Grey Powder?

[usapyro]

So, I was kinda lazy on checking on my ballmill full of BP and busy with other things so I kinda let it run for a couple days or so. The powder now looks more silvery-grey instead of black. It sticks together and clumps as a dry powder. It also nearly burned my eyebrows off when I lighted some of the meal as a test. Woah fast...

 

I have heard you can over-mill your BP and it loses speed... But, I dunno about that... This batch of two day milled willow BP for new years shells is the fastest I have ever made!

 

I have a theory that if you use around 7mm lead balls it's very hard to over-mill your BP and hurt the speed. If you use a larger size of 10mm+ you will have harder impacts that can over-grind your powder easily. Any thoughts?

[Sabdacrab]

I found the exact same phenomenon, nowadays i mill mine purposely until its clumpy and doesn't flow freely like meal. It does wonders for break!

[NightHawkInLight]

I don't believe you can over mill BP. You can over press it, but not over mill it. My milled BP is always grey. I take that as a sign that all of the components are equally as fine and intimately mixed, rather than just the black charcoal coating everything else.

[athlon]

I was also surprised when I did my first batch of milled BP, it was grey as opposed to black when I've done it the CIA method way. Way better performance in the milled stuff also.

[Mumbles]

Anyone who says you can over mill BP is full of it. All of my BP once done will clump and is a grey exceedingly fine powder. A small sample burns with a little pop almost, and doesn't scorch even a bit of the paper.

[pyrogeorge]

My Bp is always grey and i mill it for 1,5hour.It is very fast,i lift from 2" to 6" shells with no problems

[usapyro]

Btw, has anyone here ever heard of Brown Powder? It is from baked wood... A specific temperature somewhere before charring.

 

I was reading that it is friction sensitive. That kind of would make sense as you can rub two pieces of wood together and start a fire. However, the whole thing might just be a bunch of bs rumors. Not sure. :/

 

 

My Bp is always grey and i mill it for 1,5hour.It is very fast,i lift from 2" to 6" shells with no problems

 

Mmmph... You must have a very nice ballmill to get grey BP in 1.5 hours.

[Potassiumchlorate]

I mill for 3 hours. It's grey and clumps. I use 6 kilo brass cylinders for 1-1.5 kilos of composition. The cylinders are about 20 mm long and 15 mm in diameter.

 

I think Brown Powder is from undercooked charcoal, if we are talking about the same Brown Powder.

Edited December 31, 2011 by Potassiumchlorate

[TheArchitect23]

Mmmph... You must have a very nice ballmill to get grey BP in 1.5 hours.

 

I personally can get grey powder in around 2 hours in my small mills. 1 Lb per batch. * lead media, anonymity hardened *

i think if you can get your RPM, diameter of media, and volume of media correct, there is no reason why a monster truck mill or a rock tumbler cannot make the same quality BP in reasonable times.

 

my 2 cents

Edited December 31, 2011 by TheArchitect23

[usapyro]

Yep, now does anyone know if brown powder is actually good for anything or superior to BP for any way or purpose?

 

I think Brown Powder is from undercooked charcoal, if we are talking about the same Brown Powder.

[dan999ification]

brown charcoal is said to yield a higher volume of gasses per gram becase it effectivly has more fuel to give, i have some "brown" charcoal that will certainly catch fire quicker than fully cooked/black charcoal but im not convinced the difference is relevant to our needs when it comes from the mill caked in 3 hours anyway, you would in theory use less but i dont want my bp getting lost in the lift cup and quite often put a bit more for good measure anyway, trying to cook batches of perfectly uniform "brown" charcoal is also out of reach for the most with only basic set ups, which is another reason why i abandoned testing it

 

then there is brown powder or cocoa powder [ a bp made with rye,straw?] , not to be messed with for pyro needs due to its extra sensitivity, even igniting in hessian sacks when opened apparently

 

optimum milling is what gets you fast bp fast, mine cakes in 3 hours but only with pre milled c and s after the fluffing has happened.

 

 

dan.

[pyrogeorge]

Btw, has anyone here ever heard of Brown Powder? It is from baked wood... A specific temperature somewhere before charring.

 

I was reading that it is friction sensitive. That kind of would make sense as you can rub two pieces of wood together and start a fire. However, the whole thing might just be a bunch of bs rumors. Not sure. :/

 

 

 

 

Mmmph... You must have a very nice ballmill to get grey BP in 1.5 hours.

 

[AdmiralDonSnider]

While I realize that powder color is a variable changing with integration, I just wanted to toss in that the density of a charcoal and thus the volume it takes compared to the other ingredients does alter the color as well. Balsa or Willow will make a blacker powder than oak, paulownia a blacker powder than alder. Color is not necessarily linked with performance. Edited December 31, 2011 by AdmiralDonSnider

[dagabu]

My Bp is always grey and i mill it for 1,5hour.It is very fast,i lift from 2" to 6" shells with no problems

 

Same here, 1.5 hours is plenty of time to mill BP as long as the ingredients are ready for milling, 80 mesh charcoal, airfloat KNO3 and good sulfur. If the KNO3 is prilled, it takes longer.

 

2% dextrine and 1% CMC makes for nice hard grains when whetted and screened.

 

-dag

[pyrojig]

Same here, 1.5 hours is plenty of time to mill BP as long as the ingredients are ready for milling, 80 mesh charcoal, airfloat KNO3 and good sulfur. If the KNO3 is prilled, it takes longer.

 

2% dextrine and 1% CMC makes for nice hard grains when whetted and screened.

 

-dag

 

I prefer to pre mill the chems separately to a air float, then screen mix together, followed by milling for a few hours. It makes for an amazing fast powder.

Admiral is absolutely correct about color (of the ending meal) not being a indicator of speed. I have made many diff types of charcoal, and each has its qualities, colors, and densities. Some of the lighter fluffier seem to make the hottest bp IMO. The color changes with the type of charcoal. I have one poplar and one willow that you can plainly see the diff in color, but the speeds are very close and rock'n fast!!!

I too do not believe that bp can be over milled. It reaches a point where it can not get any more reduced , at that point it is just a case of wasted energy to mill past that point .

[Mumbles]

While I realize that powder color is a variable changing with integration, I just wanted to toss in that the density of a charcoal and thus the volume it takes compared to the other ingredients does alter the color as well. Balsa or Willow will make a blacker powder than oak, paulownia a blacker powder than alder. Color is not necessarily linked with performance.

 

That true, but within a single charcoal source, I've found that properly milled BP will be a lighter color than unmilled. If I make polverone from commercial hardwood charcoal it is quite black. It I mill it for making glitters or inserts or something, it comes out noticeably grey.

 

If you want to know more about brown or cocoa powder, look in Davis' COPAE. He discusses it. I don't think it's really of much use to us. Slower, and more sensitive are pretty much the two properties we do not want.

[Peret]

If you want to know more about brown or cocoa powder, look in Davis' COPAE. He discusses it. I don't think it's really of much use to us. Slower, and more sensitive are pretty much the two properties we do not want.

Cocoa was designed to be slow. They used it in guns of 15 inch and larger that would have burst if the powder was the normal speed. Example from a contemporary book: 16.25 inch breech loader, weight of shell 1800 pounds, weight of propellant 960 pounds SBC (slow burning cocoa). I posted a picture of this one in the Cannons/A Few Small Canons thread and you can see the gigantic cartridges stacked up on the left. I can't imagine any use for slow burning powders in Pyro.

[californiapyro]

stars? maybe some c6-type comps made with it would leave a cool tail. just spitballing here

[usapyro]

I noticed another couple things about this well milled BP... The smoke doesn't smell as much. Also, when granulated with 3% dextrin the stuff comes out HARD... It doesn't crumble easily at all!!!