I am looking for a good type of fuel for a flamethrower similar to this design. <a href="http://people.howstuffworks.com/flamethrower2.htm" target="_blank">web page</a> (see the flash diagram about half-way down the page)

I am pretty sure that diesel fuel was used in WWII, but this model appears to be a vietnam model, which would have used napalm. I have seen many different posts on the forums about different ways to make napalm, but I don't think that anyone is thinking about the fact that different types of napalm have different uses. Does anyone know the chemical composition of military napalm meant to be used in flamethrowers? It must be thinner than the the gasoline/polystyrene mixture, which has the consistency of honey. I also doubt that the military used soap in their napalm. It doesn't seem complicated enough <img border="0" title="" alt="[Wink]" src="wink.gif" /> .

Thanks for helping me out, and please don't ban me for starting a new thread on my first post. I didn't see any posts that were closely related to this, except maybe the flamethrower one...and that focused more on flamethrower designs that used gasoline and kerosene.

i won't lock this despite you breaking a VERY important rule just don't do it again. this topic seems credible and thought out so you're let off.
as i replied in the flame thrower topic i'd guess a 50/50 mix of petrol and engine oil should make a decent fuel. reasonably long burning, hot burning, and pumpable.

The "Flammoel" (flame oil) the germans used in their flame-throwers during the WW2
was also a mix of 50% gasoline and 50% motor oil.

I bet a liquid fuel rather than a gelled one will be easier to work with in improvised flamethrowers. I'm thinking specifically in the nozzle/speed-of-ejection area which correlates to range.

The honey like military napalm thins under the shear strain of being forced through the constriction of a nozzle, so it becomes much easier to spray, though it instantly rethickens once it's out of the nozzle.

Read the SIPRI IW PDF.

has anybody seen those fuel gel refills for chaffing dishes and sterno type heateing canisters. i wonder how well this would suit your purposes. also on a similar note does anybody know what was in greek fire?

To bring this back to the topic, military napalm is a mixture of petrol (pure octane I would guess, but not shure), napthalic acid, and polystyrene. I italicise polystyrene because there is much confusion about this. Polystyrene and styrofoam are two different substances. However, what most people call styrofoam (or at least what people call styrofoam in america), is actually polystyrene. Styrofoam was a substance manafactured by some chemical company a while ago that never took off and found no commercial use. So the K3wLzzz arent all that far off when they make 'napalm' by shoving a block of polystyrene in some petrol. Does anyone know what napthalic acid is, chemically? If its a Lowry-Bronstein acid, then its probably just two fused benzene rings with an H+ coming off 'em. If its a Lewis acid, though, it could be something more complicated.
I agree with what has been said, napalm is much too thick for anything bar a professional/military flamethrower. For the crudeley improvised ones, just use motor oil/octane 50/50. I have a contraption bareley worth the title of a flamethrower that I built for clearing land of small shrubs/grass out of a fertilizer sprayer. It would have no value as a weapon in combat, but works wonders against weeds!

<small>[ March 05, 2003, 02:10 AM: Message edited by: metafractal ]</small>

Rjche (I think, it could have been BadSeeD) once said that military napalm is 50% polystyrene, 25% Benzene, and 25% gasoline. I've also read this in a few other places.

Experimentation is the key to what your looking for, nozzle size, psi, and flowrates all effect the distance of the napalm. Of course its alot simpler to just keep playing around with different formulas, instead of adjusting the gun. There is a massive list of thickening agents in the 'Improvised Munitions Manual', which can be found in the Poor Mans James Bond #1.

There is also a book by Ragnar Benson that might help you, 'Dragons Breath' its either on the FTP or online.

I have read something about military napalm containing white phosphorous to make it burn hotter and be extemely dificult to put out.

<small>[ March 05, 2003, 05:26 AM: Message edited by: xyz ]</small>

"They found that mixing an aluminum soap powder of naphthene and palmitate (hence na-palm), also known as napthenic and palmitic acids, with gasoline produced a brownish sticky syrup that burned more slowly than raw gasoline, and hence was much more effective at igniting one's target. The napalm was mixed in varying concentrations of 6% (for flame throwers) and 12-15% for bombs mixed on site (for use in perimeter defense)."
I found this about american WW2 napalm.Does anyone know the exact recipe?

So does that mean that WWII napalm is different from the more modern, Vietnam-age napalm? If so, what is the difference?

Well, as far as flamethrower fuels go, I'd say that good ol' 50/50 mix of Gasoline and Diesel (or kerosene) works quite well. The gasoline ensures that it ignites immediately, whilst the kerosene or diesel allows it to burn for a much longer time when it hits the target.

As soon as it gets warm enough to be outside, I'm gonna be testing a large number of different flamethrower fuels and keep you all updated.

i recently experimented with some napalm. i used polystyrene, gasoline(87octane), acetone, and a bit of kerosene. depending on how much acetone you add to the mix you get varying thicknesses of napalm. mine was similar to liquid soap/watered down syrup. it poured very easily and stuck to everything. also when i filled my supersoaker up it had a range of~20 feet. it was ignited with an 'aim and flame' lighter. this particular mix burns on water.

i plan on eventually making a proper flamthrower since the plastic will eventually melt/soften from teh acetone/benzene

i thought that vietnam era napalm was 46% polystyrene, 33%gas and 21%benzene. (i might have gas/benzen mixed up)

I believe that orignal napalm was a powder, consisting of "a coprecipitated aluminum soap from naphthenic acids and the fatty acids of coconut oil developed early in 1942 for the preparation of gasoline advertisement." This powder was then mixed with fuel to form a sticky thick highly inflammable liquid. I also remember reading some where that napalm bombs would suck the oxygen out of the air, increasing the amount of CO to lethal amounts (around 20%).

-Ancalagon


for incendiary munitions."

that is quite possible but note that i said "I thought that vietnam era napalm.........."
has anybody in the forum made a flamethrower worth bragging about and is willing to share the plans?

I think the best flamethrower design is one that uses a fertilizer sprayer, they are made to handle fuels and such and the nozzle is adjustable. Mine shot like 15-20 feet with straight gasoline. I didn't really have an ignition system though, I just had a burning rag attached to the nozzle assembly with a copper wire. I think the best ignition system would be one of those little butane torches mounted somewhere on the handle and then the part where the flame comes out, take that off and mount it on the nozzle in an appropriate place to light the mixture. Then, get a long fuel line, hook that up, then do the same with the spark igniter, and presto you have an adjustable flame thrower that can be turned on and off right at your hand. Oh and both the mixture lighter and the mixture are easily refillable.

As per Ragnar Benson's "Breath of the Dragon" military Napalm was gas, diesel and M-2 or M-4 alumagel that was a cream colored powder. Their use was dictated by the weather and humidity and depending on tempature ranges with in those two main ranges M-2 warmer, M-4 colder. He gives no specific chemical formula but most of the folks here in the forum are more chemical savvy than I and might have a better idea of it's nature. He go's on to explain, that he finds a 50/50 or 40/60 diesel and gas mix are desirable fuel mixtures in conjunction with the alumagel. Mr. Benson also suggests using a product called Sure-Fire made by Simplex Manufacturing Co. out of Portland Oregon. Again no chemical specifics just info of what and where to get it.

As in the Flamethrower thread I've been looking for info and I found a copy of "The Breath of the Dragon" is cost me an arm and a leg but it was worth it, also I found a guy who had all US flamer manuals on CD and I just got it in the mail the other day.

Flamethrowers are still legal in most areas although that might be changing with the fallout of Sep. 11th. I've heard of complete flamers going between 12-15k

I've been gathering parts based on this knowledge and pretty much have a rough idea of how it will work. I just found a gas tank and need to test it for it's pressure threshold, although the mechanics of the wand will take the most work and planning. I've got a couple of issues of American Survival Mag. that have articles about Flamers and their legallity. "Mail Call" on the history channel also had a flamethrower on it the other day and I'm going to buy the Episode just for added info, and because it was really cool showing it actually working. If all go's well I'll post some pictures here in the next year on my progress.

I remember reading somewhere that some of the military flame-throwers could shoot in excess of 80 feet. I wonder if anybody knows something of this. Also, is there a procedure to extract palmitic acids from coconuts, or would simple de-juicing work?


-Ancalagon

Is it really necessary to use what they used in Vietnam or WW2... Come on. All you need is a a way to thicken already flamable liquids. Your best bet would be oil; cheap and readily available.

Remember the KISS rule. No need to make things more complicated than they need to be.

Acetone and styrofoam...how hard is that? And that's pretty much what the military uses now too, so you don't want to fuck around with the old palmetic acid crap, which gave an applesauce-textered goo.

Just keep adding styrofoam to the gas till it's thick enough to spray, and you're all set. :)

i Have a flamethrower that uses MEK as a fuel. It's the perfect consistancy for spraying, and you can buy it in stores as fondue fuel. It's blue, and very flammable. The cool thing is, the flame is almost invisible! They wont know what hit em!

I know there are much simpler ways to make napalm than with the ol' coconut oil methods, but I am interested in the process that was used before. After all, people still by crossbows, swords, and blackpowder guns, all of which are rather outdated in accomplishing what they were designed to do.

-Ancalagon

Skean, what was your kerosene/gasoline ratio? Did the kerosene make a big difference?

By the way, were you in the military at one time, nbk? You seem to know alot about what the military uses. I was just curious.

i find that acetone/xylene or acetone/gasoline in a 50/50 mix with styro added gives a nice thin, sticky napalm.

Stir in some KNO3/Sugar and your set. ;)

I'm in the proccess of building a mini-flamethrower (possibly more details to come in improvied weapons), and I'm giving a lot of thought to what mixture I want to use for the napalm. Typically, I go for a gasoline/acetone/polystyrene mix, but I was thinking of using jellied petroleum instead of the polystyrene and also adding naptha. The problem, however, is that it is not very sticky, so I was wondering what I could add that would keep the mixture thin, but add to its, um, sticking power. I am considering using rubber cement.

-Ancalagon

I thought that vietnam era napalm was 46% polystyrene, 33%gas and 21%benzene. (i might have gas/benzen mixed up)


I remembering reading that in several places as well. I've made napalm a few types and have noticed that the viscosity changes with the grade of polystyrene you use. I used this generic white rough polystyrene once and it game out really thick, almost like a tough glue. Another time I used this blue, smooth insulation foam, which seemed the perfect consistency for spraying. It was thick but still liquidy enough to spray with. Ill try to find out what it was.

Does the acetone help the polystyrene to dissolve better in the petrol? It's just that when I tried mixing polystyrene and petrol, the polystyrene formed a very thick gel at the bottom of the petrol, but didn't properly mix.

In the end, I just used straight petrol with my weed burner, and consequently the range suffered as the stream of fuel dispersed. Plus, the pressure was under 12 Bar due to a leaky pressurization valve (the valve seals were not petrol resistant :( ).

http://img263.imageshack.us/img263/496/pilotlightnt4.th.jpg (http://img263.imageshack.us/my.php?image=pilotlightnt4.jpg) http://img180.imageshack.us/img180/8412/89424591bj0.th.jpg (http://img180.imageshack.us/my.php?image=89424591bj0.jpg) http://img175.imageshack.us/img175/8775/39237561yv7.th.jpg (http://img175.imageshack.us/my.php?image=39237561yv7.jpg) http://img175.imageshack.us/img175/3669/36904047vl1.th.jpg (http://img175.imageshack.us/my.php?image=36904047vl1.jpg)

I will probably unearth it during August/September to rebuild the valve with fuel resistant seals and try some thicker fuels.