipper lighter.
It is a jet flame
A storm lighter mixes gas and air before burning. That gives a narrow blue flame that roars and resists wind better. It looks bigger and fiercer than the yellow flame of a classic Clipper, but that is its job. The standard is even stricter for it: as delivered, 60 mm at most. Not sure which type suits you? Read which storm lighter to choose.
How to keep the flame small and safe
- Hold the lighter upright. For a candle deep in a jar, use a lighter with a long or bendable neck, like the ones you find at Champ High, rather than tilting your everyday lighter.
- Start low. Set an adjustable lighter to its lowest position, light it, and only then turn it up to the height you need.
- Wait after refilling. Let the gas around the valve clear and the lighter return to room temperature. Colibri sets the adjuster to minimum before filling, then a quarter turn up afterwards.
- Keep it cool. Not on the dashboard, not on a sunny windowsill, not on a radiator. Below 50 °C, says Clipper.
- Keep your face and hair clear on the first click, especially after refilling or when you do not know how the adjuster is set.
When to stop using a lighter
ISO 9994 requires a gas lighter at its highest setting not to flare or spit burning droplets. If yours does that while upright, even on the lowest setting, or keeps burning after you let go, stop using it. A smell of gas or a hiss while you are not using it means it leaks. For other problems, such as no spark or no flame, see Clipper lighter not working.
A lighter that still holds gas does not belong in the household bin. Where it does go is explained in how to throw away a lighter. For a new one, browse the Clipper lighters and the storm lighters.
