Newbie: A Few Basic BP Questions

[AntarcticFX]

Howdy, my fellow pyro's here at the APC Forum. It's a pleasure to make your acquaintance.

 

I'm fairly new in the art of manufacturing pyrotechnic compounds. I spent months researching safety procedures, the best wood types to use for charcoal, how to make charcoal, and reading tons of pyrotechnic / firework books and research papers before actually deciding to make any compounds myself. An from reading so much I know that many self-respecting pyro's will strive to master the art of producing quality BP before trying to move on to anything else. That's what my goal is at least.

 

A little bit about my current setup for producing BP; I don't use a ball mill, I don't use a mortar & pestle, nor a blender / coffee grinder. I separately grind the ingredients (mainly just C, my KNO3 / S is already super super fine) into a very fine floating dust by hand prior to beginning the integration process of the three components. I do not use any type of binders either when granulating.

 

I follow a guide written by a gentleman who frequents these forums that was designed for creating non-milled BP, and you'll have to excuse me but I've forgotten his name as I downloaded the guide months ago from a thread I stumbled across.

 

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Upon completion of getting my components to the fineness that I desire, I then place them in an anti-static mixing container and hand mix all three of them with a paint stirrer for about 120 revolutions.

 

I then place the mixture into a sieve and sieve it through into another anti-static container, before proceeding to repeat the step listed above. I repeat both steps 1 and 2, alternating from one container to the other until I have a very homogeneous mixture (To the naked eye it's homogeneous; I perform this initial mixing process for an hour or more)

 

At this point I take a 70/30 mix of alcohol and water and begin to stir it into my compound until forming an almost play-doe like consistency before pressing through a screen and granulating it, at which point I will let this sit out in the sun to dry until it's ready to perform.

 

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Now believe it or not, I actually can produce a finished BP using this method that is capable of being used for lift purposes, it's not anywhere near blazing fast during an open burn and is lots and lots of work to make, but confined it does the trick which is good enough for me.

 

My question is, when doing an "open burn" test, it will burn but there always seems to be these extremely small molten hot white balls, almost like miniature BB's that show up when it's burned through and they stay hot for a little bit of time after the initial powder has burned (Like 1 second). Maybe 5 - 7 of these BB like objects will show up from open burn testing a 0.5g pile of BP, you see them roll around very briefly while they're still red hot (blink of an eye) and then that's it.

 

Does anyone have any clue what this is? Is it KNO3? I only ask because all of the burn tests I've seen people do, they did not have this phenomena occur. Even watching people burn powder as slow or slower than mine did not have this occur.

 

Edit: If I see white specks in my mixture still after it starts to dry does that mean I need to re-mix it and add more water to help integrate the KNO3 more?

Edited March 17, 2019 by AntarcticFX

[Carbon796]

The method your talking about is one that was refinded by Dave F, though im not quite sure what handel he goes by on here.

 

Yes, its unreacted kno3. Your charcoal probably isn't fine enough, it really needs to be ball milled extremely fine, for this method,iirc. Also stirring isn't really going to integrate the comp properly. Pretty much all comps benefit from being properly screen mixed.

Edited March 17, 2019 by Carbon796

[AntarcticFX]

The method your talking about is one that was refinded by Dave F, though im not quite sure what handel he goes by on here.

 

Yes, its unreacted kno3. Your charcoal probably isn't fine enough, it really needs to be ball milled extremely fine, for this method,iirc. Also stirring isn't really going to integrate the comp properly. Pretty much all comps benefit from being properly screen mixed.

 

I don't own a ball mill as of yet, and refuse to use the CIA method to make BP. I am using untreated Balsa to make my charcoal however, so turning the charcoal into a dust or "air float" is as easy as rubbing it between my fingers briefly, so taking a rolling pin to it in increments in a double sealed bag works very well. The amount of volume to weight for charcoal you get using Balsa as opposed to what I was using before which I believe was Pinus radiata is absolutely insane.

 

I'm still very very new to the actual hands on process of making BP, so any input is greatly appreciated and I thank you for helping me answer my question about the KNO3.

 

So basically if I used a little bit more water I should theoretically not see white specks in my drying mixture anymore?

 

Also, I do have plans of purchasing a ball mill in the future I'm just currently limited on funds as I'm looking to invest in something that will last in the long term, seeing as I've taken such a liking to the hobby / profession of pyrotechnics I'd rather invest in quality items that will last a long time and will produce quality products with consistency.

 

I do still have plenty of Balsa that's good to go for charcoal though that I think I will save a large majority of for after I purchase a ball mill.

 

I understand the importance of the ball mill (or any mill) in the production of many different pyrotechnic compounds. I was just like one of the I'm sure many others who was holding onto a glimmer of hope that they could produce high quality BP by methods considered either simple / crude / or ancient.

 

Thank you again for your help, Carbon796!

[Carbon796]

If your kno3 was purchaced pre-milled. It's most likely your sulfur. Because the comp was not screened.

 

Kno3 can leach to the outside of a comp if over wet with water, and re-crystallize. But its not likely given the 70/30 mix and the limited amount your wetting it.

 

Regardless of weather you have a ball mill or not you still need a proper mixing screen ( 20 to 30 mesh , my preference is the 30, but plenty of people use a 20 ) you can do alot without a ball mill, but you'll still need to be able to screen your comps correctly. Not using or having a proper mixing screen is probably one of the most over looked, useful tools by "newbies"

 

http://bucketscreen.com

 

Balsa is VERY lite and fluffy, and breaks up easily. But by hand, you'll never come close to what a ball mill can produce. Get or make a good screen before you get a ball mill. It will most likely make an improvement, while your waiting on a ball mill.

Edited March 17, 2019 by Carbon796

[AntarcticFX]

Understood. I currently only use a kitchen grade sieve to put the compounds through, so I can see how that can pose a problem. I am unfortunately not using pre-milled KNO3 either, my sulfur is much finer just by visual standards than the KNO3 is. My KNO3 still clumps itself together though before it's mixed with anything else. They're pretty small granules, probably a little smaller than table salt.

 

Now with a 30 mesh screen, is it possible to push the compounds through if they don't quite go through it? Is that a no-no? I'd imagine it would severely wear the screen since it's a dry mixture you're trying to push through it.

 

So even with amazing charcoal the importance of a completely homogenous mixture, pretty much a triangle of KNO3/C/S granules all around is still very high? An I'm not achieving that properly due to my horrible screen? That makes sense.

 

Thank you once more, Carbon796 for the tips and the weblink.

 

Is it possible to get 20-30 size mesh screen at any major retailers in the states, or would I have to order them online like the bucket screens?

[pyrokid]

With all the effort you are dedicating to making black powder, you should stop and order a mill right now. You should devote your energy to crafting novel and intricate effects and not grinding powders. Life is short! With my mill, I throw all the coarse ingredients in and turn it on. Four hours later, I open it and I have fast black powder.

 

If you're willing to scrounge components, a proper mill can be built for relatively few dollars.

[Carbon796]

Ok, your kno3 is way to coarse also. You can blade mill it with a coffee grinder. DO NOT blade mill charcoal. A good mixing screen will be stainless steel. It won't really wear. Ive put hundreds of pounds of comp through mine, probably more . . . You can push soft clumped ingredients through, but still granular items will be a difficult waste of time. The kitchen screen is better than stirring, but not ideal.

 

Mcmaster carr carries screen.

[AntarcticFX]

Thank you both, Carbon796 and pyrokid for the advice.

 

The method I am using is indeed extremely labor intensive, and the end product is certainly something that leaves you wishing for more with all the effort put into making it. It seems like the most logical solution is indeed to just outright purchase a ball mill and proper screens, unfortunately something I won't be able to do for at least another month due to monetized priorities.

 

I have attempted to scrounge up the necessary materials to make a make shift ball mill to no avail. I was unable to come across a suitable motor for the job, and probably would need to invest in media as I don't really have anything suitable laying around besides lead fishing weights. I am pretty handy, and am the type to make something if I can do so before I go and buy the same item for 5x more, but it seems I don't really have a choice in the matter when it comes to a ball mill.

 

As far as ball mill media goes, what would be the best choice economically speaking for media? Non-sparking, even though I won't be 3 component milling, the notion of ball-milling all 3 components together makes me queezy. I would still prefer it to be media that doesn't produce sparks though. I don't like to cut corners when it comes to safety, especially when dealing with pyrotechnics.

 

Edit: P.S. Many many months ago when I was still trolling through the forums as a Guest account, one of the very first posts I came across happened to be "The aftermath of a ball mill turned IED" due to 3 component milling with, I believe it was glass marbles, maybe? Either way, a swift but firm thud was given to the side of the milling jar to empty both the media and meal powder out into the screen, the marbles clashed together creating a rogue spark inside the jar, thus turning said milling jar into a giant grenade with shrapnel in it. That post, the pictures, the dangers, and the story of it all will forever be seared into my memory and I am upset that an event like that befell that individual in the first place, but in sharing that experience it allowed me (and hopefully many others) to solidify in my mind that my number one rule when dealing with any pyrotechnics is "You can never be too safe." If there is something I can do to minimize or completely remove potential dangers / hazards of working with the things that we work with, you had best believe that I'm implementing it.

Edited March 18, 2019 by AntarcticFX

[AntarcticFX]

This is how 12.5g of that crude powder I made looks.

 

https://ibb.co/4PqN6d5

Edited March 18, 2019 by AntarcticFX

[ollie366]

A next logical, low cost step would be to use a dedicated coffee grinder for your KN as another poster mentioned. They're around $15 and are great for small batches. The ground KN drifts into the air when you open the cover it's so fine and what's left in the grinder doesn't feel at all gritty with the "between the fingers" test. Then try your play dough technique- I think the BP will be a lot better than what you're making. Don't grind anything but the KN in the grinder.

[AntarcticFX]

Thank you, ollie366 for the insight on the coffee grinder.

 

I do not own a coffee grinder, as I buy my coffee pre-ground so it never occurred to me to purchase one. I do however own a household blender and a "Magic Bullet" blender which I believe is like the Samurai / Ninja of blenders. Do you think that either one of those would work? I have taken my KNO3 through my household blender one time, it was before I stored it back into the container and not all of the KNO3 was a fine dust after blending, but there was tons of floating particles when I initially took off the lid, even after waiting a few minutes for it to settle.

 

I suppose that didn't prove to be fine enough though, I thought the KNO3 wasn't that much of a priority when it came to particle size due to the fact that it gets integrated into the charcoal when you introduce the 70/30 alcohol/water mixture to it all.

 

This is why I registered here though, the more you know the better. There are plenty of helpful people here, it's really a great community and I'm excited to dip my feet into the profession of pyrotechnics with the help of everyone here. An I would rather get advice from people that have much more experience than me, as it will help take out a lot of the guess work in my own ventures and allow me to expand my knowledge on designing pyrotechnic formulas and devices for myself and to share with others to come after me.

[Carbon796]

The ball mill incident you are referring to. Was NOT due to 3 component milling. It was due to improper milling media and handling.

 

Blenders have to much open space/volume to be effective.

 

Theres not really going to be much integration/dissolving of the kno3 when using alcohol or even cold water. Thats why the cia method is heat based.

Edited March 18, 2019 by Carbon796

[AntarcticFX]

Carbon796, what if I could essentially reduce the total volume of the blender to about an inch or less clearance above the blades?

 

An you are definitely correct about the KNO3 integration when it comes to water temperature. I'd completely forgot to factor that in.

 

What about using near boiling water to mix before using alcohol, would that make any significant difference or would it only integrate properly into the mixture using the actual CIA method? I was really trying to stray away from using the CIA method.

[justvisiting]

AntarcticFX, I've written a few articles about pyro, including making BP with single-component milling. The fineness of the charcoal is very important. If you don't have a mill, shaking the charcoal in a plastic jar with lead shot after you powder it coarsely might be helpful. Recently, a challenge to make lift powder using commercial airfloat charcoal was issued. I was able to achieve this, and asked to write up the procedure. This method might help give you a powder that is closer to what you want, even though it is NOT presented as the best way to make lift.

http://pyrobin.com/files/How%20To%20Make%20Lift%20For%20Shells%20Using.pdf

[AntarcticFX]

AntarcticFX, I've written a few articles about pyro, including making BP with single-component milling. The fineness of the charcoal is very important. If you don't have a mill, shaking the charcoal in a plastic jar with lead shot after you powder it coarsely might be helpful. Recently, a challenge to make lift powder using commercial airfloat charcoal was issued. I was able to achieve this, and asked to write up the procedure. This method might help give you a powder that is closer to what you want, even though it is NOT presented as the best way to make lift.

http://pyrobin.com/files/How%20To%20Make%20Lift%20For%20Shells%20Using.pdf

 

justvisiting, thank you very much for the link to your article. I will also take into consideration the idea of adding some sort of media to a handheld sized plastic jar and shaking to produce finer particle sizes until I can get a ball mill. That manual approach theoretically should work, if you shake it at the right speed to induce maximum impact between the media and the component in the jar I don't see why it won't work, it will just be labor intensive. I'm already devoting a lot of energy to making my powder though, might as well devote a little more if it means that it will be that much better from having finer sized particles.

[Arthur]

Everyone I've ever heard of including the CIA has started trying to make BP the simple/easy/cheap way and ALL of them have found their powder to be useless or little better.

 

Spend the money, get a cheap harbor freight rock tumbler and half fill the drum with ceramic media from inoxia.co.uk. Yes they sell and dispatch world wide.

[AntarcticFX]

Everyone I've ever heard of including the CIA has started trying to make BP the simple/easy/cheap way and ALL of them have found their powder to be useless or little better.

 

Spend the money, get a cheap harbor freight rock tumbler and half fill the drum with ceramic media from inoxia.co.uk. Yes they sell and dispatch world wide.

 

Arthur, I'm dedicated to getting a mill of some sorts working and decent media, I've just got to save up the extra money to drop on them as of right now. I'm not necessarily in a hurry, but do plan on acquiring all I need to make some decent lift powder within the month at least. I do appreciate the link to the website for purchasing milling media, and I see they have other goodies on there as well, so I will definitely be bookmarking them.

 

Now with a rock tumbler the milling times will be a couple hours longer than a properly optimized ball mill, correct?

[Arthur]

IME a simple rock tumbler will NOT turn a half load of lead balls but will turn a half load of ceramic balls hence the supplier link. Yes a fully optimised ball mill will work and work faster but it will cost more money unless you already have a good pile of old bits to scavenge for motor, shafts belts and pulleys etc.

 

I have milled for 12 hours, (whether I needed or not!) simply by turning the mill on before going to work and turning it off when home from work. If the mill is quiet enough and remote enough I could run two loads per day.

 

A rubber drum and ceramic media usually make the quietest mill. Which helps if you have neighbours!

[AntarcticFX]

Fortunately, I work from home so being able to tell if the mill is too loud won't be an issue as I'm pretty much here most of the time and would most definitely notice with the quiet environment I'm in.

 

Thank you for pointing out that a rock tumbler will properly turn ceramic media, but won't turn lead media right, or I may have went off and bought the wrong media and ended up with a set back. Doesn't ceramic media spark though? That's what I thought at least, correct me if I'm wrong though.

[spectra1]

A cheap Harbor Freight double drum rock tumbler WILL easily turn a single drum filled half full with lead media. I use mine all the time and make great fast BP. Mill for three hour and granulated with dextran and water. It's simple it's cheap and it works.

[spectra1]

It also lasts just fine in terms of durability. Mind you I'm not making hundreds of lbs of BP. I have probably made over 50 lbs of BP with my little tumbler.

[Mumbles]

Both the single and double drum rock tumbler have the same motor. I found giving the jar a hand start or starting the rollers and stopping the jar on worked fine for me, but it would struggle to start from a stop in its own full of lead. The biggest downside to the single jar mill is that the jar is rubber and tends to run more and might stick a bit without a spacer. Furniture sliding pads work great.

 

Your mill time will vary. For some 3hr might work, for some 12. I found 8 was optimal for me. I think it depends a lot on the particle size of material you're starting with, and how soft or hard your charcoal is. Media diamter, media material, any caking, and a whole host of other things will also affect milling time. Just find what works for you.

 

Harbor freight mills turn about half of the optimum rpm. The 8he I mentioned above is on a stick setup. Speeding it up or building a better base down the road can cut down on the time required.

[AntarcticFX]

It also lasts just fine in terms of durability. Mind you I'm not making hundreds of lbs of BP. I have probably made over 50 lbs of BP with my little tumbler.

 

 

Both the single and double drum rock tumbler have the same motor. I found giving the jar a hand start or starting the rollers and stopping the jar on worked fine for me, but it would struggle to start from a stop in its own full of lead. The biggest downside to the single jar mill is that the jar is rubber and tends to run more and might stick a bit without a spacer. Furniture sliding pads work great.

 

Your mill time will vary. For some 3hr might work, for some 12. I found 8 was optimal for me. I think it depends a lot on the particle size of material you're starting with, and how soft or hard your charcoal is. Media diamter, media material, any caking, and a whole host of other things will also affect milling time. Just find what works for you.

 

Harbor freight mills turn about half of the optimum rpm. The 8he I mentioned above is on a stick setup. Speeding it up or building a better base down the road can cut down on the time required.

 

@spectra1 I'm not going to be making large scale batches of BP at one time either, so that may just be the perfect option for me, and it's fairly cheap.

 

@Mumbles Thanks for the helpful tidbits on the Harbor Freight mills. Also, I'm not pressed for time. Even when I do get a mill, 12 hours of milling time won't bother me any if that is the case to produce decent powder, at least for now. If things work out as planned I could see myself investing much more money into the hobby and then at that point, I would want to be able to turn out a batch of BP in about 3 hours if I'd be using a lot of it very quickly.

 

Just getting my bearings on making good BP allows me the luxury of benefiting greatly from even a basic Harbor Freight mill, so I think I will stick with purchasing that and some decent non-sparking media in the near future.

 

Out of curiosity, with the standard jar that comes with a Harbor Freight mill, what is the largest batch of BP you could make at one time if half of the jar is to be filled with media?

Edited March 20, 2019 by AntarcticFX

[Arthur]

People have used pestle and mortar powder, BUT in real life the absence of good powder in an assortment of size grades will impact negatively on everything that you want to do.

 

Get a starter mill and make (and store safely) three different size cuts of powder. Then to make an item you can simply weigh out what your design says that you need. Even having powder that is properly dry helps making reliable and repeatable products.

[BetICouldMake1]

The optimum load for a single jar is about 4oz.

 

This is where many have started for their first mill https://www.skylighter.com/blogs/how-to-make-fireworks/quick-easy-black-powder-ball-mill

 

These mods are cheap and easy and will make a big difference in the necessary mill time.

 

 

Also, casting your own lead media is not difficult, though it is time consuming. Even if you factor in the cost of buying a mold and the lead ingots, it will be a fraction of the cost of buying media. A casting pot is nice, but you can get buy using a sturdy pan on camp stove and a ladle if you're trying to minimize cost. The other nice thing is once you're set up to cast media if you decide to upgrade your mill you are set up to cast more media. I recently upgraded from the harbor freight mill and cast 35lbs of media for under $50 rather than buying it for about $200.