What is a SFX Flamethrower?

In Hollywood for film & TV, Liquid Propane flamethrowers are used more often than gasoline based flamethrowers. If you’re seen a flamethrower on TV, chances are it was actually propane based. Gasoline flamethrowers can drip onto the set, and the flaming liquid has to land some on it’s target unless it burns up mid-air. Liquid Propane burns faster than gasoline, allowing the actor or stunt-worker to shoot it anywhere without worrying about the flaming liquid landing on a target - such as an angle pointing it at th e camera. Gasoline flamethrowers are used when long range is needed for the shot. Sometimes both will be used in the same scene but for different shots, such as in Aliens.

Ripley in Aliens using a flamethrower against the Xenomorph nest.
Yogurt in Space Balls demonstrating SpaceBalls The Flamethrower (the kids love this one)
Scene from The Watchmen with The Comedian lighting a cigar using a flamethrower, that is actually a propane torch.
MacReady using a flamethrower in The Thing.
Night Of the Creeps use of a Propane Torch modified to act as a flamethrower.