# What is the propellant in a flamethrower? **URL:** \ **Category:** Factual Questions\ **Created:** [October 17, 2014, 4:43am UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568 "2014-10-17T04:43:28Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![handsomeharry](https://avatars.discourse-cdn.com/v4/letter/h/e9c0ed/32.png) [@handsomeharry](https://boards.straightdope.com/u/handsomeharry)\ **Post date:** [October 17, 2014, 4:43am UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/1 "2014-10-17T04:43:28Z")
Some friends and I were discussing military flamethrowers, and everybody was wondering what the propellant was. The flames can go something like 20-100 feet, if I recall my war history footage correctly. Somebody said it was the chemical reaction between liquids/gases in the two tanks, and others said it was pressurized, which, given the distances, doesn’t make sense to me. A Wikipedia search didn’t help, and, usually, a Google search turns up some improvised survivalist formula, or else, nothing at all. Can anybody help? Thanks, hh ---
**Author:** ![AClockworkMelon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aclockworkmelon/32/10803_2.png) [@AClockworkMelon](https://boards.straightdope.com/u/AClockworkMelon)\ **Post date:** [October 17, 2014, 5:10am UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/2 "2014-10-17T05:10:04Z")
I’m pretty sure they just spray gasoline. It comes into contact with a propane torch flame on the way out and catches fire. Edit: Wikipedia mentions that the gas has a “thickening agent” in it, which makes sense. ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [October 17, 2014, 7:02am UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/3 "2014-10-17T07:02:07Z")
According to the Wikipedia, the propellant is compressed nitrogen gas, in one of the tanks: > [@](#): > > The backpack element usually consists of two or three cylinders. In a two-cylinder system, one cylinder holds compressed, inert propellant gas (usually nitrogen), and the other holds flammable liquid—typically petrol with some form of fuel thickener added to it. A three-cylinder system often has two outer cylinders of flammable liquid and a central cylinder of propellant gas to maintain the balance of the soldier carrying it. ---
**Author:** ![handsomeharry](https://avatars.discourse-cdn.com/v4/letter/h/e9c0ed/32.png) [@handsomeharry](https://boards.straightdope.com/u/handsomeharry)\ **Post date:** [October 17, 2014, 11:28am UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/4 "2014-10-17T11:28:29Z")
Thank you, **Sage Rat** and **AClockworkMelon**. I don’t have any idea why/how I missed that Wikipedia info. :smack: ---
**Author:** ![JKilez](https://avatars.discourse-cdn.com/v4/letter/j/e5b9ba/32.png) [@JKilez](https://boards.straightdope.com/u/JKilez)\ **Post date:** [October 17, 2014, 12:06pm UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/5 "2014-10-17T12:06:48Z")
There was another propulsion method: [QUOTE=Wikipedia] Some Soviet Army flamethrowers had three backpack fuel tanks side by side. Its user could fire three shots, each emptying one of the tanks. The mechanism used to empty the tank was not a pressurized gas cylinder but a black powder cartridge on each fuel cylinder. [/QUOTE] I have seen flamethrowers that were powered by (what looked to be) 12 gauge shotgun shells. ---
**Author:** ![Hypno-Toad](https://avatars.discourse-cdn.com/v4/letter/h/b2d939/32.png) [@Hypno-Toad](https://boards.straightdope.com/u/Hypno-Toad)\ **Post date:** [October 17, 2014, 2:24pm UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/6 "2014-10-17T14:24:40Z")
> [@JKilez](#): > > There was another propulsion method: > > I have seen flamethrowers that were powered by (what looked to be) 12 gauge shotgun shells. This is the kind I’ve seen, the [LPO-50](https://www.google.com/images?q=LPO-50+flamethrower&hl=en&gbv=2&sa=X&oi=image_result_group&ei=aiZBVOKNDo6NsQTkoYAY&ved=0CBQQsAQ). The issue with that model is that you get only three shots, one from each tank. You have to fire the whole tank in that one shot. And you had better be laying down, because the kick is powerful. On the other hand, it has better range than most (70 yards). ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [October 17, 2014, 2:56pm UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/7 "2014-10-17T14:56:08Z")
> [@AClockworkMelon](#): > > Wikipedia mentions that the gas has a “thickening agent” in it, which makes sense. What is the thickening agent for? To make any unburned fuel stick to the target? ---
**Author:** ![kopek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kopek/32/337_2.png) [@kopek](https://boards.straightdope.com/u/kopek)\ **Post date:** [October 17, 2014, 2:59pm UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/8 "2014-10-17T14:59:31Z")
> [@AClockworkMelon](#): > > Edit: Wikipedia mentions that the gas has a “thickening agent” in it, which makes sense. The term can also be “jellied” - we used to do a home-made version by taking 100 octane and dissolving styrofoam in it to saturation. ---
**Author:** ![kopek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kopek/32/337_2.png) [@kopek](https://boards.straightdope.com/u/kopek)\ **Post date:** [October 17, 2014, 3:01pm UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/9 "2014-10-17T15:01:17Z")
> [@Really\_Not\_All\_That\_Bright](#): > > What is the thickening agent for? To make any unburned fuel stick to the target? More to make it burn longer by providing both a flamible and a fuel. Like adding fat and wax to a cotton string to make a candle. ---
**Author:** ![Ale](https://avatars.discourse-cdn.com/v4/letter/a/f19dbf/32.png) [@Ale](https://boards.straightdope.com/u/Ale)\ **Post date:** [October 17, 2014, 4:15pm UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/10 "2014-10-17T16:15:43Z")
> [@Really\_Not\_All\_That\_Bright](#): > > What is the thickening agent for? To make any unburned fuel stick to the target? That and to keep the stream from dispersing, if not you’d end up with a fireball not far from the nozzle, good for show, not so good to do bunker BBQ. ---
**Author:** ![The\_Second\_Stone](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@The\_Second\_Stone](https://boards.straightdope.com/u/The_Second_Stone)\ **Post date:** [October 17, 2014, 4:26pm UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/11 "2014-10-17T16:26:46Z")
> [@kopek](#): > > The term can also be “jellied” - we used to do a home-made version by taking 100 octane and dissolving styrofoam in it to saturation. Sounds like a troubled childhood. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [October 17, 2014, 5:11pm UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/12 "2014-10-17T17:11:17Z")
> [@The\_Second\_Stone](#): > > Sounds like a troubled childhood. Or a fun childhood. We had a mixture of sunscreen, lighter-fluid, and something else that we would create a river with in a trench dug in the ground. We would build bridges and put army men in the river and on the bridges, then set it aflame.😃 ---
**Author:** ![The\_Second\_Stone](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@The\_Second\_Stone](https://boards.straightdope.com/u/The_Second_Stone)\ **Post date:** [October 17, 2014, 5:23pm UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/13 "2014-10-17T17:23:33Z")
And Memorial Day is a remembrance for those “siblings in arms” that didn’t make it? ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [October 17, 2014, 6:13pm UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/14 "2014-10-17T18:13:04Z")
> [@The\_Second\_Stone](#): > > And Memorial Day is a remembrance for those “siblings in arms” that didn’t make it? 😃 I don’t remember ever getting injured burning army men. Sooty, sure, but no loss of limbs or serious burns. ---
**Author:** ![Gray\_Ghost](https://avatars.discourse-cdn.com/v4/letter/g/c0e974/32.png) [@Gray\_Ghost](https://boards.straightdope.com/u/Gray_Ghost)\ **Post date:** [October 17, 2014, 6:43pm UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/15 "2014-10-17T18:43:27Z")
> [@The\_Second\_Stone](#): > > And Memorial Day is a remembrance for those “siblings in arms” that didn’t make it? > [@kayaker](#): > > 😃 I don’t remember ever getting injured burning army men. Sooty, sure, but no loss of limbs or serious burns. Shhhh. Don’t tell him about [tannerite](http://en.wikipedia.org/wiki/Tannerite). Sounds like fun, **kayaker**. We got the old wives’ tales growing up, but weren’t allowed to try and put them into practice. ---
**Author:** ![Bozuit](https://avatars.discourse-cdn.com/v4/letter/b/edb3f5/32.png) [@Bozuit](https://boards.straightdope.com/u/Bozuit)\ **Post date:** [October 17, 2014, 7:00pm UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/16 "2014-10-17T19:00:07Z")
> [@kopek](#): > > The term can also be “jellied” - we used to do a home-made version by taking 100 octane and dissolving styrofoam in it to saturation. Did your creation smell good in the mornings? ---
**Author:** ![UncleRojelio](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/unclerojelio/32/3160_2.png) [@UncleRojelio](https://boards.straightdope.com/u/UncleRojelio)\ **Post date:** [October 17, 2014, 7:04pm UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/17 "2014-10-17T19:04:19Z")
> [@kayaker](#): > > 😃 I don’t remember ever getting injured burning army men. Sooty, sure, but no loss of limbs or serious burns. If I had a nickel for every time I singed my eyebrows and/or arm hair off … ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [October 18, 2014, 8:48pm UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/18 "2014-10-18T20:48:20Z")
> [@JKilez](#): > > There was another propulsion method: > > I have seen flamethrowers that were powered by (what looked to be) 12 gauge shotgun shells. I think you are talking about Dragon’s Breath. These are 12ga incendiary rounds that spray fire for a couple seconds. They are not at all as effective as an actual flame thrower. > **[Dragon's Breath](https://en.wikipedia.org/wiki/Dragon's_breath)** > > Dragon's breath comes from mythology, as used to describe the ability of dragons to emit fire from their mouth. > Dragon's Breath, Dragon's breath, dragon breath or dragonbreath may also refer to: ---
**Author:** ![handsomeharry](https://avatars.discourse-cdn.com/v4/letter/h/e9c0ed/32.png) [@handsomeharry](https://boards.straightdope.com/u/handsomeharry)\ **Post date:** [October 19, 2014, 3:17am UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/19 "2014-10-19T03:17:47Z")
> [@UncleRojelio](#): > > If I had a nickel for every time I singed my eyebrows and/or arm hair off … Same here. Never did so by accident, tho. ---
**Author:** ![Urbanredneck](https://avatars.discourse-cdn.com/v4/letter/u/ea5d25/32.png) [@Urbanredneck](https://boards.straightdope.com/u/Urbanredneck)\ **Post date:** [October 19, 2014, 4:59am UTC](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568/20 "2014-10-19T04:59:37Z")
Does the US Army still field a flame thrower? I thought they were discontinued in the 90’s. [Next page](https://boards.straightdope.com/t/what-is-the-propellant-in-a-flamethrower/701568.md?page=2)