Make Charcoal.

[Total_CDRW]

What exactly is in charcoal that makes it so nice in BP? The Carbon... I have no charcoal, but plenty of pinecones... can i extract charcoal from them? I've been fooling around with an old 5 gallon pail that has no bottom, and have been trying to burn pinecones to a point where they're all blackened and mostly glowing embers, is this a state i want the pinecones for charcoal? I got a cup full of pinecone remains, are they worth throwing into a grinder and mashingup for charcoal?

[yt2095]

the carbon is used as fuel for the oxygen content of the KNO3 to consume.
pinecones would be lousey to use, too much resin, use a low ash content wood, rose or willow work great.

i`ve got a feeling you won`t be around here long enuff to read many more replies to your question!

1) did you read the FAQ rules section?
2) did you search the forum for answers to your question 1`st?

i think not on both counts :(

since it`s the water cool section, you MAY get away with it... Here`s a Tip: if ya see anyone called NBK heading your way, don`t even bother to run!

[Kriegsminister]

Yeah it would be a great idea to search BEFORE you post a question...

However, this page (http://userpages.prexar.com/dwilliamsmaine/charcoal/charcoal.html) might be interesting.

[Sonny Jim]

At least he posted the question in the water cooler rather than in one of the other forums. That, at least, shows he was not disregarding the rules.

Total_CDRW, I think pinecones could work, although willow is supposedly the superior wood to use when making charcoal for pyrotechnics. I think you are preparing it wrong though.

In my experience, glowing embers are bad news. The charcoal turns to ash if it is allowed to burn like this. The way to stop this from happening is to heat the wood without allowing oxygen to get to it. I do this by placing the wood in an old pan with a lid on it, and heating it over the cooker.

After a while, lots of smoke will come out of the pan, through the gap between the lid and the pan. This is a problem if working indoors, unless you have one of those extractor fans above the cooker. Anyway, keep heating the wood, but leave the lid on. If any flames lick out of the pan, stop heating and resume later if nescessary. You can tell if the charcoal is ready by trying to snap it. It should be very brittle, and black all way through. If it is not, heat some more.

One last thing. You should leave the lid on the pan even while the charcoal is cooling. If you do not, and the charcoal is still very hot, it will begin to glow red and turn to ash. Only when the pan has cooled should you remove the lid.

[vulture]

His question is in the watercooler so he's going to get away with it, if you like it or not.
Furthermore he does not show any signs of total stupidity or ignorance.

BTW, noobies should be careful reading other noobies their rights...

[Tuatara]

Actually, I think his question has merit. I've seen many sites which say charcoal made from this wood is better than that, but not why. Where's the chemical rationale? Why does graphite perform so poorly? Why can't you use coal dust, or crushed coke, or soot? Its all basically carbon after all (ok, I know they are different structures - I'm not completely stupid).

[0EZ0]

There are a few reasons why some types of charcoal are more favourable than others. Firstly lighter and more fluffy/porous woods are more widely used than hardwoods because there is a higher potential surface area for the oxidiser to work with. Sometimes you might hear in pyro formulas to wet mixtures and screen them to provide the fuel and oxidiser more intamacy, thus raising the burn right to a higher level. With lighter porous charcoal the in this process the KNO3 deposits itself deep within each tiny grain of charcoal. Dense hardwoods do not really posess this ability to combine with the oxidiser so intimately.

The reason why pure carbon or graphite are not used primarily as a fuel in Black Powder is because they do not posess the volitile hydrocarbons and other little gems that make organic charcoal so good as a BP fuel. You have to realise that the KNO3 is not just oxising the charcoal into CO2, there are other compounds present in the charcoal grains that are decomposing as well. That is why it is seen that pure carbon BP mixtures are so worthless with the exception of a few priming formulas that use lampblack (pure carbon from incomplete combustion of propane).

Have you ever wondered why there is so much folklore behind Black Powder and Pyrotechnics? My guess would be because there are many variables to experiment with to produce a quality powder that has the highest perfomance possible. Eg. charcoals can vary quite widely and effect the perfomance of your bp, or the density of each component can effect the final burn rate. Different manufacturing techniques also come into play.
So simply using stoichiometric ratios for BP will work, but not have that edge that other formulations do that have come about with experimenting. Fine tuning of ratios is needed to get the highest performance out of your BP.

If you ask whether you can use hardwood charcoal or lumpwood for BP, yes you can get away with it. But unless you really experiment with different charcoals and production methods, you can't really have one answer for what is best. For example if you are a bit lazy and can't be bothered preparing your own charcoal from porous woods, you can still get a quality product from lumpwood charcoal if you mill your bp thoroughly. But if you want to use hardwood charcoal and mix each ingredient together manually or use the CIA method, you will most likely get poor results compared to using a porous charcoal. Different processes yield different results.

As a tried to write this up quickly, there are probably a few inaccurate points. Hope it helps a few of you though.

Regards

[yt2095]

the lumpwood BBQ charcoal is all i use myself and it does give respectable results.
but be selective when choosing the lumps to break up, idealy you want the peices with the largest volume but lowest mass. that`ll give a relatively clear indication of the ash content, the more dense the peices the less usefull is it.

wrap those sellected lumps in several layers of newspaper and smash then up with a hammer outside untill they`re usable sizes to put into a mortar/pestle. then grind it up as finely as possible wear a dust mask! the sort you can buy for pennys at a hardware store usualy in the section where they sell sanding equipment, it`ll save alot of black tissue paper when you blow your nose later :)

there`s sections on here about making and using ball mills too, tho i stick to the old arm building technique and do it by hand (making powdered charcoal that is) :)

when i`ve mixed thet with my KNO3 and Sulpher, i add a tiny drop of water to the grean meal powder untill it becomes a breadcrumb consistency, wrap that in cling film and put between 2 steel plates, then add as much weight as i can ontop of this and leave it for a few days.
after you take it out and leave to dry it`ll be quite hard and have a hollow ceramic type of sound when tapped, break this up until it will all pass through a fine mesh seive (i use a tea strainer).
this gives me a BP of quite a decent quality, and very useable.

all the best.

[Sonny Jim]

I'm sure I read that BBQ charcoal is contaminated with crap like mud also. Maybe you should try making your own charcoal and comparing the results yeilded by BBQ and home made charcoal? Could be interesting!

[vulture]

Why don't you try it yourself? The reason why people get pissed at newbies is because they always ask others to test stuff for them.

[Sonny Jim]

I was merely suggesting an interesting idea. It's not as if I was ordering him to do it or else or being rude about it. The reason I ask him is that:

1. Maybe he thinks it's a good idea too that he hadn't thought of, that he now might like to try.

2. As I would guess he already has a load of BBQ charcoal, he could carry the experiment out easier than me, who would have to go and buy a huge bag of BBQ charcoal I don't need the vast majority of.

I think there comes a point when 'pissing people off' becomes just too easy, and it is no longer the fault of the 'newbie', but the other people who get annoyed by such insignificant things. Whoever is so bothered by a person suggesting a little experiment be conducted may officially call themselves sad.

[kingspaz]

lets just leave it at that before we have to reach for our asbestos suits. mine has holes in it from the last flame war :rolleyes:

[Anthony]

lumpwood charcoal shouldn't have any mud/clay in it, as it is just that - lumps of wood. Charcoal Briquettes on the other hand do have a lot of clay in them, I suspect they are pressed from charcoal/coal dust with the clay as a binder.

[Total_CDRW]

i've been away...

but, i'm gona try this pinecone charcoal, since BBQ charcoal works like crap... and how can i mill BP with an old rocktumbler? will lead fishing weights work? or golfballs? i got a food processor, will that work?

i'll try the pinecones in a paint can over some flame... i got plenty of Pine lumber odd chunks? should they be cut small and "smoked"

PS: i tried searching for "Charcoal Making" and i get a load of junk... mabe i'm using the wrong words... i though why not just ask the question... using the words "Charcoal Making" and see what i get. Mabe some other noobies can get easier answers if i ask the question with the right words-making it easier to search for.

[Skean Dhu]

how i make charcoal in small batches. it consists of a paint can with holes poked in the bottom(must be bottom only putting holes anywhere else will allow fresh air in) then i set it on a couple bircks and build a fire underneath it. after a while the wood inside will start to char and you will see flames coming out of the holes. this is perfectly normal/ok. if flames are coming out of the top your batch will be ashes and useless for this activity. then i let the fire die away and leave the can to cool over night. the next morning i open it to find wonderous charcoal.

P.S. if you don't have anempty paint can lowes sells them for some capitalist price

[zaibatsu]

Search for the site by Dan Williams, he has a useful procedure for making charcoal. I don't think your process sounds right Skean Dhu, you should put holes in the top. If I'm right, you want to indirectly heat it, rather than have it make contact with the flames. With holes punched in the top of the tin, you should be getting smoke coming out the top, but not flames. But, whatever works for you.

[Anthony]

Second that, ventilation in top has always worked for me.

[kingspaz]

i find sometimes however that the smoke can catch fire (CO burning i guess). so you could also have flames coming from the top :)

[Skean Dhu]

the holes on the bottom allow the volitile gasses being driven off to serve as its own fuel. once you get all the water vapor driven off, it becomes a self-sustaning(sp?) charcoal cooker, and no additional wood needs to be supplied . also when all the volitile gasses have been driven off the flames die away and your charcoal will be done. this takes out the guesswork and supervision that would otherwise be needed. but hey as you said before whatever works for you

you are correct zaibatzu you don't want direct heating(in this case although there are methods that do use direct contact) but the pressure created from expanding gasses and lack of oxygen in the container prevents the flames from doing anything more than heating the tin

what i do is a scaled version of what this guy does http://64.176.180.203/charcoalretort.htm
on the 8th picture down you can see the gasses jetting out if you look closely

[Total_CDRW]

K, somehow this works okay... i'll scrounge up a paint can somewhere.... but i just burned some pinecones and pocked the glowy "cores" of the pinecones out of the fire (which was in an old 5 gallon paint can) washed the ash off of them, and used my morter to mash them up into dust, then filtered it was a sheetrock sander, which is kinda like screen with a finer mesh then the stuff you find on people's patios. That seem to get it pretty fine, but i'm not sure if the quality is too great, but i know it's better than Broquets...

Got ta go, another annoying florida lightning storm is brewing... oh nm, i got battery backup...

Anyways, i am having trouble with keeping sulfur from creating lumps... and the Potassium Nitrate lumps too a bit. The best way i can mill right now is with a morter, will that produce semi-good quality BP?

What residue if any should your black power leave? cus mine leaves charcoal specs all around where the BP was burned. I only got a cheepo 16oz-500gram Walmart scale dont know how precise it is, does the 10% sulfur, 15% charcoal, 75% Potassium nitrate have to be exact-exact or just cheep walmart scale exact?

[Total_CDRW]

It seems every link place in this forum goes nowhere... and they're all IPs why not domains?

[yt2095]

Total,

In my experience, the charcoal traces show your nearly there! :)
the powder should look a dark green color hence the name "greenmeal"
this still isn`t BP yet tho.
add another percent of total weight of KNO3.
then add a little water to your green meal and press it into pucks (it makes the mix more intimate) the more pressure you can apply to your green meal the better BP you`ll get.
let the pucks dry in the sun, then in a bucket with sand bags around it, break them up with a baseball bat or something (anything heavy and non metal)
then pass your BP through a seive to grade it.
i think you`ll find you`ll be quite impressed and it was worth the effort :)

all the best.

[Total_CDRW]

ACK! Dubble Post, Read Below

[Total_CDRW]

Ah, Kool...
Leme Claifry, My Mixture seems to work okay, better than the brouquet charcoal. I think i'll mix up another 100 grams... But what is the green mix... i dont think my "Mixture" is green... should it be, I mixed Charcoal, Sulfur, and Potassium nitrate (in the correct 10:15:75 porportions) used my morter to mash it together, then wet it to a paste consistancy placed it on a styrofoam platter to dry (the last 3 days). And have mashed up chunks of this to make what i though was BP.

So this is green mix? If so, you suggest to add %1 more Potassium nitrate then ok, but is this green mix?

BTW, what can i use as a siv... if i get a hold of my camera (probly tomorrow), i'll give ya a picture of what i'm using, but its a little finer than window screen, and since i'm using a morter to mash it up, the particles arent that chunky or big.

[yt2095]

it`s called green meal because of it`s color, it`s mora a grey green really (the sulpher does it).
wetting it and drying it will still be green meal.
you need to compress it (it`s done to over ton of pressure commercialy!)
if you can do that will several hundred pound or more, you`ll be alot closer to real BP.
i still wouldn`t use it in my favorite riffle, but it`ll make very respectable rockets, lifting charges, COB`s etc...
the reason you`ll need an extra percent (roughly) is that the compression absorbs the nitre into the charcoal, so your mix will seem to be fine as green meal, but a bit lean as BP.
your screendoor mesh will do just fine :)
briquette charcoal (if you can call it that) would be crap! lumpwood`s your best bet as posted way above, if you can find someone that has rose bushes growing, ask them for the off cuts next time they prune them, their unlikely to say NO as you`ll be doing them a favour :)

all the best :)

[Total_CDRW]

I guess it does look green after you hit yourself in the head with a brick a few times... j/k but anyways, I made a fairly small quantity of green meal then, how can i estimate/guesstimate how much KNO3 i need since it is such a small amount (15grams).

[yt2095]

do a simple burn test, i do mine in a stainless steel tray, add KNO3 in small amounts and test each time until it leaves tiny white balls of unreacted material, that will say Oxidiser rich.
THEN, damp your mix and press it.
remmember the more you can press it the better!!!
a PASSIVE weight tho, not pounding with a hammer :)

[Total_CDRW]

it tis drying!... i just decided to throw a bit of KNO3 in... if it's not enough, cant i just add more, and do again? I can see the little 'pucks' look different than the green meal... i think a diferent color... mabe my eyes are messed up from the sun, but they do look different than the green mix. I pressed it with the back end of a screw driver, and pressed it with a rolling pin... hope it works!

How long should it take to dry completely? Cus sometimes the center is still moist in my mixes... is that because it's too thick?

[yt2095]

in all honesty, with a rolling pin and/or "back end of a screwdriver" you`ll make only a marginal difference at best.
it needs considerable pressure over a length of time too (over night is good!)
lol, even between 2 peices of steel and under the leg of your bed or heaviest furniture would make a significantly better mix than your above methods, the color will change sure, it`s becoming a more intimate mix, but you need this to be almost at a molecular scale (in an ideal world).
you may take the puck out whilst still damp, and let it dry as a whole. it doesn`t have to dry under pressure :)

in fact the proper way hardly ever used any damping of the mix at all, it was put between leather sheets in layers and pressed for days with a good ton or 2 then allowed to dry, this was repeated until the mix was as good as molecularly intimate as was possible in those days.
but for our sakes, read above at my second posting, and it has the instruktions there.

[Total_CDRW]

Under 5 bricks, sandwiched between too sheets of aluminum foil... 5 aprox. pounds per brick... that should do it.

[Skean Dhu]

i think the term ' green meal' refers to its lack of ageing/curing(like wood, err that didn't really prove my point ) rather than some barely noticable tint. also you could use green meal in pyrotechnics, its just for reloading ammo you want grains, and it does mix better .

if you want toget real fancy you could make a hydrolic(sp?) press from a hydrolic car jack(i've seen em at wal*mart and Kmart for under $50us,they come in multi ton sizes) and some scrap iron. but you probably need to know how to weld. btu thats only if your gonna go hardcore black powder production. or maybe a nice sized bench vice.

[vulture]

After recristallizing my BP from water or water/acetone it's no longer green and the burnrate increases significantly. Odd that it doesn't work for you guys.

[yt2095]

What Vulture says is quite right, it will make the mix burnrate much faster.
the charcoal you use, no mater HOW small your mesh, will still be full of holes and cavitys(sp?) that your S and KNO3 will not be able to get into, effectively voids!

the mixing with water will fill SOME 50% or more of these voids.

pressing at great preasure will ensure almost complete intimacy of your mix :)

Skean Dhu:
sorry no, your quite wrong. it`s called green meal for the above stated reasons. BP doesn`t need to CURE except in the method also mentioned above. and AGING does nothing to enhance BP whatsoever. as for fancy, the use of a car jack is used in many home brew BP manufactures. i used to use one myself :D
green meal as a lifting charge is at best weak, if you DON`T want to press it, then use vultures method, is DOES improve it!
we have NO interest in giving false info.

all the best anyway :)

[Total_CDRW]

How can i tell if i have good BP? i mean i didnt know BP had so many stages... almost hard at least the first time to make it, until you get a system down, if i had know this, i wouldnt have bought 10 lbs of P. Nitrate 5 of Sulfur and Crushed my own Charcoal. :rolleyes: oh well...

I've found using an old Frying pan over a rubbing alcohol flame, and mixing 3 parts Potassium Nitrate, 2 parts Sugar until it melts is alot easier and seems more fun, but can i use the stuff in rockets? My 'Real' dream.:D

[yt2095]

sure you can,
a quick search on here will reveal 100`s of ways to make sugar or candy rockets.
i`m surprised you hadn`t already done that?

[Total_CDRW]

Whoops... i'll still use the green mix/BP stuff for something entertaining... but i find that the sugar stuff is slow burning and you can run around with a glob of it on a stick making smoke messages :-P

[Skean Dhu]

i know that ageing BP has no effects on its preformance, and when i said curing i meant by pressing it into 'pucks' its just i was trying too hard to make an analogy and didn't use the right words.

just outta curiosity why wouldn't it work as a lift charge, i mean if its really well ballmilled wouldn't it work fairly well? i understand that the grains will work better because of surface area and better intamacey(sp?)

also for in rockets i wouldn't think it would matter because your going to press it anyways so it dosen't pull a challenger on you.
can't wait till i have enough $ to order a scale from pyrotech. does anyone know of one cheaper but still of high quality?

[yt2095]

you said it exactly, it`s all about surface area, even if ball milled when in your mortar, it may as well be a solid lump.
inversely that would be that exact desired effect in a rocket mix :)
as for scales, i use a pair of cheap drug scales i bought on a market stall for about £3.50.
the sort junkies use to weigh out their coke or whatever, it works great for me, it`l even do as low as miligrams.

[Anthony]

I can assure you that weighing up the components (making green meal) and throwing them into a ballmill will give decent black powder.

At this point (after milling, before pressing/graining) it is known as "Meal D". Mine was always a dark grey in colour and messy as shit to work with, but worked for everything from salutes to rocket motors to lift charges.

My attempts at corning weren't very sucessful and the Meal D was good enough for what I wanted so I never bothered.

I'm not sure that corning necessarily increases burn rate. In theory it should reduce it, as typically finer powders increase flame propagation. But then you have the increased intimacy from the pressing. So why not press and mill back to a fine powder?

I suspect that the main reason is to make the stuff less messy to handle/easier to pour and to provide a more stable burn rate. That and the glazing of the grains increasing water resistance.

Could be wrong though.

[yt2095]

the way i picture is like this.
imagine a very fine powder so fine infact that it will act almost as a solid, and upon ignition is almost forced to burn from 1 side to the other but only as fast as the powder itself will deflagrate.
in a granular mix (same composition) it will allow inter granular flame propogationso the flame could be on the other side of the container before the 1`st granule has even finished burning. in effect the specific impulse of the powder is increased. the polishing helps with water barrier sure an added bonus :)
and yeah it makes it nicer to handle and use.
of course i picure the above in a type of slow motion. i have ground up proper BP and for rockets it`s a great mix! whereas the granular form would probably explode like a cheap fire cracker.

[Total_CDRW]

I got a Rock Tumbler, a couple yogurt cups, and some marbles, will the marbles spark, if i try to use them to mill BP? I was thinking i can take the Yogurt cups and place my Green Meal and marbles to mill, i'd rather not have a *broken rock tumbler*...:D

Edit: the words 'house fire' were removed and replaced with 'broken rock tumbler'

[yt2095]

to be completely honest, i can`t answer that other than from the standpoint of personal opinion and that of other researchers.
that being said, glass on glass should not create any significant problems for you, and in yogurts pots, it`s more likely to go Whuuump than BOOM!.
again... having said that, you would be phukin MENTAL! to ball mill in your house!!!!
what on earth are you thinking!????

if your looking for permission to say that it`s OK to ball mill in yogurt pots with marbles IN YOUR HOUSE, then yer not gunna get it here!

so....

1) yes it will work
2) it may take a time but worth it
3) the best way to avoid ANY "house" accidents is to keep it OUT of your house :)
3.5) (use someone elses) :)

for the record, i didn`t type point #3.5 HONEST!

[kingspaz]

Total_CDRW, why not find out yourself?
in a dark room hit som together really hard.

yt2095, fuck is spelt with an F not ph.

[yt2095]

no $h!t sherlock!

phact is, i don`t like to swear in text, on the off the chance there maybe kids on my chan, it`s a habit i`ve goten into, and i don`t think it`s a bad one.
and WHAT it has to do with E&W beats the hell outa me?
are there perhaps not more IMPORTANT things to complain about???
either way, i think your being just a little picky here!

the point in my post is valid.

a problem with that?,,, i`m all ears

[Total_CDRW]

Have i gotten to the point where i should place all my other comments into the Pyrotechnics area of the forum under a thread with the same name??...

now i just gotta find a place at least 10 feet away from my house... and it rains alot in FL so i cant just place it on the ground... I have sheds, but they're filled with other stuff... stuff i'd rather not have burned (like furnature, paint cans, and a lawn mower)... um.... House=Bad... Outside=Kinda-Bad...

anyways, i cant seem to find many marbles under my bed... only one, and a hot-rock (you know, those seeds that you scrape across concrete really fast, and then place the nut on the closest person to you's arm, and listen to them scream :D ) can i use BB gun pellets, a marble, and a golf ball? would they work better together, or just one?

[Anthony]

The problem is that replacing "F"s with "Ph" is kewl/leetspeak, like "Bomz" etc etc

Also we like our spelling and grammar here :) Makes the place look tidy and intelligent.

If the situation calls for a dramatic response such as swearing, then there's little point censoring it, this isn't a kiddies play group!

Although the censorship worth of "phuck" is questionable, everyone - including 6 year olds know what you mean, if they don't and try to pronounce it, it still comes out as "fuck", so pointless really.

[Total_CDRW]

I've read the rules... is that last comment supposed to point at yt2095?:rolleyes:

[kingspaz]

Total_CDRW, Anthony's post is not aimed at you.

have you checked your local fishing shop? they will likely stock a type of fishing weight called ballshot which is basically a lead ball with a hole in the middle. they are really cheap and will not spark at all.


now yt2095,

'and WHAT it has to do with E&W beats the hell outa me?'

it has FUCK ALL to do with E&W but my place here is as moderator. the forum must be presented to be intelligent. as anthony has said it gives the impression of retardation.

yes i agree with you the point in your post is valid. i didn't say it wasn't a valid point as you are aware.

'are there perhaps not more IMPORTANT things to complain about???'

i'll be the judge of that.

[yt2095]

OK,
perhaps i was a little deffensive yesterday as to my transgression.
your points are noted, and i shall TRY not to spell in that manor again (tho as mentioned it is a habit i`ve gotten into over 6 years now)
you have my word that any future posts will be edited asap IF i spot a slip up again.

i can`t say fairer than that :)

[blindreeper]

Though you should try and break that habbit, not just on the word fuck also others like the first one in this sentance.

Back on topic... I think it would be better to buy your own sinker mould and buy some scrap lead. I think it would be cheaper aswell. And sinkers with a hole in them are dangerous as if you were milling sulfur and then a couple months later chlorate there might be small amounts of sulfur left in there which is not good. Thus buying a mould allows the absence of holes. But if your lazy just get the crimp sinkers. They are kinda split in half and you crimp them with pliers on to the line. Although I have only seen these in smaller sizes. And using lead it makes you mill turn REALLY slow. Mine died cause I used lead sinkers :( Now I am just waiting for mums dryer to die so I get the motor plus all the bearings and belts. Maybe I should help it on it's way :D

[yt2095]

another alternative that i`ve used myself to great effect although not for a ball mill it was homemade lead shot for a catapult.

get some solder ingots or roofing lead, and melt them with a blowtorch over a large bucket of water, a bit like letting a candle drip.
then select the ones that you like the look and size of, these should be ideal for your use :)
and you can make kilos of them in an hour.
another idea occured to me also, bb`s the copper ones? now i have some here, but they seem to be copper plated steel (a magnet test) i`m wondering if solid copper ones are available anywhere? i suspect that they would probably be too small for a large operation, but maybe ok in a yogurt pot :)

[Total_CDRW]

I went to Wal*Mart yesterday, all they had were massive lead sinkers with holes in them so i found them too much trouble... i went searching through their BBs rack and all they had were Steel... they did have some lead pellets but they arent really round, almost as if they took BBs and mashed them... i dont think there are any gun shops around... otherwise couldnt i get some Lead Spheres from them? I decided since i cant find any marbles or lead spheres i'll just use the CIA method until i do... Tried to jam some CIA BP into a cardboard tube for a rocket and it flared about half way, then spurt 5 feet into the air... did i add too much weight?

[kingspaz]

Total_CDRW, can you give more detail of EXACTLY what you did? it may be that you pressed the BP. it should be loose for best results.

[Anthony]

You can get lead BBs, at 4.5mm they're a bit on the small side, but may be useful if you're working on a small scale.

[Total_CDRW]

i did press the BP... does that ruin it?

[kingspaz]

Total_CDRW, ok lets look at what BP actually is...

to make BP you basically mix sulphur, charcoal and potassium nitrate together. the more intimately it is mixed then the better the quality of the BP. this is because each grain of KNO3, charcoal and sulphur will be smaller and thus have a larger surface area exposed to the flame.

the KNO3 once given enough heat will decompose to release oxygen. this allows the charcoal and sulphur to burn in relatively low amounts of air, like inside a tube for instance.

now, when you light a match how does it burn? the outside burns first followed by the inside. if you split the match down the centre into 4 splinters and ignited them all at the same time then their duration of burning would be shorter than the whole match even though the amout of substance burning is the same. this is because the flame takes less time to reach the inside of the match splinter because it has a smaller diameter.

now, if you had very small sulphur, charcoal and KNO3 grains then they would react together faster as they had a larger surface exposed to each other. if however you pressed the black powder then you would remove the air spaces and gaps between the powder particles. what would this do? effectively you'd have turned it inot a big lump of BP instead of the fine powder full of air spaces that it should be. the air spaces allow the flame to accelerate around each grain of charcoal, sulphur and KNO3.

thus, low explosives (explosives which work by burning fast) such as flash and black powder work best loose.

does that help explain it?

[Total_CDRW]

so i should leave it grainy... or crush it before i place it into the rocket? and not tamp it down?

[kingspaz]

like i said, larger surface area gives a faster burn rate as there is a greater surface exposed to the reaction zone (flame). a powder has a much larger surface area than the same mass of material pressed into a solid.
so the finer you powder the BP the faster it will burn. so for best results you'll want to keep it as a loose powder inside the tube. then it will burn faster and therefore produce more gas in a shorter time. the gas is what causes the bursting of the tube. the gas can't escape so builds up and ruptures the tube.

[Total_CDRW]

Okay... I have no more questions...:D I completely empty... at least for now...