Greetings Rogue Scientists,

The fourth of July is approaching, that wonderful holiday that is enjoyed by people of all ages, always entertained by the never ending fun of fireworks. As I'm sure you assumed, I, like so many of you, have a passion for pyrotechnics and always enjoy setting them off this time of year, in a controlled, supervised, safe enviorment.

I manufacture my own black powder, and thanks to some help from members of this forum, I have successfully gone from troubleshooting my first, faulty batch of black powder to manufacturing an excellent product on a regular basis.

Now, I typically deploy black powder for use in model rockets. However, with the upcoming holiday, I thought I would attempt to make some black powder salutes, hoping for a satisfying boom of sorts. So, recently, I purchased some small pyrotechnic tubes and caps, filled one with fine homemade black powder, capped both ends, made a small hole on one end, inserted a fuse, and lit it at a length that would allow me to reach a safe distance.

It did not do what I expected/wanted. Instead of exploding(I know that BP deflagrates, I couldn't think of a better word though), it simply made a pop. It didn't do anything at all, except burn the top cap out and char in the inside of the tube a small amount. I performed a couple other similar tests, using duct tape to attempt to stop any escaping gases and achieve a "boom", but to no avail. In my tests, the Black Powder simply burned.

So, I decided to present this problem to the good members of this forum. I assume I assembled my BP tube in a manner that was incorrect, and I'm sure someone will point out my problem right away. However, I was simply unable to troubleshoot the problem on my own. So please folks, let me know what you think may have gone wrong.

Thanks,
- AlB

Have you pressed and corned your BP prior to loading it into the tubes or was it just meal powder?

If you used corned BP you haven't succeded in making 'an excellent product on a regular basis'.

Try a heaping tablespoon in the middle of a four inch circle cut from a plastic shopping sack, twist to close. Cut six pcs of 3/4 fiberglass strapping tape 18 inches long. Starting at the twist, wrap the first piece of tape around until it runs out, repeat at 90 degrees. At the end of the third tape it should be a cube, double up with the remaining three pcs. Fuse though a corner and watch out for the sides, they'll hurt you out to about ten feet. If this won't do it for you, work on your powder.

I find that BP requires more confinement than just a usual cardboard tube. I found out how to do it with a few tries; I use plastic tubes from the pharmacy, I make the fuse hole as small as possible and I glue the cap on. Try that, just remember that you need allot of confinement.

This is a cut away view of a typical homemade salute:

<a href="http://photobucket.com" target="_blank"><img src="http://i10.photobucket.com/albums/a139/maxdal/untitled-2.jpg" border="0" alt="Photo Sharing and Video Hosting at Photobucket"></a>

the BP is in a tissue at the top.

Have you pressed and corned your BP prior to loading it into the tubes or was it just meal powder?

If you used corned BP you haven't succeded in making 'an excellent product on a regular basis'.
I'm not sure what you mean by corned BP. Are you referring to a granulated black powder that's a large grain size or small ball? I milled my BP, I did not granulate it. I prefer to avoid granulation...

[QUOTE=Grapes Of Wraith]
I find that BP requires more confinement than just a usual cardboard tube. I found out how to do it with a few tries; I use plastic tubes from the pharmacy, I make the fuse hole as small as possible and I glue the cap on. Try that, just remember that you need allot of confinement.

This is a cut away view of a typical homemade salute:

the BP is in a tissue at the top.[/quote[

Hmm interesting. But have you had any success with tubes at all? And the tube I use is not simply cardboard, but some kind of improvised cardboard that seemingly will not burn...

Also why do you put the BP at the top like that, ontop of the tissue?

- AlB

Those are the only BP salutes I've made with great success; sometimes I put gasoline in the bottom of the container and use plastic wrap instead of a tissue.

The reason for the tissue or plastic wrap (when dealing with liquids) is to hold the charge in place without it the BP would be loose in the container and wouldn't touch the fuse, also you only need a few grams of BP to make a good fire cracker so the tissue method is used instead of waisting the BP. My graphic may seem confusing so I will explain: the tissue rests on the lips of the container to make a sort of funnel, then you place your BP (typically around 3 grams) in the tissue then put the cap on so everything is held in place.

This may be of use to you: http://www.roguesci.org/theforum/showthread.php?p=45462#post45462

You might want to read the rest of the thread as well-

I'm not sure what you mean by corned BP. Are you referring to a granulated black powder that's a large grain size or small ball? I milled my BP, I did not granulate it. I prefer to avoid granulation...

Granulation is exactly what I meant by 'corned'. Avoiding the granulation process is the faulty point in your BP, as meal powder it burns too slow for use in salutes.

Most 'boomers' made with black powder are useless and are not impressive. The gasses released aren't released fast enough to be useful for firecrackers in most conditions.

Try some flash powder. 70% Potassium Perchlorate 30% Dark German Aluminum, mixed with the diaper method.

Very sensitve stuff...and you can actually leave the caps off of your cardboard tubes, and it will still be loud. Be careful, and dont' make over 100 grams, or you'll be asking for it. I personally made it in 100 gram batches, and realized how powerful it is, and if that whole pile went off, what it could do to me, and my shed that I do my pyrotechnic stuff in.

The Fire Crackers I described are not very powerful, but anyone who sees one explode will think otherwise. They look and sound very powerful but when put to a test, they fail. Aren't they for show anyway; If you wanted high performance explosives you wouldn't use black powder or flash powder, right?

When I make small explosives with BP I use practice golf balls. Which makes a good explosive if they are made right. I don't press the BP cause I find it works fine without it. I just drill a small hole in them and use a funnel to fill them and then put cannon fuse in. For a good seal get some high grade gasket maker. After the gasket maker is dry wrap the golf balls in duct tape for a better bang.

BP salutes are easy to make with a good screw cap bottle, ive experimented with a 50ml screw cap pill bottle. Using standard visco through a hole in the top and some random BP i had it worked well.

AlB, It seems like you are essentially trying to make a bp pipe bomb. If that be the case, I would suggest that you go for a stronger casing. Something like PVC piping works well, but you have to make sure you have secured the end.
Unfortunately with a stronger casing comes a higher risk of shrapnel, and so be sure to take proper precautions with whatever you do.

The link I posted above leads to a description of a traditional cubic BP maroon from the days before the availability of cheap Aluminum and Magnesium metal powders, with only paper, string and glue forming a very strong containment. Never use metal to contain explosives unless you are INTENDING to fabricate a weapon for hurting people, not a firecracker to entertain them... PVC and other hard plastics are not much safer.

Crap, I suppose I should just post photos of constructing one of them, a picture would help those among us who can't read English too well.

Hi AIB,

Tomu is right, normal black powder manufacture requires granulation of the powder after milling. This is an important step. That's not to say you cannot use the milled powder for certain applications but as a propellant or charge it is important to granulate. Popular theory states that the small grains allow the flame front to easily propagate through the charge, resulting in a dramatically higher burn rate.

The webpage over at http://www.pyrotechs.org/dwilliams/blackpowder/blackpowder.html has a good description of producing black powder, including granulation. The method on the aforementioned page will produce hard grains that resist collapse. Where this is not needed (in many applications) granulation can be achieved without the press by adding a bit more water and 1.5% dexrin (well, for ease say 1.5 g to 100g composition) and simply using a mallet.

A simple web search, you can find things.:rolleyes:
Corned BP

http://www.vk2zay.net/composition.php?id=3

AIB, everyone has there own ways of making BP salutes based on whats available to them (even knowledge). So what is available to you, in terms of casings or other parts?

After granulating BP, try making a polumna. They are made by getting a sheet of newspaper, folding it into a thin strip and then folding it up in a triangle with a pouch of black powder on the inside. A fuse is inserted before folding.

Very easy to make, hope this image explains it clearly. Make quite a nice bang because of the confinement.

http://i5.photobucket.com/albums/y171/evilgecko_nz/BPPolumnaConstruction320x240.jpg

After step 4 continue folding up and secure with piece of sellotape.

Very easy to make, hope this image explains it clearly. Make quite a nice bang because of the confinement.

While I have never tried using black powder in polumnas, I have read that it doesn't always work due to black powder not deflagrating rapidly enough. I will try it though. Nice, easy, and fast to make :D.

Thank you everyone for your replies..I will check out all these ideas.

polumnas are good if you use flash but fast bp made with balsa works well also, after you fold one dip it in PVA glue (elmers) as this gives it some waterproofing and adds strength to it.

Quite frankly, the use of BP for crackers will teach very professional construction simply because it is a high gas ensuing composition and the containment needs to be quite good for that to produce a report.

A PGII workshop on the original method of producing "old time" Asian crackers advises the use of BP as it is not easy to wrap a good cracker from newsprint and make a fuse from rice paper. When you have make one that produces a reasonable report, you are making the tucks and rolls in an appropriate fashion.

Literally anyone can put together a reasonable flash cracker. But to do so with BP takes some skill. That was the consensus and actually those imported into the US some decades ago were BP if they came from China and were made for celebratory use by the Chinese themselves.

There is a really wonderful book on this subject (perhaps one of the very few) written by Moyer; Firecrackers: a History: well worth buying as it traces the manufacture, the swing to flash, the history of flash, the use of BP and the construction of braided crackers and the braiding and construction over the last century; as well as the tools and techniques utilized therein.

Well...Ive looked around at the links provided, and unfortionately to me I have no hydralic press sitting in my garage, so I guess I will use something like an 8% solution of water and pass my bp through a spaghetti strainer or something...

By the way, since someone asked, I do not have a lot of random stuff sitting around, but I can always stop at home depot or my local hardware store. I have experimented with PVC and although the ensuing "BOOM" is quite satisfying, it's hardly safe enough to be doing around people other than myself.

Did you ram the BP? The tube should be about 3/4 full of BP.

Also, BP would not work good in those, unless you have some FAST burning BP.

After I ran out of 'firecrackers' on the 4th and still had a bunch of homemade BP left I started improvising and was quite impressed.

I have a 2 inch piece of steel pipe with a small hole at the bottom for a fuse welded to a base to use as a mortar for shooting mines (stars on top of some BP so that it shoots the stars into the air for a nice effect).

I put about 2 tablespoons of BP (meal powder with water added and forced thru an old window screen) in the tube with a little newspaper on top. Pretty nice boom.

I then tried (well away from others) about the same amount inside a coke can. Put a fuse in the top and taped it in place so that as it burned past the tape it would fall in the can. Even better boom. I was using BP that I consider slow compared to other that I make and it still did pretty well. I know about the shrapnel thing but it blew the can into about 4-5 pieces and maybe flew 10 feet (light and large surface area so not much momentum and lots of air resistance). I had some cleaning to do the next day but they only took a few seconds to make and everyone thought they made a nice deep boom.

When I make firecrackers with BP or SP (just for the heck of it) they ONLY work when I put a wad of packed tissue paper in the fuse end of the tube, and bend the fuse around the wad so that when the flame reaches the powder, the pressure pushes the wad against the end of the tube and creates somewhat of a seal. When I don't do this they usually just shoot a flame out of the fuse hole and don't explode.

I stole this idea from somebody here who uses it in his BP pipe bombs.

When I fill my polumnas with SP they usually make quite a nice bang, so I think using BP should work. I'm gonna try it once I get more KNO3.

When I don't do this they usually just shoot a flame out of the fuse hole and don't explode.

The BP in that example is then too slow. The relationship between the need for completed enclosure is proportional to the speed of the deflagrant.

A deflagrant is deemed too slow if the ensuing gases seep from an opening. Were it fast(er), the gases would build quicker than they would escape and you would hear a report. That's Weingart 101.

Maybe I'll try granulating my powder...

Do you know how I could do this without a sieve? I don't have any window screen or anything similar right now.

There are a variety of factors that contribute to speed of deflagration. Particulate size being perhaps the easiest & simplest to control. If the size of the material is smaller to begin with and you maintain the proportions best suited to the resultant usage, you will be successful.

With BP the 75:10:15 ratio is perhaps the most common. However the idiosyncrasies of the type of C has some influence. {See "coca Powder", "Willow", Coal, etc}

In addition the reduction of particulate size (BOTH prior to & after combining) may be affected by the use of a coffee grinder, ball mill, & high quality mortar & pistil. In this context the "whetting" prior to mortar & pistil use has proven to be very flexible as deflagrants of a higher burn rate potential than BP may be experimented with.

My conscience is telling me to stop spoon-feeding so I'll leave this alone and refer you to Wiengart. That's where you really want to start. Study, memorize, & study some more. Use the study skills you would apply to anything else.

There is a neat trick with the menu on this board. I don't want to give away a secret but click on the part that says "search".

Maybe I'll try granulating my powder...

Do you know how I could do this without a sieve? I don't have any window screen or anything similar right now.

If nothing else, you could try splattering a thick paste of wet black powder on to an appropriate surface, then removing, and further crumbling the chunks afterward. I've used this method with some success.

Charles Owlen... Not only do you seem to spoonfeed a lot, but go overboard with stating the obvious. It doesn't take a rocket (or indeed any other) scientist to determine that a faster burn rate will make a better explosion.

Not that you haven't been a great contributer to the forums lately, and I don't mean to flame, but it needed to be said.

What's obvious to us is black magic to a n00b.

Charles Owlen... Not only do you seem to spoonfeed a lot, but go overboard with stating the obvious. It doesn't take a rocket (or indeed any other) scientist to determine that a faster burn rate will make a better explosion.What's your prob? I don't know this guy from Jack, but he's contributed more in any five of his posts than the whole of some peoples so-called "contributions".:rolleyes:

Out of all the choat-soaked posters that DO need dressing down, you pick one of the few who has shown to have something to offer.:confused:

If you don't like the posts, put him on your ignore list, for chrissake.

As a tip, I find that when making a polumna or similar cracker, it helps to put a bit of masking tape around the visco fuse leaving about a cm of it exposed at the end, and aligned such that the fuse becomes exposed when it is at the centre of the powder. This finds particular use with sulphurless black powder, which is frequently weaker than ordinary BP. I imagine that the effect is due to the ignition, having originated at the centre, being able to ignite more of the powder, and faster, before bursting the containment.
I also find that newspaper is far inferior in the making of a polumna; rather, ordinary paper or some sort of thicker paper is preferable.

I used to do that when making "cherry bombs" when I first became a pyro.

About half a centimeter from the end of the fuse, I would wrap just enough electrical tape to keep the fuse from burning through it. I would then stick this in the hole down the center of one those pre-made pyrodex nuggets (for muzzle loaders) so that the exposed end was in the center of the nugget. Then I would just wrap the thing tight in about a centimeter thick layer of electrical tape.

BP salutes are easy to make with a good screw cap bottle, ive experimented with a 50ml screw cap pill bottle. Using standard visco through a hole in the top and some random BP i had it worked well.

I use the same technique but using "mountain dew" bottles. Just put some bp in bottom of bottle punch a small hole in cap to put fuse in. Screw on cap and stand upright and as the fuse burns it will fall into the powder.

I don't know if this has been touched on before, but I too have experimented with loose black powder in a plastic screw-top bottle and inevitably found the system's flaws. While having the powder spread out over a large surface area on the bottom of the bottle allows slower, perhaps fuel-rich powders to burn up more quickly, ignition is iffy unless the bottle is upright on a flat surface. Also, if travelling (as I have experienced), black powder tends to separate. If a plastic bottle is still the desired casing, the best remedy is to contain the powder in a smaller container suspended from the fuse, inside the bottle. As the fuse burns down, the smaller container will drop down to the bottom of the bottle if upright, or if not, it won't really make a significant difference. The smaller container limits the mobility of the powder, preventing seperation. One drawback is the possibility of the fuse ripping from the weight of the suspended container.

I have tested and messed around with KNO3 based flash powders, however my favorite is KMnO4 for the oxidizer.

I posted this on De Rerum Omnis originally, but its not very well known yet, so I thought I would stick it here, as these crackers are easy to make, pretty obtainable materials and make a hell of a bang.

4 parts potassium permangante
1 part Al 600 mesh+
.5 part sulfur.

Make sure you grind each ingredient well for better ignition, this mix is not very flame sensative, its pretty safe to handle, not very sensitive in my opinion. Run it through a sive to catch any larger pieces.

This mix I use for firecrackers. Most people go to quite a lot of trouble to make firecrackers, buying casings and endplugs....it all adds up, if only they realized they could get a couple hundred casings and endless endplugs from the hardware store!

cut a piece of clear vynl tubing (depending on the size of the cracker you want). I usually cut them about 4 cm long, this allows for a gram or so of the above flash mix. Fill one end with hot glue (about 8mm) and let it harden, then pour in your flash mix pressing it down (don't be afraid to use force, this stuff isn't AP)

Once that is done stick in a piece of fuse, wad up a bit of tissue paper and stuff that down after, then fill the remaining bit with glue. there you go! A super easy firecracker that packs a punch made in about one minute, I make around 30 of them every Halloween, but I have a friend helping.

I'm sorry totenkov, but aren't KMnO4-Based flash powders not recommended because of their extreme sensitivity? maybe I am wrong but, I do remember reading it somewhere.

All sorts of things are "not recommended" and the point of that recommendation or the lack thereof is (in terms of the use of same) in commercial or hobby compositions. If one is aware of the risks then one should be aware of the pit falls.

Actually there are several reasons why KMnO4 could be less desirable than other oxidizers quite aside from sensitivity. But it DOES provide a source for an easily available oxidizer when CPSC has closed all legit sources of KClO4, etc.

Ive had lots of success with black powder salutes, all i do is mill my pine pb for 24 hours, granulate it and its ready. If your using tubes dont make them too thick or the plugs may get pushed out, use 1/16" thick tubes and for the plugs make 1/4 inch layers of hot glue. Works for me =)

Milling the black powder ingredients in the tumbler for only several hours will result in a slower burning meal that is suitable for rockets.

Milling for several days, or more, will produce a very fast burning meal that will not separate easily and will indeed make a quality firecracker. Ricing of the powder (moistening and pushing through a screen, as a kitchen strainer) will produce a less dense grain (than corning) when dry that is very fast burning also.

Home made charcoal is best.

The tubes for the crackers can be any sort of paper strip about 1 1/2 to 2 1/2 inches wide and about 18 to 24 inches long that is tightly wound on a pencil and glued at the end flap to finish it. One end is then either crimped and tied with strong string to close it, or the inner folds of the tube can be pushed in from at least three points to create a plug and then covered with glue to hold it in place.

When filling the tube with meal powder, only fill it loosely about half to three quarters full. Then insert the homemade fuse (tissue paper strip sufficiently long lined with moist powder and carefully rolled and twisted into a thin fuse about 1/8 inch thick then dried) into the open end and crimp and tie or push in the inner folds of the tube to make a plug around the fuse. Smear a little glue on the plug and the resulting cracker will be similar to the chinese style.

When it has dried it is ready. The black meal powder cracker will produce a nice report and blow the tube into small pieces. To sharpen the report mix some aluminum powder into the recipe, by weight:
9 parts potassium nitrate
2 parts charcoal
1 part aluminum powder
1 part sulfur

or by volume:
4 parts potassium nitrate
4 parts charcoal
2 parts aluminum powder
1 part sulfur

If desired, or if not available, the sulfur can be eliminated.