Black Powder

[A_W]

This might be a stupid question, but here goes:
The formula for blackpowder is by weight 75 % potassiumnitrate, 10% sulfur and 15% charcoal right? Supposed I don`t have a scale and I wish to make it by volume (for instance teaspoons). What are the ratios by volume?

[xoo1246]

If you knew the density of the chemicals, you could calculate it, now go search before the forum monsters eat you alive. <img border="0" title="" alt="[Eek!]" src="eek.gif" />
And you will probaly be dissapointed if this is the first time you make bp. Mixing the stuff together isn't good enough if you have the intention to make make good pb.

[RTC]

Well you should be able to work it out from your own post, for example you said:

"75 % potassiumnitrate, 10% sulfur and 15% charcoal"

If you were measuring it out with tablespoons, you could do say, 7 and a half for 75%, then 1 table spoon of sulfur, and one and a half of charcoal.

Not exactly the best way to measure something, but in a crisis it will work.

[Anthony]

BBQ charcoal briquettes are useless because they use a slow burning charcoal but also because they are full of clay.

A stright swap of weight units for volume units is useless as good charcoal is many, many times less dense than KNO3 or S.

If you really have to do this rather than spend £/$10-£/$15 on some digital kitchen scales then I'd do the KNO3 and S as 75:10 by volume and then use trial and error to get the charcoal quantity right. But as was said, if you're simply mixing the components with little or no grinding the result will be shite even if you have the perfect ratios.

[kingspaz]

the chemicals you will be mixing are powders. if you squash the powder its density will increase. if you shake a powder around in a container its density will decrease as more air mixes with it. what i'm getting at is that powders do not have a consistent density.

its woth investing in cheap diet scales. the measure in 5g intervals so they are accurate enough for BP. if your going to do it do it properly.

[xoo1246]

True, but he asked for a method not using a scale. Best I could come up with, although I agree with you.

[ALENGOSVIG1]

Well, ive made bp lots of times and i usually dont even weigh the chemicals anymore. I just adjust the chemicals until it burns the way i wannt it. and the volume of charcoal is usually more than the volume of the potassium nitrate. This all depends on the density of your charcoal ofcourse.

[xoo1246]

I felt like telling it, charcoal has an approximately density(g/cm3) of: oak 0.57 and pine 0.28-0.44 .

<small>[ March 11, 2002, 07:56 PM: Message edited by: xoo1246 ]</small>

[NoltaiR]

Ahhh... the one thing that I probably have more experience with than anyone else here, improvised BP.

As you stated, the 75:15:10 ratio is for weight only; if you try to do this by volume then you will be WAY out of proportion and your final product will have extremely poor performance (assuming that it ignites at all). Coincidently, although I make BP just about everyday, only a few times have I ever used a scale to measure it. (After a while you can just poor your charcoal, sulfur, and potassium nitrate into a coffee grinder and estimate pretty close)

Anyways according to the IM handbook, use a 3:2:½ ratio by volume of GRANULATED KNO3:PULVERIZED CHARCOAL:POWDERED SULFUR
This procedure is pretty much exactly what the book says, but everything in parenthesis are my comments.

This mix is put in 2 parts water and heated until it is 'bubbling' (not boiling or else you will evaporate much of your KNO3). Once heated it is removed from the heat source and put in 10 parts alcohol (I use 91% isopryl) and allowed to stand for 5 minutes. (During this time the KNO3 will crystallize around the grains of charcoal and sulfur and settle at the bottom.. so sometimes I let it go a few minutes longer than 5). This mix is then poured through a cloth (preferably something with VERY small pores or else you will lose a lot of your mix that hasn't been able to crystallize large enough to be filtered out) and then rubbed through screen wire (which can take a lot of work, so plan on finding a rock or something with a hard, smooth surface because your hands will tire out far to easily to do it without something to hold). Let the wet granules sit in the direct sun until dry or under the radiator of a vehicle (I have also found that if you are making at night and sunlight is not available, setting it on a paper towel ON TOP of a refrigerator--assuming that my refrigerator isn't the only on that is warm on top--will also be acceptable). The granules need to be completely dried within an hour, any longer and the performance will suffer. (This is actually not easy to accomplish.. I don't think I have ever had mine completely dry in an hour since I have been making it, but the closer you get, the better the product... and although it may feel dry to the touch doesn't necessarily mean the grains are completely dried all the way through.. the best way to tell is when the smell of the alcohol is pretty much gone).

--What I have discovered from my work on improvised BP....

For one, use soft wood (willow tends to work best), this is what this procedure is for and using hardwood will make it burn very noticeable slower and sometimes cannot even be ignited with a naked flame because hardwood is much more dense, and more KNO3 will be required. The only time you use hardwood is in pyrotechnical displays when you use GRANULES of charcoal to produce orange sparks or when using to heat an object very rapidly (I have found this useful when sticking a capped-up pipe filled with softwood BP or flash in a small pile of the hardwood BP.. the pipe will heat up very hot and the composition inside will ignite) or when using with a bit of Al to ignite compositions such as thermite because the hardwood produces a much greater amount of heat.

Anyways, from then on its trial and error. Ignite a small amount of your mix and if it burns just right then great (because you have managed something that I have only managed to do a very few times).

But...
------------
* if it burns too slow but does not produce a noticeable (by smell) amount of SO2, then stick all the granules in a coffee grinder and add some KNO3 and blend it in.

*if it burns fast but leaves too much WHITE residue, then you have too much KNO3. Make a small mix of 7:1 charcoal:sulfur and grind it with your granules.

*if it burns fast but leaves a yellowish residue, then you have too much KNO3 and sulfur. Add some charcoal to the granules and pulverize.

*if it burns slow and SO2 is evident, make a mix of 7:1 KNO3:charcoal and grind with the granules.

(Note: these are approximate editions.. I usually can tell what needs to be added and therefore I don't measure anything out--also due to the fact that I have very little patience--)
------------
Then ignite a bit of this (although it will be all pulverized) and if it burns well then stick the mix in a bowl and add enough alcohol to make it into a thick paste and pour out thinly over a sheet of newspaper then let it dry in the sun until it hardens. Then stick chunks of it on the screen wire and start rubbing it through as before with a rock until all of it is in granules. (Sometimes I don't do this last step and use the pulverized form of the BP although there will be much less surface area to burn and it will require much more confinement to have equal results).

---------------And if you are very impatient like myself and just want to make a batch of BP just whenever...
I pour in some pulverized charcoal in the coffee grinder until it is about ¼ full. Then add a few tablespoons of sulfur. To this add KNO3 until it is almost full (slightly below the top). Then grind away occasionally shaking the entire mixer to make sure that it is all mixed. When the mix is completely one color, pour out and test. If not as good as possible, then use the methods that I described earlier for mixing it, but just leave out the last part of adding alcohol and making it into granules. What you will have is a powdered form of BP which only took a couple minutes to make and is still quite effective although as stated earlier, it will require a much stronger container for confinement to have equal results to that of granulated BP.

Also if you used the IM handbook method, then your final BP will be relatively waterproof, unlike if you made it without alcolhol in which it would be quite hygroscopic and it would clump together easily, requireing that you repulverize it before use.

Personally I use my homemade BP to make 'metal crackers' as I call them which the procedure I described earlier about filling a pipe with the BP and sticking it in a pile of hardwood BP; also I use it very extensively in mortar shots and my pyrotechnical uses (although the commercial grade BP is far better). I have also used my improvised BP as solid grain rocket fuel by dampening it slightly with alcohol and then putting it in the casing. When dry a hole is drilled and primed with either a sugar/KNO3 mix or commercial BP or pyrodex.

[A_W]

Thank you for some very good instructions!

<small>[ August 30, 2002, 01:31 PM: Message edited by: A_W ]</small>

[CyclonitePyro]

Not to bust on your methods but from what I heard the ball milling method produces black powder of a higher quality.
I'm interested in this method since I hae a ball mill. But it seems like the CIA method would be better if the KNO3 coated the charcoal and sulfer. Anyone make ball milled black powder?

<a href="http://huizen.dds.nl/~wfvisser/EN/bp_making_EN.html" target="_blank">http://huizen.dds.nl/~wfvisser/EN/bp_making_EN.html</a> I read his page on making it, anyone have any comments to improve his methods when ball milling?

[Anthony]

There's not a lot to ball-milling. You just weigh out the component chemicals, throw them in the jar along with the media, set the mill running and go find something else to do for the rest of the day (depending on the efficiency of your mill and load).

One thing I would suggest when first using a mill is to stop it periodically and test the burn rate of a sample of the contents. After a certain time you start getting diminishing returns and it becomes more worthwhile to stick another match in the mill rather than try and squeeze the last few drops of performance out of an existing batch. I used to let my small mill run for 7-8hrs when doing BP.

The great thing about ball mills is the minimal effort and cost compared to other methods such as the CIA method.

[NoltaiR]

Although ball milling tends to be the traditional method to the long-lived pyros of our time, I have never taken the time to make one simply because although it requires no physical effort, it is not made for someone like me who expects to have made it and have used it all within a couple hours.

Also, as stated before, the CIA method (for those of you who may not know, this is another name for the method of taking advantage of KNO3's ability to dissolve in water and then recrystallize around the other nonsoluble materials) provides for a much quicker way--takes work though--and when using alcohol, the BP tends to lose its hygroscopic properties which is VERY useful in the event that I have to do something else and cannot use the BP right away.

<small>[ March 12, 2002, 11:34 PM: Message edited by: NoltaiR ]</small>

[NoltaiR]

And one more thing about the not using charcoal briquettes: this is very true, however I did not always know that it was (although I should have taken a clue from the first time that it wouldn't ignite) and after having dissappointing results with it, I made a 'BP substitute' (as I called it) made of pulverized chlorine granules, pulverized briquets, and sulfur using the ratio of 75:15:10 by volume (back before I knew better).

Even this would not ignite, but when I put a small charge of pyrodex on it and ignited it, the mix burned very energetically although only a small amount is needed due to the fact that the amount of fuel in general burns quite slow. I even put it to use in shooting off a few mortar shots :D

The only problem I ever had with this stuff happened last july (the last time I made this mix) when I discovered that if you attempt to store this mix it will spontaneously ignite and if I had not had it locked up in a stainless steel tool box I would have burnt down my garage.

I also found that adding a small amount of gasoline (just enough to dampen it) could sufficiently replace using sulfur, however it was a bitch to ignite because the gas fumes tended to burn above the actual mix, making it hard to ignite at all. Also I found that this mix as well self-ignites after about 20 minutes or so.. however I had this mix in a metal bowl about a meter from my dad's van and I melted the bumper (thankfully that is all).

The reaction was quite impressive, first I noticed that a thick smoke was pouring out of it (well actually it was most likely chlorine gas) for about 3 minutes which I waited out expecting that it was simply going to stop. Well instead the gas hung low over the ground and once the mix had self-ignited, everywhere the gas had gone, it ignited as well in a huge flash of light.

Once the flash was over and it was just the bowl that was burning like rocket fuel, I managed to throw a rock at it and knock it off the garage cement, although this resulted in the mix pouring out onto the yard. After all was done I had a scorched driveway and about 2 hours of cleanup time...

Anyways just a little story I thought I would share..

<small>[ March 12, 2002, 11:52 PM: Message edited by: NoltaiR ]</small>

[vonK]

I make my black powder using a ball mill.
I decided on this method because when I started I could only get NaNO3 which is incredibly hygroscopic and I don't the CIA method would work ( I could be wrong).
I built my mill from an old sowing machine. I switched the originally motor with one from an Expel-air unit and epoxied the lid of an old drano container (my milling jar) on to the wheel that lets you turn the machine manually.
This worked like a dream for many, many hours but the motor burnt out recently.
I just chuck the right amount of chems in and let it run untill the powder burns fast enough for me.
It takes around 10 hours to get nice burst qualitly powder.

[NoltaiR]

Well actually I believe I may have just learned something new.. according to the webpage, the isopryl needs to be ice cold before using.. I may have to try this, the strange thing is that this step seems so obvious to get better precipitation although I have found no other information source that stated to do so.

This would also probably help save as much precipitate (another disadvantage of the CIA method is that at least 25% of the original chemicals are discarded at the end because they did not recrystallize well enough).

[kingspaz]

the longer it takes for the temperature to drop the bigger the crystals which form will be. therefore if the BP and water is added to very cold alcohol the crystals which form will be minute.
i believe ballmilling is the way to the finest powder. or maybe the CIA method followed by ballmilling would acheive the best results....

[HOOPS123]

Noltair, is putting all of the chemicals into the coffee grinder at one time really safe? I have heard that it isn't. Have you had any bad expieriences?

[NoltaiR]

I have also heard that mixing Al and KNO3 in a coffee grinder can be dangerous.. but I have never had any problem with it and I have been making all sorts of Al flash compositions and BP at least once a week for the past year or so and I have always used a coffee grinder.. and I have only had to replace the grinder once because I was grinding up chunks of charcoal for some hardwood BP to be used to heat up and bend some steel conduit and one of the chunks that I picked up happened to be a rock! Thank God that didn't make a spark... but it chipped my blade up bad so I couldn't grind near as well.

And no, I have never had it spontaneously ignite in my grinder.

[vulture]

I was freakin' crazy one day and i put 50g (yes fifty) of H3 into the coffeegrinder. Ran it for 2 minutes and had airfloat H3 :D
I must have been very lucky because i repeated this 2 times.... :cool: :p

BP in a coffeegrinder is no problem, but don't do it with flash.

I get good quality BP by the following steps:
1. Add the KNO3 and the charcoal together and mix thoroughly
2. then add the sulfur
3.put the stuff in the coffeegrinder
4. Wet with aceton. isopropyl or water until you got a high viscosity paste
5. Let dry (you'll notice there are alot of tiny reflective spots in it because of the recrystallized KNO3)
6. crush the chunks and put the stuff back into the coffeegrinder
7. Wait 5 min before opening the grinder, otherwise you risk a powerful FAE!

For some strange reason my BP is of worse quality if I first mix the S with the KNO3 and then add the charcoal... :confused:

[Anthony]

Possibly because the S binds with the KNO3 crystals, making them less likely to enter the pores of the C. Ideally, the KNO3 enters or recyrstalises in the pores of the C and is bound in place by a small amount of S. That's the theory anyway.

[A_W]

I did a quick scearch, and did not find anything matching this. I also did not want to start a new topic for this, so I posted it here.
Has anyone heard of those charcoal-sticks used to draw pictures with? I recently "borrowed" some from school, and I`m wondering if they can be used for blackpowder-manufacture. (are they made of soft, or hard wood?)

<small>[ March 22, 2002, 03:42 PM: Message edited by: A_W ]</small>

[kingspaz]

charcoal sticks? they are not worth stealing! grpahite sticks however are, they make great electrodes since they are nice and fat compared to pencil graphite.
to make charcoal, chop up some softwood into pieces about 1-2cm long and about 0.5cm wide (small pieces basically!).
pack this into a tin so there is as little air space inside as possible. put the lid on. and put a hole in the lid no more than 0.5cm in diameter. next put the tin on a fire with the hole facing upwards. the tin will smoke for a while. when it stops or it thins considerably, take it off the fire and leave to cool. when you open you will have charcoal left. if the smoke that comes out the tin catches fire it doens;t matter, just leave it. the smoke is carbon monoxide so don;t breath it!

[Anthony]

I'm guessing that artistic charcoal sticks are going to be way too dense (probably pressed during manufacture), homemade charcoal sticks (out of the can, off of the fire as Kingspaz describes) are very low density and break very easily.

[YTS]

Artistic willow charcoal doesnt work its crap it is to dense & is hard to grind ive tried it afew times . Also costs a fortune for a few sticks

[Pu239 Stuchtiger]

I hope noone interprets this as being "arrogant", I am just trying to help. :)

Grinding all of the ingredients of black powder in a coffee grinder is a death wish. Of course the only opinion here from people who do that is going to be "it's safe, I've never had an accident" because those who have had an accident aren't going to be around anymore. All it takes is *one* spark, and *BOOM!!!*... dismemberment. Grind the ingredients seperately, and spend twenty minutes mixing them by hand in a glass bowl with a spoon (do not use a metal bowl AND spoon, can cause sparks). Clean out the coffee grinder after you grind an ingredient in it. If you want to be more precautious (recommended), then buy a seperate coffee grinder for reducers / oxidizers (as in, grind only KNO3 in one coffee grinder, grind only sulfur and carbon in another coffee grinder). Powders slowly accumulate inside of coffee grinders; if it is a mix of a fuel and an oxidizer, it could cause an explosion (the interior of the coffee grinder can get very hot).

[vulture]

First of all, blackpowder isn't going to ignite, let alone explode from a simple friction spark. Keep in mind that a friction spark is not hot burning material like a spark from a burning composition is.

Second, for an explosion to occur in the coffeegrinder, there must be pressure build up which is impossible im my case because there are venting holes in it and it has a plastic lid which would immediatly melt in case of ignition.
Besides, 40g of BP aren't gonna make an impressive boom and if it explodes it's with a very low velocity.

It also depends on the blade of the coffeegrinder, if it has sharp pointy blades it will cause more friction than just a simple metal rod like mine has. Also, if you're grinding compositions, let it run for max. 1min, shake it, grind again and check temperature.

[Anthony]

The sparks you get from grinding or striking metals together are burning particles of the metal.

[Pu239 Stuchtiger]

I do not know what kind of coffee grinder you are using, but the ones around here require you to have your hand ontop of the coffee grinder when it is running. With mine, ignition of the black powder would result in third degree burns on my hand and arm, if an explosion did not occur (warm / hot black powder in *my* coffee grinder would explode if ignited). The thing that matters the most is power of the explosion, not detonation velocity. For example, ethyl nitrate is very brissant, but it is not powerful. 40g of exploding black powder would have no trouble taking my hand off. Especially when there are bits of plastic shrapnel present to assist... (I have a light plastic cover for my coffee grinder also, but it isn't going to be vaporized in an explosion).

Pretend the chance of your black powder igniting when you're grinding it in the coffee grinder is 0.5% (I think it is higher than that, but I'll shoot low so that noone can complain that I exaggerated the risk). What would be the chances that you will have had an accident after grinding black powder in a blender 1000 times? According to my calculations, ~99.335%. 100 times? ~39.423%. 200 times? ~63.304%. 300 times? ~77.771%. 400 times? ~86.534%. And so on... it isn't the single act that is so dangerous, it is the habit.

[kingspaz]

well the way i see it is, if people want to risk being maimed or whatever then thats their choice. but please people, who have not had accidents grinding oxidisers and reducers together, don;t say its safe. it isn't. it increases the risks substantially. newbies who don't know any better could be maimed by this.
vulture i have proven to myslef that BP will ignite from a friction spark. i have sparked a run out lighter over pea sized amount of BP before. it lit first time - energy is energy.

[YTS]

I personally wouldnt grind all the ingredients in a coffee grinder. The coffee grinder ive used actaully grinds between wheels rather than use blade as some do but each to his own

[00Buckshot]

I use the coffee grinder method to make my BP. I just wanted to add that I make my BP by first grinding to chems seperate. Then you could mix them by hand and get pretty fast powder. Or you could take a (slight) risk mixing them together in the grinder to get a faster powder.

Remember the post that said BP burns better if the sulfur is added after the KNO3 and C have been mixed.
Well after the chems are ground seperate, why not then grind the KNO3 and the C together and then mix in the S by hand.
Thats what I do, because I figure that a KNO3/C mix would be MUCH less explosive compared to BP with the S. Is that right?

Also I open up my grinder and clean out the powders on the motor and stuff before each use.

[HOOPS123]

Coffee grinders can be a pain to clean out. Even after you clean it out water always seems to be stuck way down in the cracks. Generally, do you people think its safer to grind you chemicals together in a coffee grinder or ball mill?

[RTC]

Staying with the coffee grinder's, is it just mine or is there always a bit of wetness in the grinder after you've dryed it? :mad:

[HOOPS123]

yeah, it happens to mine to. What I do is open the top and get a pen to press the button down. It spins all the water out.

[NoltaiR]

Just depends how you do it.. I suppose you guys like to wetten your mix first and then let the clump dry and then grind it. What I do is grind it then take the powder and mix it with 91% isopryl and then rub it through a wire screen.. therefore there is never any wetness actually in the blender.

[00Buckshot]

I don't wet my grinder ever. I don't wash it with water.

But the thing about adding the alcohol after and pushing it through a screen, I found that to slow my powder. I just grind the stuff and thats it. It burns great.

[NoltaiR]

I have never known rubbing it through a screen ('corning it') to have a negative affect on it (I have always known it to add to the burn rate quite effectively due to the added surface area), but I guess to each his own...

[BoB-]

Dude, you dont have to make a ballmill, just pick up a rocktumbler, then swing by a gunstore and pick up some muzzle-loader ammo to use as media. The thin plastic on the tumbler is actually really strong, I've used mine for about 3 years now and there are only a few sctratches here and there.

Damn guys, dont use the button on the coffee grinders!! Get out the extension cord, and take the plug with you, then duct tape the button down on the lid, then plug the coffee grinder into the extension cord then plug the extension cord into the wall for the grinding cycle while you are far away and behind something big.

Safety first!

[Pyroboy]

Bob do you know of anywhere on the net that sells rocktumblers?
This wouldn't be what I'm looking for would it? lol

<a href="http://www.totallyfuntoys.com/cgi-bin/toys/602NS?JisTLCjR;;19" target="_blank">http://www.totallyfuntoys.com/cgi-bin/toys/602NS?JisTLCjR;;19</a>

<small>[ April 10, 2002, 08:29 AM: Message edited by: Pyroboy ]</small>

[HOOPS123]

Yeah, thats it. Kinda small though... may want to try to find a bigger one.

[nbk2000]

You ALWAYS grind your ingredients seperately.

Then, once the components are finely powdered, you mix them together by tumbling or seiving. NO friction or tumbling media! Just simple mixing.

Once it's wetted down, then you can use grinding media, but don't let it dry out or else BOOM! As often happens at professional BP plants.

[Pyroboy]

But what I don't understand about that NBK2000, is if the mixture is dry, and your media doesn't create sparks how do you get an explosion? Just from heat build up from the friction?

[Anthony]

Static might be the culprit, especially if your mill is driven by a belt.

I must admit that I've always milled BP dry. I didn't grind and sieve the chemicals together before hand either, although thinking about it, it would probably significantly reduce the milling time required to get a fast powder.

[nbk2000]

Sulfur can become highly charged with static electricity. You may notice this sometimes with sulfur powder flying around in a jar by itself.