135 replies to this topic

[RegimentalPyro]

OK guys - Many apologies if I'm asking questions that have been answered in an earlier thread - I have searched - honest.

I'm fairly new to this hardcore pyro stuff [only having set off a few medium sized displays], but would like to get a little more experienced. To that end I am going to have a go at what seems to be one of the more basic tasks - Making damn good BP [BlackPowder]

Ingredients

KNO3 [Potassium Nitrate?]
S Sulphur
C Charcoal

Instructions=Mix ingredients well and put through a ball mill to make it as fine as possible.

Onto the Questions!
This seems too simple - What have I missed?
There seem to be various different mixes that are referred to as "comps", [composistions?]. What is each mix used for?
Say a comp specifies 75 KNO3, 15 C and 10 S. Should I measure by weight, or by volume [scoops]
What's this ricing process I keep hearing about? Is it anything to do with adding rice hulls? Why is it needed
Is "meal" another name for BP
Is there a risk of ignition during the milling process as it relies on friction. Should milling be done indoors?

Any info/safetytips you can throw my way would be appreciated.

Thanks in advance!

[Pyromaster2003]

ok, no you havnt missed out realy. milling media in mill mix the ingrediants by weight and not volume (75grams/15grams/10grams) and them pour into the mill and set milling for 3 hours or more. when its finished simply empty the media and BP into a sieve to collect the media and let the BP fall through on a sheet of newspaper. Thats BP, the good stuff. thats how its made commercialy so no, there are no dangers of ignition through milling. UNLESS ofcourse you use steel balls which may spark and ignite the BP, so always use lead media, 1 because there heavy and 2 because there non sparking.

yes there are different comps for different applications. for example the normal BP could have added to it say chunk of charcoal and Al to creat nice orange and silver long lasting trails in a rocket or fountain.

ricing is about compressing the powder with around 2 tones of pressure to make it into a solid, this is then broken up with a mallet to get different grades of BP for lifting,exploding,coating (coating rice hulls in BP creates BP coated rice hulls(surprise surprise) and these are used as the explosive in shells). meal powder is the finest BP.

[phildunford]

Really good info about making black powder at

http://www.wecreate4...lackpowder.html

I find his info about how much moisture to add a bit suspect, but it is a good place to start. Plain milled powder is fine for a lot of things, but for maximum power you need to granulate the powder for fasted burn rate. this is an extra stage and one I am finding a bit tricky. Grains of commercial black powder won't crumble between your fingers, but mine does at the moment. I think it's all to do with moisture content...

[Pyromaster2003]

o brilaint Dan William's pages are back up and running.

[bernie]

'Ricing' is the process of wetting down an amount of black powder composition with say 20 - 25 % water, forming a ball and scrubbing it through a window screen. It should resemble to some degree black rice. In some cases it is used with other compositions as well. Because ricing forms soft little grains it flows very easily in a funnel and is cleaner to work with than a powder. Meal tends to cake up in a funnel and flies all over the place.

'Corning' black powder is a different animal. This process results in very hard sharp edged granules that very much resemble commercial black powder. (Commercially produced bp goes through the additional steps of rounding off these sharp corners and is dusted with graphite by some manufacturers.) An amount of water ( 6 - 10 % depending on the pressure used ) is added to some good meal and pressed with considerable force into a thin cake or puck say 13 mm or less. After it has dried it is broken up (looks like cracked corn )and run through sieves to grade the sizes of the granules. Hint: the pucks or cakes should sound like ceramic discs when struck against one another.

Milling should be done outdoors.

Meal powder is a very fine black powder flour. Finer than talc. Only black.

Compositions refer to almost any 'mixture' of ingredients used for pyrotechnics. Star comp, rocket comp, fountain comp etc.

Did we miss anything? We are here to serve.


[Edited on 30-7-2003 by bernie briden]

[Edited on 31-7-2003 by bernie briden]

[Pyromaster2003]

now i have a question now on the subject...how much better is compressing with a few thousand pounds of pressure than simply moisting and pounding with a mallet the black powder into a puck?i done it the other day nad it turned out pretty good.

[bernie]

I would think that density has something to do with it. There's a sweet spot. No binder is used in commercial powder that I am aware of. It must be a mechanical bond?

The short answer is "does it compare with the commercial standard?"

The other answer is whatever serves the purpose.

If you make some bp lift for a shell and the grain is on the soft side but will do the trick then there are no worries. If the lifted shell is going to be bumped around and the grains crumble then you have impacted it's performance.

A standard or benchmark is handy to have.

The very best information I have ever seen on this is published in one of the pyrotechnica series. I can't recommend it enough. You won't be sorry if you spend the money.

[phildunford]

If you compress the powder using some sort of press, the ideal density is supposed to be 1.7g per cc. I'm sure the bond is purely mechanical.

When you break it up into grains and seive it to grade it, it's difficult not to end up at a powder again. Dan williams method is to pound it gently with a baseball bat (!) but I have heard of people making a crushing machine to get a more consistent result.

[bernie]

Three and a half % seems about right. Some people use more. The pump needs to be very sturdy to withstand all the pressure that is required or the walls expand. What kind of pump are you using Phil?

[Edited on 1-8-2003 by bernie briden]

[RegimentalPyro]

OK - It looks like I've actually managed to do it.

On Saturday morning I started casting my milling media successfully. [Lead balls 0.580 inches in diameter made with with a bullet cast]. By midday I had enough to start milling.

The KNO3 was already fairly well powdered as was the Sulphur, but I took a lumphammer to some ordinary lumpwood charcoal from the garden centre (trouble getting willow charcoal) to get it down to something approaching a powder - still a few lumps, but I relied on the ball mill to get those out...

Measured out the comp (75/15/10) as carefully as I could. and put into the ball mill with the milling balls. Left running for 3 hours outside, but in the shade.

When I opened the mill up I found a fluffy grayishblack powder - The BP meal.

I recited the Pyro's prayer with a fervent look upon my face and applied a flame to a small pile of the stuff causing it to flash and fizzle.

I have now smelt the smoke and can never be free! <grin>

Making the pile into a line allowed us to make the fizzle follow the line (a la tom'n'jerry cartoons). Funnily enough this is what most people I bragged shamelessly to, wanted to see...

I guess my next step is gonna be ricing the meal or making black match. Anybody got any top tips and/or tools for these tasks?

[Rhodri]

Charcoal

You'll only get a mediocre powder using lump wood charcoal. It won't lift too well.

I (and others) would suggest using a soft wood charcoal.

Balsa wood or Willow (from an art shop) when ground down will dramatically increase the burning rate of your BP.

Good lift BP should (whoosh, almost thump) when ignited.

You really should try this - you won't go back to BBQ C once seen....

[BigG]

OK - It looks like I've actually managed to do it.  

On Saturday morning I started casting my milling media successfully. [Lead balls 0.580 inches in diameter made with with a bullet cast]. By midday I had enough to start milling.

The KNO3 was already fairly well powdered as was the Sulphur, but I took a lumphammer to some ordinary lumpwood charcoal from the garden centre (trouble getting willow charcoal) to get it down to something approaching a powder - still a few lumps, but I relied on the ball mill to get those out...

Measured out the comp (75/15/10) as carefully as I could. and put into the ball mill with the milling balls. Left running for 3 hours outside, but in the shade.

When I opened the mill up I found a fluffy grayishblack powder - The BP meal.

I recited the Pyro's prayer with a fervent look upon my face and applied a flame to a small pile of the stuff causing it to flash and fizzle.

I have now smelt the smoke and can never be free! <grin>

Making the pile into a line allowed us to make the fizzle follow the line (a la tom'n'jerry cartoons). Funnily enough this is what most people I bragged shamelessly to, wanted to see...

I guess my next step is gonna be ricing the meal or making black match. Anybody got any top tips and/or tools for these tasks?

Flash and fizzle?!?! That does not sound good. It should burn quickly, not fizzle. A train of about 45 centimetres should take anything between 0.3-1.5 seconds to burn from start to finish, and should leave very little unburned material behind. Is that what you got?!?!

BigG

[RegimentalPyro]

Hmmm - think my initial joy was somewhat premature

The stuff I've got seems to burn fairly clean, but does leave behind some droplets of "slag" that cool from a glowing red, to pale yellowish, before rapidly turning white as it completly cools.

I've not done any quantitive speed tests yet but I will tonight. I'll post the results.

Anybody else got any good ways of assessing the quality of BP?

[BigG]

There are ways of assessing BP, but you don?t need to get to that level just yet. You will know when you got fast burning BP. The 45cm will disappear too quickly for you to follow. There are few places where you might went wrong. The first is your charcoal. It could be not of good quality, and with large percentage of ash ? that will slow things down dramatically. Also, it need to be very fine to start with (before put into the ball mill).

The second problem might be with your measurements. How did you measure 75-15-10? Using volume or weight?

BigG

[Rhodri]

Personally, using Gar. dir. KNO3 I can make FAST BP. It does take a bit of effort though.

RegPyro - change you charcoal to Willow (as mentioned, you can get this from an art shop to draw with). Mill this down. Then weigh 75g:15g:10g (03:C:S) and mill.

You'll then see what we're on about!


PS. I'll even send you some Willow C if you can't get any - it makes THAT much difference.....

Edited by Rhodri, 11 August 2003 - 03:19 PM.