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I find its a lot more fun to worry about how stuff can work. You know, imagination and all that.

Probably there are many different varieties of promethium, and they differ in purity and essence based on the distillation process. Kinda like crude oil which is black gunk but then you refine it to produce diesel, regular gas, jet fuel, space shuttle fuel, etc. So the promethium inside a refinery or a tank I suppose is high-grade, super combustible stuff, while promethium in a flamer tank has some kind of additive in it to make it safer to handle (i.e. you don't fart then spontaneously combust) and you need a pilot light to ignite the chemical reaction.

Well, that's my speculation anyway.

*high fives Rabidaskal* I can live with that explanation. (Makes me wonder about the fractionation process though)

rabidaskal wrote:Probably there are many different varieties of promethium, and they differ in purity and essence based on the distillation process. Kinda like crude oil which is black gunk but then you refine it to produce diesel, regular gas, jet fuel, space shuttle fuel, etc. So the promethium inside a refinery or a tank I suppose is high-grade, super combustible stuff, while promethium in a flamer tank has some kind of additive in it to make it safer to handle (i.e. you don't fart then spontaneously combust) and you need a pilot light to ignite the chemical reaction.

Well, that's my speculation anyway.

damn, im going to have nightmares about promethium farts now, thanks a lot

rabidaskal wrote:Probably there are many different varieties of promethium, and they differ in purity and essence based on the distillation process. Kinda like crude oil which is black gunk but then you refine it to produce diesel, regular gas, jet fuel, space shuttle fuel, etc. So the promethium inside a refinery or a tank I suppose is high-grade, super combustible stuff, while promethium in a flamer tank has some kind of additive in it to make it safer to handle (i.e. you don't fart then spontaneously combust) and you need a pilot light to ignite the chemical reaction.

Well, that's my speculation anyway.

I do believe this is the case. I think I recall reading in one of my BL novels that Vehicles use a more concentrated form of Promethium than that in Flamethrowers. Wouldn't suprise me at all if this is the case.

It is 40,000 years in the future. Perhaps they added a chemical to the prometheum so it needs to be ignited? Might make it a bit safer to lug around.

Nurglitch wrote:I'd go with the idea that the little pilot-light looking thing is actually an oxygen spritzer for low-oxygen environments.

maybe they just don't want to ignite an emperors weapon with xeno air so it holds air from terra

although I don't remember which one, IIRC in one of the Caiphis Cain novels ithere is a pretty good explanation of promethium and its varied uses, from fuel to manufacturing goods. Its like a super element that combines the properites of plastic fuel and fission. I'll check when I'm home. Its one of the new ones though I think not the oens in the omnibus.

Well pure potassium, sodium, and that the other metals in its group will react violently to water regardless of whether it is liquid water or just water vapor in the air, some of the elements lower down like caesium and rubidium will actually explode if they come in contact with enough water. So, if promethium has similar traits then it would actually ignite on contact with the water vapor in the air. Also whoever said something about the flame nozzle being there for planets without an atmosphere, fire only works when there's oxygen to be used in the reaction, so no atmosphere = no flamers.

Edit:grammer... twice

Not quite true, there are substances that hold the oxygen they require chemically bound into their structure. Thermite is the best example, once you've ignited it you can pour dirt on it, toss it in water, shove it in a vacuum and it will still keep burning.

I understand you're using thermite as an example, and there are other substances with the same trait, but i'm having problems seeing a substance like that being useful as a flamethrower in a vacuum, i'm not saying it wouldn't burn, but once it exhausts its oxygen it would just go out, due to a lack of oxygen to ignite the target, which doesn't seem horribly useful. On the other hand i am aware of the sheer amount of heat you can get from burning thermite, but if it is used in space wouldn't that just cause the heat to dissipate even faster reducing the usefulness of a flamer.

No, no. What she's saying is that the reaction of thermite releases oxygen on a molecular scale. (I forget the ratios) but its chemically bound. As in you'll always have enough oxygen as long as you have enough thermite.

When you run out of fuel, the flame goes out. The same can be said of any flame thrower.

Over the long term space is very good at sapping heat, but over the short term it's actually pretty horrible, vacuum is an excellent insulator. Of the three methods of heat transfer (conduction, convection and radiation) only radiation works and it's not very fast on that scale.

A much more significant issue about using flamers in space is that you have super heated substance coming out the barrel. This is basically a chemical rocket. And like all rockets, conservation of momentum will send you shooting back in the opposite direction.

Depending on the forces involved, the resistance that would send you rocketing backwards would be much more than a flamer would produce. Assuming they work in a similar fasion as the WW2 flamethrowers which if understand them right was in a worst case scenario like holding on to a hose turned up high, not the explosive force of rocket feul. Also i was not aware that vacuum was a good insulator, although thinking on it it does occur to me that there wouldn't be atmosphere to have heat transfered to and even with it it can take a long time for things to cool down. I could actually see a flamer being viable in a vacuum now as there would not be wind or shockwaves in the air causing aiming it to be difficult and the heat taking longer to dissipate.

vaccuum = no mass. No mass = no mass transportation. No mass transportation = no conduction or convection.

radiation requires a d4 dissapation (meaning you have ^4 path of heat decomposition.)

As for not rocketing backwards.... THERE IS NO FRICTION IN SPACE. Therefore sneezing has you moving. Something with fuel would have you moving MORE.

There is a reason why Thermos flasks are also called vacuum flasks.

In Ghaunt's Ghosts: Traitor General(just read it not to long ago) promethium is smelled in the marshes, the "untill". It bubbles up in the water and is even lit later on to blow up the area, so from that i would think the natural state is a gas like propane.


I think the character Brostin makes a reference to raw Prom. as well(but this is just a book)

at thermite, you practically look at the stuff and it catches fire

lemon detective wrote: at thermite, you practically look at the stuff and it catches fire

You've ever actually used the stuff? Lighting it is a pain. Dramatic once you've got it going but you need a magnesium strip or another high temperature ignition source to trigger it.

I know that this is off topic, but IIRC U.S. forces used thermite grenades to sabatoge artillary peices in WWII, thermite burning is pretty awsome though.

Er, I find it rather likely that there is no intentional relation between 40k Promethium and the element of the same name.

I think the people at GW decided they'd like something cooler sounding than 'fuel' and named it after Prometheus, the Titan that stole fire from Zeus and gave it to mortals in Greek Mythology.