BP (meal) problem

[green beret]

Well I finally got some KN03, the same brand I had about four years ago. It used to work fine, but about two years ago I got some and used it with my BP and it wouldnt even burn. Its "incitec K-nitrate".

Now I have some (again) and it burns (in the BP) but there is a white residue that liquifies on burning and then hardens. It has to be the KN03 because it does the same with the sugar smoke mix. I'll tell you exactly what I did:

Weighed out chems in this amount:
750g KN03
100g S
100g C
Yes I know it should've been 150 of charcoal but I ran out, and planned on adding it later.

So I ground up the chems in that order, using a mortar and pestle, which about 2weeks ago I gave a coating of olive oil (its a stone one, all I have at the moment).

I then placed them in a seperate plastic container and then into a plastic bag to mix as the container was too full, I mixed for a while, and then poured it all back into the original container, the mix was fairly uniform, I was too concerned about the KN03 being crap, otherwise I would have done it longer, although I used to make shittier mixes than that and it was still OK for bursting pipes etc noisily.

Then I took a small test amount and put it on a brick, the BP (meal)layered about 8mm to 1cm. I put a lighter to it, it took a while to catch, (about 7 seconds) but it lit. It then burned slowly and left the afor mentioned residue. If there is a fire surpressant in the KN03 it most likely be too fine to sieve out, its all very fine powder.

So anyhow, I'm stumped as to what I should do. I really dont know, all help would be much appreciated, I love making good BP but without the right KN03 its impossible.

<small>[ February 06, 2003, 12:24 AM: Message edited by: green beret ]</small>

[a_bab]

Your problem is not KNO3, but the lack of comburants. The C lack, in this case. Those 5% really matters. Try to add some extra sulphur instead, although it's not a good method.
Meal powder is good for fuses and such; it never worked well for me. You can't use it for a rocket engine, at least not mine. I used KClO3/sugar mix instead.

You may consider other methods for making BP (CIA, ball mill).

[static_firefly]

To me it sounds like an excess of kno3 (not enough charcoal).

[Anthony]

In addition your charcoal might be of questionable quality. But the white pearls are definitely a sign of excess oxidiser.

Meal Powder, or Meal D is processed green meal. I.e. BP that's been milled but not yet processed into grains, I can assure you that it makes good rocket motors :)

[Kriegsminister]

I also noticed the same white residue in some of my mixtures containing potassium nitrate (I also use fertilizer grade).
In most cases this occured when I was in a hurry and just estimated the amounts needed without weighting. So I suppose it's because of the excess of potassium nitrate in the composition.
I didn't care much about the white residue since it worked fine anyway.

[NickSG]

The white residue might be impurities, or just the access KNO3 pearling, as said above. You should have made a smaller batch in the first place, so that your ratios would be perfect. If you havent used any of the BP yet, you could burn some weeping willow tree branches, crush up the ashes, and add 50 grams to you batch, so it would work better, but you would have to mill it or CIA it agian(i forgot which method ou used, but those seem to work the best).

[green beret]

OK Thanks for your help guys, I'm a bit relieved actually, I was setting up some stuff to purify my KN03. :o

So does my batch up the top look OK? Assuming that the C should be 50 grams more.
I used the ratio 15:2:3, but I always seem to do it the hard way when working this out, I think I did it right this time, what is the best method for calculating the weights of each chem? I just worked out how much I wanted ie; 1kg then I divided it into 20 parts (addition of above numbers) which gave me the weight of one part, then for 15 for example I multiplied the number by 15.

Im sorry but I have a habit of doing things the most complicated way, and overlooking the simple ways. All help would be GREATLY appreciated.

[Kriegsminister]

Well, you just figured out how to do it...
In most cases the ratios are given in percent (in this case 75/15/10), but the calculation is more or less the same.

Say you want 450 g of BP:

450 / 100 = 4,5 (One percent of 450 g)

4,5 * 75 = 337,5 (Amount of potassium nitrate needed)
4,5 * 15 = 67,5 (Amount of charcoal needed)
4,5 * 10 = 45 (Amount of sulfur needed)

As you can see the calculation is the one you already mentioned.

[Guerilla]

Or simply:

0.75 * 450g = 337.5g
0.15 * 450g = 67.5g
0.10 * 450g = 45.0g

There was somewhere a useful Excel table where you could easily calculate right ratios, can't find it anymore..

White residue that forms is a clear sign of over oxidized mixture, think it's K2CO3 or KNO2 but not sure..

[green beret]

OK thanks guys, I'll keep working at it, I wont use the charcoal that I've been using, I go back to the stuff I had years ago, I think I've got some unground, I'll grind some up and use it, unless I can find a willow tree, dosent seem to be many around here.

So I guess the excess nitrate was due to the fact that I had insufficient charcoal. Good. I'll let you all know how I go.

[KCLO4]

Your problem has to be too much oxidizer.The finer the chemicals the better they will work.I used fertilizer grade KNO3 and ran it through a blender. Very cheap garden sulphur and charcoal I just pulled out of campfires, washed, let dry, and again ran through a blender. You need extremely fine screen 40 mesh at least, but the finer the better --try a cement company. You can regrind seperately everything that won't go through the seive. Keep it away from the blender when mixed! If you can get your powder to feel "slimy" instead of gritty you're on your way to real powder. Too much water will make KNO3 cool into bigger crystals than you want. Once it is fine as you can get it mix it 15-3-2 K-C-S, dampen, rub through a screen onto papers to dry, and you'll be done.
About rockets: wetting is not necessary, just thorough mixing, adding extra charcoal, till they stop blowing up. It's useless for an N burning rocket but 90% of rockets sold have a hollow core made by a mandrill and you hammer each powder charge that way, no steel to steel. You'll have the best rockets and they cost next to nothing to make.Check pyrotechnics, esp. rec.pyro for what to put in the top.
Email me for for info. lysteria44@yahoo.com

[VX]

The most informative site I have ever found regarding the manufacture of BP is Dan William’s site: <a href="http://userpages.prexar.com/dwilliamsmaine/blackpowder/blackpowder.html" target="_blank">http://userpages.prexar.com/dwilliamsmaine/blackpowder/blackpowder.html</a>

The link has been posted around here many times, but I thought I'd bring it up again :)

[green beret]

OK Very good, I'll start over again and let you know what happens. Thanks. :)

[green beret]

Well, here's what I did:

Ground up some more charcoal, different type, dont know what but definately softer, added it (50g) to the mix, mixed well, and tested.
It ignites easier, burns faster, still has slight pearling. I think my scales might be a little dodgy, and I think the mix could use a little more charcoal and sulfer.

Some are probably wondering why I didnt just make some proper BP. Well, the powder I have know should be adequate for use in C02 bombs and pipe charges etc. and that is all I want it for. I am planning on making some proper BP at a later date using the CIA method but for now this powder should do, after a little tweaking.

So, thanks to everyones advice, I have learned that my KN03 is good :D and that mixing black powder is not as simple as I once thought. I have also learned that I will not be getting my charcoal from the nursery anymore.

I was under the illusion that black powder could be way out of the ratios and still work. This is because when I first made it, I was lucky, using measuring cups and just estimating, but I also realise that during that time my measurements were making me add more sulfur and charcoal. So thanks to everyone who has helped, I am more learned from the experience. :)

PS any oz people looking for KN03, get incitec K-nitrate, its good and pure.

[green beret]

I just tested some of this stuff, I got an empty roman candle tube, cut it in half, made a hole near the bottom for the fuse, (it fit too losely) and put confinement on the open end of the tube, made sure the powder was packed in tight, confinement was tissue paper.
Result:
The confinement on the end was too strong and the fuse hole too big, it ended up being a fountain out the fuse hole. I could tell the pressure was building but it wasnt enough. Dissapointed but determined, I tried again.
Attempt 2:
Same again but made the fuse a very tight fit and packed the powder more losely with about 1/3 of the original tissue confinement.
Result:
BOOM! It sounded like a cannon, I never realised meal was so potent! I love this stuff, Nice deep BOOOM.
I'm a happy little pyro now :D :D :p , especially since this is crap compared to what I could make.

<small>[ February 28, 2003, 04:59 AM: Message edited by: green beret ]</small>

[iron raven]

hello,
i have been trying to perfect black powder for ages. i mix my chemicals this way.

put kno3 into a conatiner add hot water( just a little bit) than add my charcoal and sulphur and need it together so it is like a cokkie dough. and then add metholated spirtis let it sit for a day in the container with the lid closed. Then spread it out and let it dry.

i have tryed making bp salutes. they just go bang and thats it. i can't get my bp polumna to work, they just shoot out the fuse so can anyone help me plz?

thanks to anyone who replys,
master of the atom
iron raven

[arm]

iron raven,

Making good BP is a lot of work.

Its probably your method of BP making thats to blame - it seems to be a poor derivative of the CIA method. The thing about BP is that it has to be very properly incorporated to work well. Another factor is the proportions, you have to be very precise when weighing out the components. Purity of the KNO3 can have an effect but normally, agricultural and better grades of KNO3 tend to work fine. A final factor is the charcoal. Sappy softwoods like willow and vines make the best charcoal. BBQ hardwood charcoal burns much more slowly.

To ensure a good incorporation of the increadients you MUST use either the (slightly inferior) CIA method or the ball mill method. Details can be found by patiently searching around this site. A ball mill is usually required for serious BP - its the best way to powder the ingeadients to the finest possible level. If you really want to go OTT with the whole thing Dan Williams' has a great page here :Black Powder (http://userpages.prexar.com/dwilliamsmaine/blackpowder/blackpowder.html)


Above all, patience, effort and great care are the best ingreadients in any pyro project

[Mr Cool]

Willow or grape are indeed the two most commonly called for charcoals for making BP, but barbeque charcoal will give a good product, as long as you buy lumpwood charcoal (£2.99/5kg from Wilkinson's, for example for fellow Brits) and not charcoal briquettes, which are made of charcoal and clay to hold it all together. They will give a VERY poor BP indeed.

[Argy]

Maybe these things are the solution for a nice BP : http://www.unitednuclear.com/mills.htm

And it's usefull for a lot of things, i think i'll buy one of them it's expensive but mixer isn't realy practical (i'm not sure of the world) for a lot of use, anyway it's attractive to make fine BP automatically, isn't it? :D

[Sparky]

Before you buy one from there, take a look at rec.pyrotechnics since there was a discussion about those mills a couple weeks ago. I would never buy one as one of my friends lives next to some company who installs water heaters and ducting. They often throw out ventilator fans which have 1/2 to 3/4 horspower motors in them, a belt, pullies, a drive rod and bearings - pretty much everything you need (the other stuff is everyday stuff that is easy to get) to make an ok ball mill for free and a good one for a few bucks. In fact he has given away two ball mill 'sets' already to friends. He uses marbles as milling media though I have heard that this is a bad idea, you could of course buy the lead media seperately or buy some brass rod at the scrap dealer and cut it up. Maybe if you phone around you can get a duct fan for free or cheap from one of these companies.

[blindreeper]

I have made extremly good CIA BP using frogforts method http://www.geocities.com/frogfot/pyro.html#gunp It burns damn fast even in powder form it burns like some of the lift powder I get out of roman candles. I think the trick is to have the acetone REALLY cold. My fidge (fridge and freezer) in my lab gets to -25 in the freezer compartment. I think it's way to powderful for rockets unless the nozzle was massive. But hey I'll try it. One last thing it works really good for Nap Charges.

[Dumbo]

A great source of lead media is .50 caliber soft lead ball bullets you can buy from a gunshop. Generally they are sold to muzzle-loading rifle enthusiasts but they serve the purpose of mill media perfectly.

[Sparky]

blindreeper: Cored black powder rockets do not generally use normal 75/15/10 unless it is really slow for some reason. They usually use more charcoal or just use the ingredients sieved together to make the mix much slower than normal processed BP. In SWIM's experience only very short rockets (about 2 cm long and 12mm thick ID of tube) will work with both normal (even slow) BP and a core all the way through. This is a ballpark figure since there are so many variables of course. SWIM has had success with using fast powder in an end burner rocket with a nozzle (like Estes engines) and nozzless rockets with a core the entire length. Nozzless rockets can use quite weak tubes because of the low pressure and are especially easy to make while still having a reasonable amount of thrust and burn time. Every time SWIM has tried to set off a reasonable length (about 4 cm length 12 cm diameter) black powder rocket with both a core and nozzle a loud CATO has occured. Besides using up a relatively large amount of black powder compared to other BP salutes, these 'rockets' would be good for black powder firecrackers. The rammed nozzle is quite strong (it shoul be at least ID of rocket tube, out of fine bentonite) so the container is strong and it is particularly loud.

[blindreeper]

Yes I learnt the hard way on a sunday afternoon about having full lenght cores on BP rockets with a nozzle. Especially when I was 5m with electrical fireing. Although it made a huge deep BOOM (I think it was around 50g of Mortar and pestle BP) the rocket went kinda upwards.

[iron raven]

hello,
on the subject of bp rockets, i have found instead of raming them, you can esaily mosten the bp with alchol and push it in. leave the rocket for about a day in warm sunny spot and it shouild be ready to fire the next day. they need no cores.
master of the atom
iron raven

[Mendeleev]

I am having problems very similar to green beret, my bp is very slow to light, it burns much slower than it should, and afterward it leaves a lot of that residue, a 40 gram batch glued about 15 gravel rocks on my driveway together with that white crap. My ingredients are slightly different, and most likely much less pure. I use green light co. stump remover for my kno3, my sulfur is alo green light co. but it is only 90%, and my charcoal is kingsford match light, the kind that doesn't need lighter fluid. Can anyone tell me how pure that brand of stump remover is, and how good the charcoal is? I know I shouldn't be using 90% sulfur, but I don't know the other ingredients so I can't purify it, furthermore in the whole mix its only about 1.5% difference. :eek:

[xyz]

The white stuff is just KNO3 that has beel melted and then cooled again, if it is left over it means there is not enough fuel in your BP.

[Bert]

Mendeleev:

Your nitrate is probably reasonably pure.

Your garden dusting Sulfur has about 10% diatomaceous earth added to prevent caking. This is silicates, it will melt to a glassy slag. Good if you're making a prime for stars, actually. I add diatomaceous earth to some star primes for this exact reason! But bad for BP for lift, rockets or crackers. That's some of the residue you're seeing.

Your charcoal is absolute shit. It is impregnated with hydrocarbons (oils, waxes) to make it "match light". In rocketry, if BP is too fast and blowing up the tubes such things are added to SLOW DOWN the BP. Also, commercial BP briquettes usually have a lot of other adulterants. Limestone to slow the burn, dextrin to glue them together, sometimes Sodium nitrate to speed them up/make them easier to light... Start over on the charcoal. Go find some willow sticks and a clean tin can and cook some of your own. Other things being equal, charcoal quality is the most important variable in the BP equation-

The old fashioned spot test for BP is to take a small pile and ignite it on a clean surface, such as a rock or tile. It should burn with a POOF! and leave no "pearls". Assuming the ingredients are reasonably pure and in the correct ratio, pearls indicate poor mixing or powder that has become damp...

As you all are discovering, making good BP is as much an art as a science. It is actually easier, and probably SAFER to make many single component HE's.

[Mendeleev]

Can anyone recomend a good brand of charcoal, I heard Wilkinson's metnioned, and I think they sell that stuff at my local food lion.

[Bert]

If you have commercial charcoal, a grill and can find a tin can- Make your own! Tkes an hour or two, and well worth it. First thing I did after I tried charcoal briquettes back when I was 12 or so.

[Mendeleev]

So I just put commercil charcoal into a tin can and grill it using more comercial charcoal?

[flash619d]

Originally posted by Mendeleev
So I just put commercil charcoal into a tin can and grill it using more comercial charcoal?

No, you put twigs of the appropriate wood in the can and grill it using whatever heat source is available. I have heard willow and pine reccomended, with willow being far preferred.

[Bert]

The process is called "destructive distillation of wood". It was one of the first labs I ever did in 8th grade chemistry, as I recall. Take your wood to be made into charcoal- I recommend any species of willow, European buckthorn (black alder) or cottonwood, grape vine also works well- and fill a container with it, one that can be closed TIGHTLY. A clean metal paint can was my preferred vessel for small batches. It will go more quickly if your wood is in pieces less than 1" or so thick, split any bigger branches. Some people also de-bark the wood, with willow this never seemed to be necessary to me. Put a SMALL vent hole in the BOTTOM of the container, close the container tight and place it above your fire in the grill. After a short time, smoke will come out of the hole in the bottom. The smoke is flammable gases released by the process, it will hopefully catch fire and burn, the additional heat from this burning gas under the container will help the process along. After a while, gas will stop coming out the hole. Wait a few minutes after the gas stops, then pick the can up (using tongs or similar) and set it down on some sand or loose dirt. This will stop air from going in the vent hole on the bottom of the can and burning up your charcoal. Wait until the can is COMPLETELY cool before opening it, this will be at least a couple of hours with a 1 gal. can. If you don't, it will catch fire as soon as you open it. The wood should be completely black and snap easily. Grinding it with a coffee grinder or ball mill will be easy if it's completely carbonized. Wear your dust mask and don't borrow your mom's kitchen tools... She will NOT be happy if the next time she uses the blender there's black specks in everything she makes.

[Mendeleev]

I don't think I have willow here, but I have tons of pine, literally, so how effective would pine charcoal be in my black powder?

[tiac03]

i'm new so i haven't gotten around to reading all the threads so hopefully no one has posted this black powder recipe before.

i always used the 75,15,10 mix before now i use a mix i found in a book about medieval warfare in the school library.

by mass, not volume

KNO3=74.64%
charcoal=13.51%
sulphur=11.45%


"the ideal mixture was (look above) but since accuracy was difficult in the battlefield (where they mixed the KNO3 to the sulphur/charcoal mix (to prevent accidental explosions)) they approximated it." (i assume with 75,15,10) i'm just quoting from memory, not exact quote.

and that is it from me. the mix workes well for me, hope it does the same for all of you.

[Bert]

Pine will work, bu it would be better for making charcoal stars than powder for lift or reports.
Willow grows EVERYWHERE. Go to a city park that has water, or look by a stream or lake. They're the trees that hang down over the water... Black alder is a common weed tree, and also used for hedges.

[apathyboy]

Wouter visser's site says to ball mill the KNO3 separately from the charcoal/sulfur mix for the ball mill method. Is this necessary, or can you simply put all the weighed materials into the ball mill together, wet them, and let it go?

Here's the site, in case you can't find it. http://huizen.dds.nl/~wfvisser/EN/bp_making_EN.html

[tiac03]

they say that for black powder only, you can put the 3 ingredients in the mill. (making sure that there is no possibility of sparking. (use lead balls or any non-sparking material.) but they also warn you to keep it in a place that if it ever did "go off" it won't cause too much damage to surroundings.

link where they say that. (great link for firework making tips and techniques)
http://www.unitednuclear.com/bp.htm

[Bert]

All the ingredients can be placed in the ball mill together- IF and ONLY IF you have a place to put the mill where it will not be dangerous if it blows up, and a means of stating & stopping the mill remotely. And don't wet the mix before ball milling. In fact, dry the nitrate at low temps in an oven if it's humid. The idea that wet milling was good comes from the days of using edge runner mills. It was needed then, for a number of reasons. Ball mills like a completely dry charge. Lead balls will wear rapidly. Brass will last longer, non sparking ceramic is what I currently use.

[Mendeleev]

Why is a ball mill necessary, couldn't you just use a blender? I put my ingredients in there, one by one and even on low power, after I open the blender, the whole thing is a very fine powder, and a lot of it comes of as a vapor, because its so fine.

[arm]

Firstly, I wouldnt like to be anywhere near the blender when its going.

'Steel blades at high rpm' + BP = likely disaster.

Secondly, a ball mill is better at physically grinding the ingreadients into one another, especially grinding the KNO3 and sulfur into the charcoal pores.

[Mendeleev]

Great, thanks for the advice. Also, Bert, what kind of metal is your paint can made of, carbon steel? Normally cans are make of aluminum or tin: melting point ~900 and 600 respectively. They would most likely melt in the fire. I thought about using a glass jar, but the thin metal top would surely melt and the non-pyrex glass would crack.

Edit: I also remember reading somewhere (and I will try to find the source) that oak charcoal was good because it is porous?

[Bert]

The paint cans are made out of steel. You don't want a fire any hotter than necessary- A fairly low temperature will do, too high a temp first drives off the volatiles which are needed for fast powder and then starts to convert the structure to graphitic. Don't continue to heat much past the point where flammable gases are coming from the vent.

Oak charcoal is good for grilling and adding to rockets to increase the tail, but doesn't have a reputation for fast powder. If you have to find a different wood than the recommended ones, start with woods that grow FAST and are relatively LIGHT. Cottonwood, soft maple, box elder...

[Mendeleev]

I have decided to start producing my own charcoal and I will buy a paint can tomorrow, today being thanksgiving and all the stores being closed. However I came across an idea while thinking about buying a gas mask. Gas masks use activated charcoal in the filter, but then I remembered having taken it in the past, while I had a bad case of stomach flu/food poisoning. Activated charcoal is also sold at pharmacies for upset stomachs and food poisoning OTC. I was curious if this "activated" charcoal would work.

[arm]

There was a discussion somewhere else on the site about activated charcoal a while ago. Too cut a long story short, activated charcoal usually sucks for BP making for various reasons (wood type/volatiles etc).

[tiac03]

i stick to the mortar and pestle, works for me. oh and if you actually go out and buy charcoal you should have your head examined.

quick guide to making charcoal (and warming up house)

materials required

-wood burning stove
-paper (any kind but glossy) newspaper and looseleaf work great.
-small pieces of wood (branches, large splinters of wood)
-logs (must fit in fire place)
-ignition device. (matches, lighter, bow and drill)

optional materials
- gasoline,BBQ fuel, or lighter fluid


step 1: start fire in stove.
A)crumple up paper in to loose wads and line bottom of wood burning stove with it.
B) now add a layer of little pieces of wood "kindling"(sp.?) on top of newspaper
C) take ignition device and proceed to light paper on fire.
D) once kindling catches on fire nicely feed more of it to the fire. (increase the size of the pieces of wood you feed to the flame)

step2:

A) once fire is burning nicely begin to add dry logs. (bonus to doing this: house warms up)
B) when stove is hot enough toss in logs let them burn abit. then close off the air vents to the stove. (causes a slow burn) and go to bed. in the morning you should have charcoal and a nice warm house.



alternate method:

put logs in right away, soak with accelerant, step atleast 5 feet back, light a match, and toss in fireplace.



from what i've seen any charcoal works well (from fireplace) as long as it looks like charcoal (black chunks of what appears to be burnt wood) then it burns like charcoal.



(i also heard pouring water on red hot charcoal (taken out of fireplace) will leave you with good charcoal (just so that the charcoal doesn't burn to ash)



And that brings an end to my modest tutorial for people who have been dropped on their heads as children.


"if you can easily make your own stuff, why spend money on buying someone elses"

isn't what this forum is for, teaching people how to make things so that they don't have to buy from others?

[Marvin]

Fireplace charcol is... fairly poor. Typically high ash content, unreliable as a a method and a product and not well performing. Charcol intended for fuel is usually worse performing, but more reliable. Retort charcol does well and at home you can control the degree to which volatiles are left in, as well as the source of the wood/plant matter. Having used a pestle and mortar for many years Ive conluded that its a waste of time. Grinding mixtures takes forever and the quality of the gunpowder produced is usually dissapointing. I can easily understand why someone would want to just buy charcol and concentrate on the more enjoyable parts of pyrotechnics. Reliable batches are frequently more important than ease of manual grinding you need for pestle and mortar work, being the major advantage of fireplace charcol over bought, and unsurprisingly using manual grinding and fireplace charcol tends to go hand in hand. For what its worth I consider the fact you are not using a rock tumbler half full of marbles, or similar ball milling device with suitable safety precautions - that you were probably not dropped on your head enough as a child.

[tiac03]

(i used sandpaper for grinding charcoal) and anyways using a tumbler takes away from the experience i find. mightest well just stop making black powder. (since making it is half of the experience)

as for the charcoal... i once used charcoal parents had bought for a charcoal BBQ. personally i saw no difference in that one and the stuff i cook up in a fireplace. both work the same. and there is no way i am going to spend money on a product because it is "perfect" charcoal if there is barely any change in the performance of my powder.

btw it was a trade off, i was either going to be dropped on my head as a child or electrocuted.... so i stuck the house keys in the wall socket.


shit i just lost the strands of copper wire i was going to use for rocket igniters/electric blasting caps. knocked em off my desk and can't seem to find the lil' bastards.


like the sig, good ol' marvin.

[Mendeleev]

Thank you all for insulting me, it was exactly what I asked for... In the meantime let me explain to tiac that I am making by own charcoal using Bert's method, I was just theoretically curious about the pharmacy charcoal. Let me explain to Marvin that I don't grind the finished product in a blender, only the charcoal-sulfur mix, after which I use the precipitation method.

[tiac03]

i wasn't directing that comment to you specifically. i was trying to point out that in life we need to do as much as we can ourselves. for example charcoal anyone can make, and it is rather easy to get decent charcoal just by leaving a fire to its own device. true it may not be as high quality as the charcoal from the 2x45 gallon drum method i saw on a website, but it works well too.

its bad enough that they charge us an arm and a leg for chemicals we can't easily make ourselves (then the taxes), we don't need to go out and spend good money on something like charcoal. spend it on citric acid or acetone, something that you can't make cheaply and effortlessly. (to my knowledge)


this will be the last time i reply to this (without offering real advice) because i bet there is somethig in the rules that says what we are doing here isn't allowed.

[apathyboy]

Bert: I was under the impression that damp milling was a way of combining the grinding and corning process into one step. Maybe my info is a little old (~1600 :p ) but I thought that corning produced higher quality BP as the nitrate dissolved and soaked into the charcoal, carrying the insoluble sulfur particles into the pores with it.

Or do you just corn the powder after you mill it?

[Bert]

Damping the mix and running it in a ball mill usually results in the powder getting stuck to the walls. As the milling happens when the mix is struck between and rolled on by the media inside the mill, once this happens nothing much useful is being done to the powder.

In the 1600's, the powder would have been made in a stamp mill or an edge runner mill. With either of these, the water would have helped the incorporating process and reduced losses as dust. It also would have helped dissipate heat build up from the milling process. In all cases, the powder would be corned after pressing the mixed product from the milling process to as high a density as possible. Ball milled powder may be slightly damped after milling and before pressing. Adding water to powder can be either beneficial in helping nitrate to penetrate the charcoal, or detrimental if it dries in such a way as to re-crystallize in crystals larger than those left by the mechanical milling process... Degree of damping and drying regimen are important factors.

The procedure on Dan Willam's pyro page (http://www.wecreate4u.net/dwilliams/blackpowder/blackpowder.html) is effective. You will note that he uses a mix of alcohol and water to damp the ball milled powder before pressing into cakes. Alcohol added to a saturated nitrate solution in water causes the nitrate to precipitate- The alcohol mix both dries faster than pure water would and helps prevent the formation of large nitrate crystals as the powder dries.

[syndicate7]

wet BP will stick to the sides but i don't think it would matter if you didn't want very fine powder as the leads ball will roll around and pound the BP anyway and as apathyboy said it will dissolve the KNO3 and carry the S into the pores on the charcoal.

[arm]

I have tried damp milling and every time save once, the BP stuck to the outside of of the mill and failed to mill well. Also you have to take care because (according to Dr Shimizu) BP's sensitivity actually increases until you pass 3% moisture content.

Would it be possible to create a cement-mixer style mill for those without the space for a closed mill. This would be a mill that works at an angle (~45 degrees), which is partially or completely open at one end. To stop material falling out the front you could use vanes (like a cement mixer again) near the top to deflect the powder/media back into the mill.

[Bert]

The losses from an open mill with dry ingredients would be large. The flammable dust cloud would be dangerous, unless you had a totally sealed motor you would likely have an ignition.

I do know folks who use a MODIFIED cement mixer with bocce balls to mill star compositions. But they secure a plate over the open end of the mixer and replace the factory motor with a sealed unit. Also they remove the vanes and weld over the holes.

[arm]

Good point(s). How about a thin seal over the top like, clingfilm? Just enough to seal against the escape of dust but thin enough to prevent explosion by burning away or perforating??

The worst you could then do is turn your ball mill into a cannon/flamethrower and blow a hole through the roof! Mindyou, if the missus/mother finds out you'd probably wish the mill had exploded in your face. :D

I'm trying to think of safe, workable alternatives for those without space.:confused:

[Bert]

These guys use a piece of plywood held on with bungee cords.

arm-
What makes you think that an open mill needs any less space than a closed one? No matter what, it MUST NOT be in your house or garage, and MUST be far enough away from anything or anyone that might be damaged by fire or explosion. The question isn't IF your mill will explode, it's WHEN, and WHAT will be damaged. If you can't maintain safety distance, don't mill just now. You can always try it later when you've got the correct location- if you're alive and aren't in jail.

BTW, I know one unlicensed individual who ran a ball mill in his garage in his suburban neighborhood. His neighbors and his insurance agent turned him in to ATFE after he blew up his garage, and I don't blame them. Idiot.

One more time:
"It is essential that persons having explosive substances under their
charge should never lose sight of the conviction that, from the facts and
general truths which have just been stated, preventive measures should
always be prescribed on the hypothesis of an explosion."

Is that too long to use for my sig???

[arm]

Well speaking for myself here, I dont run my ball mill in my garage or house and you wouldnt catch me doing it in a million years. It is located some 150/160ft down the garden in a sand bag covered pit which is in turn in an old shed. But judging from the posts here, there people who do not (and will not) have this kind of room, but will still pursue their hobby in a practical way and neither you or I can stop them.

What makes you think that an open mill needs any less space than a closed one?

The fact that a tightly closed mill has no quick release of pressure and will likely explode in a most devastating fashion. Whereas a film-sealed mill would blow its top in a way similar to the blow out panels on a modern battle tank or just result in a fireball, which, although not particularly nice is better than the former scenario.

A film sealed mill is a preventive measure prescribed on the hypothesis of an explosion.

Please dont go all rec.pyrotechnics on me here bert (i.e. end up flaming each other after two posts). I like to think of this site as a place for friendly information exchange & debate.:)

[Bert]

The worst you could then do is turn your ball mill into a cannon/flamethrower and blow a hole through the roof!

Forgive me if I took that to mean you intended to run your ball mill indoors-

[PanMaster]

my ball mill is made of rubber and i run it in the garage with a max of 200 grams of blackpowder, in the unlikely event of explosion it will have several advantages over keeping it outside:
1-The walls of the garage prevent shrapnel/minimise damage/sound
2-Neighbours cannot see the source of the explosive BANG
Since the barrel is rubber it will not creat any real shrapnel and its lid is lossely attached by a rubber seal that simply pushes in, thus at worst my ball mill would gain a black mark and the barrel might get a bit burnt. There is an alcove inside the garage that used to be a toilet where there are two thicknesses of walls in every direction, I couldn't think of a safer place to put it.

[arm]

What about the media panMaster?

[Bert]

You might get a surprise from the overpressure of 200 g. of BP fired in a closed space- Like the garage door blowing out and/or inside wall towards your house moving a few inches. That's what happened to the guy I knew who did this. The dummy CALLED HIS INSURANCE COMPANY instead of paying to fix it himself, and told them and his neighbors the truth, that he was making rocket fuel in his garage. Both called the cops. BTW, 200 g. of BP will make enough smoke so anyone looking that way will likely notice something odd.

Hope you don't keep any flammable liquids or fueled vehicles in your garage.

[arm]

Just a little side question here.

Has anyone tryed balsa wood charcoal? From what I've read, its supposed to be better than willow (but expensive).

[tomu]

Hi there,

I haven't tried balsa wood but I made my charcoal of straw. Straw is plenty where I live. Just packed an old cooking pot full of straw, screwed the lid tight with some C-clamps and put it on a slow charcoal fire in the BBQ. The BP made with this straw charcoal worked nicely.

Arm: I made a cement-mixer style ball mill. It was made of an cooking pot fastened to the axel of an slow turning (90 rpm) e-motor and the whole thing tilted at an angle. It didn't work very well, the milling area is to small. A horizontal milling jar (tube) works much better, the milling area is much larger with more media actively grinding and it gets much more tossed around inside.

Have fun
tomu

[pornopete]

I havent tried balsa but I think it would work quite well as its soft, but willow to me is the ultimate.
I think i mite start a thread of different ball mill designs if anyone thinks this is a good idea.ive got a mill made out of an old wind screenwiper motor it works really good.

[Bert]

I haven't tried balsa wood but I made my charcoal of straw. Straw is plenty where I live. Just packed an old cooking pot full of straw, screwed the lid tight with some C-clamps and put it on a slow charcoal fire in the BBQ.

In the black powder era, a particular type of powder was made with charcoal from rye straw less than completely carbonized, with no or little Sulfur. It was known as "cocoa powder" from the lighter brown color and had a use where a slower, longer burning powder was desired, as in long range artillery and long barreled rifles for distance shooting. See Tenney Davis, CPOE pp. 41 - 42.

[tomu]

Well Bert I couldn't say that I got slow burning powder with this straw charcoal, but I completly charred it. I've got no means for testing the speed of my powder. But it made fine salutes and I also do some muzzelloader shooting with my powder and it worked quiete well.

By the way the french were using the rye straw charcoal.

[Mendeleev]

I have been making charcoal, but just to make sure my powder is good, I have undertaken to purify the 90% Greenlight sulfur. I dissolved it in HCl, even though it didn't dissolve, and let it sit for an hour at which point it accumulated on the bottom. I then poured out the majority of the HCl and dumped the sulfur onto a piece of paper and let it dry under a light bulb for a day. Now the sulfur tends to clump a lot more, which I have heard it should. Does anybody know how pure this refined product might be?

[Bert]

If you didn't rinse it with a good deal of water, probably not completely pure. And I have no idea how soluble diatomaceous earth even is in whatever concentration of HCl you used.

Suggestion- Melt a sample of the Sulfur. Hold it molten for a while, then let it cool undisturbed in a tall narrow vessel, perhaps made from aluminum foil so you can just peel it off the hardened slug of Sulfur. The diatomaceous earth will likely have fallen to the bottom or floated to the top, I don't know what it's density is relative to Sulfur. Break off whichever end has the contaminants and re-mill the now purified Sulfur. BTW, Sulfur has the interesting property of not shrinking measurably between the temp. it solidifies in a mold at and room temp. That's why I don't suggest you do this operation in a vessel you want to keep in one piece- We used to cast a Sulfur slug in rifle chambers and extract it to measure chamber and throat dimensions due to this dimensional stability.

[Mendeleev]

Just to be sure the diatomaceous earth is on top, I'll probably keep the temp between 160 and 195 Celsius, at which temperature sulfur becomes about 100,000 more viscous than a little over its melting point which is 113, because the S8 molecules break and it just forms huge chains up to 300,000 atoms long, which get tangled. Also, I have stopped making my own charcoal, because for those of you in the U.S., there is a pure non-briquette kind, its called "Western" and is labeled as "100% natural, burn hotter than briquettes" I felt it and it is a bit more flaky. I didn't find it before because I was looking in Food Lion, which is a relatively small store, whereas Publix is a huge grocery store, and they have it.

[apathyboy]

Wierd, I just had a conversation with my Dad in which he suggested using the real non-pressed charcoal that some BBQ purists use. What has been your experience with this type of charcoal Mendeleev? IIRC most of it is mesquite charcoal because it supposedly gives more flavour to the meat. Will this make good BP?

[flashpoint]

Maybe these things are the solution for a nice BP : http://www.unitednuclear.com/mills.htm^--- 3 pound capacity Ball Mill -- 69.00

Same one, click here, its 24.99! (http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=46376)

[Bert]

The 12 lb. model shown is my current small mill. However, you can buy it for a good bit less from Eloxite, Inc. (search...)

United Nuclear is one of the most expensive pyro suppliers in the US. If they have it, someone else will ALLWAYS have it too, and for less.

(edit-)
Just looked at their site again, it's even worse than I remember. $10.50 (+ $7.50 shipping) for a single 3" gun? These cost me less than $2.00 to make. KNO3 for $8.00/lb.- It costs me about .50/lb. (+ .25/lb for shipping in less than truckload quantities).

[flashpoint]

Bert,

How much would you say your media weighed in your 12lb mill?

[Bert]

I don't go by weight. I use ceramic media, and fill the mill to an apparent volume of 1/2. The fill of the substance to be ground should then just fill all the spaces between the media and slightly cover it. I could check the weight next time I mill and get back to you-

[flashpoint]

Not a big deal...I'm just pondering how much media to buy :) I'm trying to figure out if I want to use Lead Antimony....or ceramic...what's your opinion?

[Bert]

Ceramic or stainless steel would be my choices. Lead, even hardened lead, will wear very fast and contaminate your chemicals. It's also heavier than necessary, making your mill work harder than it has to. I mill BP type mixes with Coors ceramic media and have had no problems, regardless of various speculations circulating on the internet that it could spark. I mill remotely anyway though, it's allways best to assume you WILL have a problem eventualy...

[flashpoint]

So ceramic, does, or does not spark? I imagine anything, could spark, given the right conditions. I'm just confused about this....I have an area outside in my backyard, where I have concrete bricks that make up a little "hut" type deal, I made it for my goat I had hah...mom sure loved that one...anyway...its under my old treehouse..I guess I could run the mill there, and just watch out for flying concrete :)


EDIT: By the way, Bert, do you cook your own charcoal? Just curious...I'm using Silver Maple to cook mine, today being my first go at cooking it...I had a maple in my backyard the whole time, didn't even know it....I used to have a willow tree, wish I still had it :) Anyhow...I put my shaved twigs I guess you could say, in an old cookie tin I got from in the kitchen....I poked a few holes in the top, placed it on the grill, and as of now, its smoking...how do I know when its done? I hear if you check it, take it off the flame, as the gases are flammable or something...anyhow I'm waiting to see the results...I guess I'll cook it, until it doesn't smoke anymore. If you have any suggestions....let me know...thanks.

[pornopete]

when smoke stops coming out of the holes its ready, take it off the heat cover the holes and leave to cool..

[SpiffyVision]

Originally posted by arm
Secondly, a ball mill is better at physically grinding the ingreadients into one another, especially grinding the KNO3 and sulfur into the charcoal pores.

I've been thinking about it, and I'm wondering weather this really even happens. According to my book "Black Powder Manufacturing, Testing and Optimizing", the author states that this is a common misconception. If you think about it, he could be right. I can get my charcoal to be quite a bit finer then my KNO3 (dont know about the sulfur). To think that KNO3 could go in a PORE of one tiny little grain of airfloat charcoal just doesnt work. Anyone wish to clear this up?

[Sparky]

Pete, if you leave the charcoal to cook long enough that there is no smoke coming out, that is too long. That's not to say it won't work at all just that generally it's considered best to take the charcoal off the fire when the smoke is dying down but not gone completely.

Flashpoint, you seem confused (I guess I don't understand what you are talking about very well but since I am posting...). The smoke coming out of your cookie tin is quite flammable, if you have the whole on the bottom of the container the flame can help to cook your charcoal. As for when to stop cooking, lighting the smoke and watching the height of the flame is probably easier than trying to judge how much smoke is coming out. Obviously if you start with green wood you will drive off steam first, which will look quite similar to the smoke and not burn.

The problem with opening up the container to check and see if the wood is black through is that when you open the container if the wood/charcoal is still hot from the fire then it will start to burn as soon as it gets oxygen from the air. You don't want it to burn as this will leave you with ashes. Leaving it to cool takes a long time. So in other words don't open it up to check it, use the height of the flame as an indicator instead.

[blindreeper]

To check charcoal, I usually open it up and take it off the fire, take out a stick of the charcoal and break it in half to see if it's cooked fully. To cool the charcoal I dump all the contents of the cooker into a large cooking pot and put the lid on. It is a sealed one so it keeps the O2 out thus having the least ammount of ash possible.

[flashpoint]

I basically, took it off the flame, and checked it, after about 10 minutes of cooling. It was fully cooked, I actually forgot about the charcoal, and was posting on here hah...then I sent back out and opened the grill lid, and saw the labels, on the tin were burning, it was weird too, I took all the paper ones off, but I suppose the ones painted on there have a burning point as well...so they were burning, I thought it was the gases, it wasn't though, it scared me heh. So I let it cool in the grill, while having the grill turned off...after about 10 minutes, like I said, I removed it from the warm grill, and checked the contents. Nice black, somewhat sparkly sticks, that look thourghly cooked. Although I didn't snap them, I'll check them again tomorrow, considering I smell like a redneck, trailertrash idiot that's just roasted a pig head in the ground :)

[Crazy Swede]

SpiffyVision, the grinding and compacting in bp manufacturing is all about increasing the intimacy between the particles.

There will always be some pores left in the charcoal particles, no matter how fine they are. A wet process helps the potassium nitrate to soak into the charcoal and heavy pressure from milling actually makes the sulphur somewhat plastic which also enables greater contact with the other ingredients.

[Bert]

I've made my own charcoal for BP. We currently buy GOEX from Western Powder by the case as we need the consistency and don't have time to manufacture that much BP. We still make rough powder (polverone) by the wet process for shell filler and use the fines for star prime. BP type star compositions are milled (without metal!) where faster burns are needed, as in spiderweb stars.

If you're cooking charcoal in a can, put the holes in the BOTTOM of the can. This allows the gases to burn under the can and add heat. Also, all you need to do to shut off air to the contents after removing from the fire is set the can down on some sand or dirt, covering the holes. Stop when the smoke becomes thin and no longer easily supports combustion but is still noticable would be my advice if you're trying to make fast BP. For tailed stars, you might want to cook longer.

[flashpoint]

Bert, I put holes in the top of the tin and the bottom of the tin...I'm guessing that could have been a mistake, although I do have some nice looking charcoal...now I'm just waiting on the sulfur to come in. I just paid today for it...so it should be a few days.