196 replies to this topic

[Bonny]

Poplar makes insane BP, much faster than willow imo

I might give that a try although willow has worked well for me so I'm reluctant to change. Any particular type of poplar? The yard and forest at the family cabin is loaded with black poplar,paper birch,and a few types of willow. I'm curious if anyone has ever tried Tamarack (larch) tree ? The wood burns very hot and smells great too.

[they say im crazy]

hey there sort of straying of topic but not much,
i was milling my bp the other day with lead media now, after about 8 hours i checked progress by opening the container and all the powder was compressed at the bottom of the jar ( i dont know why it was the bottom but hey) so does that mean its done? or should i keep milling? i heard about milling for 2 days which i can do no problem any ideas
oh forgot to say i made powder like this before and wet it into a paste and forced it though a seive and dried it, the burn rate improved alot but i heard of putting the granuels in a ball mill with no media to "polish" the grains also do you reccomend dextrin as a binder when i seive the powder? (would it make it a better quality powder) and how much dextrin per grammage of bp should be used

Edited by they say im crazy, 25 November 2007 - 09:00 PM.

[seymour]

Polishing grains is usually done with pressed and corned grains, I doubt it would do anything to riced BP except break up the grains. Dextrin works ok for ricing BP, it will be better than using no binder (It works) which is what I did three years ago.

I have also had all my BP clump in one end before, which I am sure had alot to do with the high humidity, and also that by that stage the BP was pretty well milled, in any case it was fine enough to be perfectly usable. If you are worried that it is not milled enough, why not break it up, perhaps dry it and keep milling?

[Techohead]

well since i started this post a month or two ago, i have made remarkable procress. with ten hours milling time, then ricing/corning and drying i'm getting a burn rate of 105cm/s which i believe is just less than half black powders maximum potential which is said to be reached with about 24 hours milling time. you must realise that the milling does much more than making teh powder fine. after about 3-4 hours the powder will be as fine as it will ever get (airfloat) and the additional milling time is to compress the particles of the different atoms together tighter, making them 'chemically' bound, rather than just 'physically' bound. this means that once the chemical reaction is started, the atoms are already in contact with their reactants, making it a quick and quick spreading reaction/faster burning powder. if you are using a homemade ball mill then your times may vary substantially. i recommend milling about a 200 gram sample, and every two hours take a sample out, and label them. run the mill for up to 30 hours or longer, or until the separate samples no longer differ in speed.

as for the powder clumping when you look in your mill... the mixture shoudl be completely dry when you put it in, and while running it shoudl sound like a constant 'pitter patter' like raindrops on a tin roof. if the powder is clumping or your mill is inproperly loaded, it may sound like groups of clinging, with a silent part of each revolution. it is perfectly normal for teh powder to clump slightly when not moving, as it is soo fine this is in it's nature. once finding the length of milling time with the greatest burn speed, corn with dextrin and water. there is plenty of information to be found on this so don't ask on this thread.

hope i have helped with your questions regarding milling proceedures and such, and that this substantial post of mine has been informative to you all, as i have gained soo much from the joined knowledge of peopel on this forum, and intend to return the favour.

[they say im crazy]

thanks its been milling for about 12 hours so far so ill leave it for another 12 hours i will bind with dextrin and see if it is beter than just corning alone

[Techohead]

i add my dextrin into my mixture before milling, which means by the time you corn it, just add water. means your going to have a perfectly even consistancy.

[marble]

With reactive charcoal and a hexi milling barrel I can make damn fast meal in 45 mins, its much faster than my meal made with my old ball mill which I used to mill for 14 hours in a round barrel.

Pulverone is even faster

Edited by marble, 26 November 2007 - 10:46 AM.

[Techohead]

well today i did my speed test... the results for which i've long awaited, but were somewhat inconclusive. i laid out 2 grams of powder into 2 X 50cm lines, one with my 12 hour milled powder, the other with 20 hour. i lit one with a match, then a few minutes later lit the other. they seemed perfectly the same, and apon precise computer video analysis, i proved that the 12 hour powder burned 50cm in 1.2 seconds, the 20 hour powder burned the same length in 1.15 seconds. where's the additional 8 hours factor into it? calling all pyros that know a bit about milling. two theories of my own: perhaps the powder has not been corned, so the burn rate of uncorned powder is almost a constant... or... perhaps i have reached a potential limit of some kind, maybe my mill cannot achieve any more efficient powder for some reason, or it is confined by the materials i am using. please advise.

[Bonny]

well today i did my speed test... the results for which i've long awaited, but were somewhat inconclusive. i laid out 2 grams of powder into 2 X 50cm lines, one with my 12 hour milled powder, the other with 20 hour. i lit one with a match, then a few minutes later lit the other. they seemed perfectly the same, and apon precise computer video analysis, i proved that the 12 hour powder burned 50cm in 1.2 seconds, the 20 hour powder burned the same length in 1.15 seconds. where's the additional 8 hours factor into it? calling all pyros that know a bit about milling. two theories of my own: perhaps the powder has not been corned, so the burn rate of uncorned powder is almost a constant... or... perhaps i have reached a potential limit of some kind, maybe my mill cannot achieve any more efficient powder for some reason, or it is confined by the materials i am using. please advise.

As long as the powder is reasonably fast it's fine. When making meal powder I'm sure after a certain amount of time, powder will be as mixed and crushed as it is going to get, with minimal improvement acheived by longer milling time. Fine meal powders leave very little space between particles for flame to rapidly pass through. After pressing (if you have a press) and corning, or just corning it will be much faster. What I am most concerned about personally is consistency and have never even looked at speed.

[Techohead]

but would my samples have had a bigger variation in speed if they 'had' been corned?

[marble]

Corned powder burns a tad slower compared to pulverone, meal is even slower.

Edited by marble, 29 November 2007 - 09:46 AM.

[MDH]

That really depends on your black powder. Overoxidated powder will burn very quickly if pressed for instance, which is why it is often used in black powder firecrackers. With perticular charcoals underoxidated black powder will as well (Balsa green mix).

[Bonny]

but would my samples have had a bigger variation in speed if they 'had' been corned?

That's very difficult to say. A good starting plan for consistancy would be to use the same ingredients and same milling time. Although pulverone is apparently faster, pressed powder is supposed to be the most consistent.If you make several batches (either of pulverone or pressed and corned BP) mix them into a master batch and test that. This should even out slight deviations in performance, yielding a more consistent powder. I don't even test batches anymore. I press, corn,sieve, and then weigh my charges for what I am doing. For my 1" cylinder shells I have consistently used 5-6g from many different batches of BP and all have performed to satisfaction.

Do you have a press?

[Techohead]

no i don't have a press, or the tools to build one. However i can achieve pretty good results just 'ricing' i belive the term is. (adding dextrin, wetting then sieveing and drying) yesterday i laid out a few grams in a long thin line to test the burn speed. apon video analysis concluded that the burn rate along a line is 136cm/s. seems fast enough?

[Bonny]

no i don't have a press, or the tools to build one. However i can achieve pretty good results just 'ricing' i belive the term is. (adding dextrin, wetting then sieveing and drying) yesterday i laid out a few grams in a long thin line to test the burn speed. apon video analysis concluded that the burn rate along a line is 136cm/s. seems fast enough?

I've never done any burn speed tests as I don't think they can be controlled well enough to accurately measure...too many variables (thickness,width of BP trail,air space between grains,grain size etc) I did my testing by lifting shells. Anyway, try using to lift (dummy) shells, comets or in mines, then dial in the height you want.