make pyrodex BP more powerful?

[The ALL-MIGHTY]

I searched the forums and I saw nothing that I thought could help me, so I thought I’d ask here.


In my attempt to make homemade mortars and shells I have found that the pyrodex substitute black powder works ok, but for flash powder charges and other shells that I wouldn't want going below 150ft the pyrodex doesn't cut it. My question is would it be wise or practical to add say 1g of flash powder to every 5 grams of black powder in the lift or break charge for the shell? Or is there another way to add something to the pyrodex to make it burn faster or produce more gas? One thing I was experimenting with was to tie and tape up the lift charge a lot so more pressure would be created before the container ruptured, also I crushed the powder up to create more surface area to burn. But I would like to just alter the powder than just waste a lot of tape. This is all for a tutorial thing on how to make homemade mortars and shells out of film containers and a heavy tube from plastic wrap. Actually the hardest thing to get is the fuse, everything else you can get for free or buy for little money. I will post the link to the file when I have it completed and refined. Any help here will end up there. Even though most people here could and probably can already make mortars I though it was a good idea, and it would help people that want to make one but have little clue on how to start out. Any help would be most appreciated!

[NickSG]

Your kind of confusing me. Is it black powder or pyrodex that you are trying to make more powerful?

You should be safe adding 1 part flash powder to 5 parts black powder (or pyrodex). Any more than that and you will blow your mortar apart. Ive never had any problems with pyrodex before, so maybe its your cannon. As long as your shell fits right in your mortar, pyrodex should have plenty of power. You might try experimenting with different mortar lengths. The longer the tube, the more the power.

[The ALL-MIGHTY]

The stuff is pyrodex substitute black powder, the same stuff you can buy at gun stores and maybe sometimes wal-mart. I called it by both black powder and pyrodex in the post, but all the time i'm talking about the pyrodex substitute black powder. sorry for the confusion.

what i would really like to know is what the hell they do or don't do to black powder substitute. That way you can add whatever they left out and make it into real black powder.

[NickSG]

Well, the ingredients of Pyrodex is unknown, and as far as I know, it is strictly a company secret (I dont know how many companies make it).

Theres really isnt anything I know of that can be added to make it more powerful other than adding a complete different explosive (fast burning of course).

[Sir Dudalot]

It has the patent number right on the front of the bottle. It's U.S. patent 4128443 Click here (http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=4128443.WKU.&OS=PN/4128443&RS=PN/4128443) At the bottom it has three mixtures that they could be using, one is mostly KNO3 and the other two are mostly potassium perchlorate (can't think of the formula for it now, I feel stupid). The only thing I can think that would make it more powerful would be crushing it to a fine powder. You could always add a little bit of AP instead of flash if you felt like it but I would stick with a finely ground powder. Also I think the mix they use is hygroscopic, when I left out some that I had crushed it tended to cake together after a day or so.

[51K]

If I understand your question, you want to get higher lift on your shells. I would try two things. First, I would cut your mortar tubes longer and then I would go with much larger diameter bp kernels. What you want is a longer time that the lift charge is acting on the shell when it is in the tube. If you have very small grains of lift charge, it will burn fast. That means it has a very short time to give the projectile momentum. Much better is to have large grains of lift charge that burn relatively slow and therefore over a longer period of time so that there is more time it is pushing on the projectile to give it momentum. The mortar tubes I lift film cans with are approximately 2 feet long and that seems to get the job done just fine. I use a heaping tablespoon of large grain bp and I would guess the film cans make it on average 100 to 130 feet. It sounds almost like a gunshot when the lift charge goes off.

I think there is really a limit on how far you will be able to lift it based on the weight of a loaded film can and the wind drag when it is traveling up. Another thing to consider is that the higher the pressure in the tube, the higher the likelyhood the shell will break in the tube.

I would certainly NOT try using anything but bp or pyrodex to lift shells or you are risking bursting the gun or the shell. A slow constant push will work every time. Very commonly the tube material is HDPE and if it is metal, you want to bury most of the gun in the ground just in case it ruptures when the lift charge pops.

If I remember off the top of my head the lift charges are calculated to be one ounce of lift per pound of shell weight up to 11 or 12 pounds and then it is an extra 1/2 ounce of lift per pound of weight over the 11 or 12. I am sure someone else here will chime in if my memory is a little foggy.

[fire vs. water]

i have tried lifting different things like tennis balls, and other balls...
I just can't get anything to shoot up above 10 feet!
i have tried so many times!

I am using homemade BP, (i made it the CIA way). The BP is made with a % more sulfur...
The grain size is fairly large... I would estimate that it is something around FFFG, or even FFG.
I tried making the grain size very small a few times, that didn't help either. My BP works fine for making salutes.... but when it comes down to launching things... it just doesn't work...

I am using cardboard tubes, which are usually a meter long. They have about 1 cm thick walls.


I tried using different amounts of BP...anything from 1 spoon to 10 spoons...but still it made no difference...

the balls fit in the tube almost perfectly...there is about a .5 cm space between the ball and the walls of the wall (EX. the diameter of the ball is 10 cm, the diameter of the tube is 11 cm)

does anyone have any idea WTF im doing wrong??

[Tuatara]

I think you'll find that 0.5 cm space is way too much. You want your ball to be a snug fit.

[A-BOMB]

.5cm is alot of room for your propellant gases to escape from try putting a 1" wide band of masking tape around the ball to remove that space or make a sabot shell and put the ball in it.

[Sparky]

fire vs. water: Give us lots of detail on your procedure and materials, then maybe we can actually help. Otherwise we can only guess really. BTW, what made you think this was the right topic for your question? This thread is really about pyrodex, not normal black powder. I think there are already topics about black powder you would have been better to post in, or just post your question in the water cooler.

[fire vs. water]

sorry...
its just that someone talked about launching things, so I thought this topic was aprropriate...

my procedure is just like what I described...do you perhaps mean how I made my BP??
excatly the way frogfot describes in his site.... only in a much bigger amount...
I made around 2 KG of BP....
When it stops raining I will try find a tube in which the ball will fit tightly, and I will post my results.
Thanks again,
Fire VS. Water

edit:
sorry i forgot to ask.... (Btw i have never encountered this piece of info. anywhere!! )
how tight should it fit into the tube?
should i have to ram\push the ball in? or should it silde in freely, with a tiny space...?

[Cyclonite]

It should be snug, if it's rammed in there you may have just made a "pipe bomb" with your launcher. As long as it doesn't take more than you pushing it with just the force of your arms it will be fine.

[bobo]

I was thinking of adding HE to BP as well. In fact, I am waiting for my BP to be dry and try it with a batch of good AP. But why would adding a HE to a propellant make it better at pushing stuff up? When I detonate a nice amount of APAN not much of the casing I use remains. My expectation was that AP/BP behaves something like APAN except it should go with just a fuse. Is this a bad idea? I would say the explosive force of a AP reinforced mixture would destroy the casing as it propels the projectile up.

[fire vs. water]

I don't think that's very wise.
HE will shred your launcher, its not as gentle as the BP...
it produces gasses so fast that it will destroy things near it.
BP on the other hand, will push the object you want to lauch...

I guess you could try adding a tiny amount, but be careful, I would recommend putting your launch tube underground somehow, incase it should explode and sharpannel will fly everywhere.

maybe adding a bit of flash powder is a better idea....

[kvitekrist]

A snug fit is essential!

I have launched coke cans filled with gravel several hunded yards, I fill the indent at the bottom of the can with homemade blackpowder and it works fine!

One trick I use is that I make a "seal" at the bottom of the can, this is made of toiletpaper and tape :)

all this and my mortar tube is only about 50cm!

[Cyclonite]

As mentioned adding AP is a very bad idea, even flash is. Flash could be used as a little booster but the main idea is to push it out not whack it out. This is the same reason why AN and dynamite is used in moving earth and not C-4. You dont want to use meal if anything get a longer launcher and a proper seal. Make your BP into larger chunks. Some may think this is unwise but in my BP production using the CIA method I run the blender with the KNO3 added as well, wet of course. Also I run it for a couple of minutes after I add the acetone to evenly distribute the crystals and keep the size small. It works great, my bp burns with a real purpose in life. If your nervous about it use small amounts with this method (I do).

[Sparky]

Yes, I mean how you made your BP. I took a look at frogfots page and it seems like as good as any way to make BP by the precipitation (CIA) method. Usually people use cold alchohol instead of acetone though. His black powder seems fairly good.

As for the fitting tightly thing, I disagree with people who say it should be tight. Certainly if you have reasonably fast BP then the tolerances you described should get your ball much higher than 10 feet. The tighter the better of course as long as the projectile isn't scraping the walls. One reason for using BP in fireworks so much is because of this property. It burns relatively fast under little pressure which means that the projectile doesn't have to fit very tight. Pyrodex on the other hand is more difficult to use in fireworks since it needs a higher pressure to burn reasonably fast, so the projectile has to fit tighter.

"its just that someone talked about launching things, so I thought this topic was aprropriate"
Well, the mods don't seem to mind so I guess it's not a problem.

Speaking of mods, I'm gonna play wannabe mod here and just let you know that signing your name after your post isn't really allowed. It's redundant.

[C9H18O6notC8H12O4]

Correct me if I'm wrong, but couldn't one test the Pyrodex by trying to ignite it with conc. H2SO4? I have quite a bit of pyrodex and it burns pretty fast, when ground to meal powder it is very grey, not black.

[Cobalt.45]

If you are using up to 10! "spoons" of BP and the tennis ball is traveling ten feet, the BP is garbage.

I suspect (please correct me if I'm wrong) that you have no scale with which to properly measure the ingredients- witness your reference to spoons of black powder.

Black powder charges are traditionally measured in grams or grains, even ounces or pounds, not spoons.

Pyro compositions are figured on a weight to weight basis, not by volume.

And, for the record, anyone adding a HE to BP expecting better performance as a lifting charge is in for a rude awakening.

A search would reveal that there are several good, well researched comps used for lift powder. Hint: Benzolift.

For fuck's sake, get a clue.

[Jacks Complete]

It's probably not the BP, it's the huge gap around the projectile. It could be the BP as well, but I figure it's doing something fast and flashy, or he would have asked about that too.