Measure quality of BP

[pyrosailor99]

Hi all!

 

i recently built my BallMill.

 

i've just finished milling my first batch.

i milled 3kg batch for 30mins. then as i understood 3kg was toomuch for the jar, i reduced it to about 2,3kg that seems the quantity i can see the last ball media surface.

 

well i milled this 2,3kg for more 2,5 hours so now i've milled that batch for about 3+ hour.

 

now i want to know how i can know if my powder is milled enough.

 

i made some test:

 

1) burned as it is.

2) burned after granulated with about 2% dextrin

 

1) give me the same result of coffee grinded powder (test made some week ago in a safe way!)... but this is what i can say from what i've seen... i can't really say if it is 10% better or worst...

2) give me the result that 0,7g of granules seems to burn in a 'woosh' (so quicker than 1) ) ... but my impression is that it is not comparable with lift charge i find under commercial aerial shell... if i burn 0,7g of this last, it burn in a greater woosh and quicker (i can't say if much quicker or few quicker)

 

a thing is sure, the powder i have now is the finest i have nerver seen... it pack it self with very easy... in a plastic container , two tap tap on the wall are enough to create deep cracks and canyons in the powder...

i think that i will not obtain a finest powder milling it further. i want to make present that, before milling BP, i milled chems separately to airfloat level.

 

so now the question is: how can i 'measure' my powder?

do your granulated powder have the same explosive power of commercial shell's lift charge?

 

how could i improve my bp if you also think my powder quality is not so good?

 

thanks

[pyrogeorge]

pyrosailor when i make BP i focus on three basic things.

1)The sound of the grinding media.You must hear the sound the media while turning in the jar.

 

2)i see my bp to has more grey powder than black..the black means not very good milling.

 

3)Test a batch.If it leave white dots means that kno3 isn't fine enough so need more milling..

 

If you have problem with kno3,try to mill it alone first for half or one hour for better results.

I hope that i helped you..

 

Also post a video of your bp test to examine it

[pyrosailor99]

pyrosailor when i make BP i focus on three basic things.

1)The sound of the grinding media.You must hear the sound the media while turning in the jar.

 

2)i see my bp to has more grey powder than black..the black means not very good milling.

 

3)Test a batch.If it leave white dots means that kno3 isn't fine enough so need more milling..

 

If you have problem with kno3,try to mill it alone first for half or one hour for better results.

I hope that i helped you..

 

Also post a video of your bp test to examine it

 

Fortunately all this items are already in my check list!

 

1) grinding media sounded to crush for the 60% of the time, then it reduced noise as i think that the jar speed (slightly higher than optimal) and milling grade of the powder make 50% of the ball rounded with the jar and the other 50% fall crushing as normal.

2) My powder have a dark grey color. i think the color is right as i've already seen the color of a good not granulated BP and it's the same. some time i wonder WHY lift charge granules of commercial shells are deep black and have a candy finish (each grain seems to be plastified)

3) fortunately the first think i wanted to notice on my first test was just the KNO3 white bubles. i'm happy as i can't see any bubble during flame and i can't see any white residual crystal after burn. so i really think i have no problem on the milling grade i've reached...

 

I have also a check list for chems and it all passed in my previous (non-milled) tests

1)Willow charcoal airfloat pyro grade, bought on ebay from a famous seller

2)kno3 - agriculture grade 95% pure

3)sulfur agriculture grade (dusting) min 90% pure + inert components

 

 

I've just made another test:

build a mini paper tube - ID 15mm

putted inside 1g of granulated BP (grains big about 2mm) + 1 fake shell (a paper+metal tube) of 5g

when ignited (tube on the ground at 45°) the fake shell flight in *height* for about 2-2,5 meters

 

i think this are not good values!

 

i've used yellow dextrin to granulate BP. i have Shellac here, could this improve BP using instead of yellow dextrin?

 

thanks guys

[pyrosailor99]

OMG!

 

what bad discovery!

 

i recently ordered some chem from another supplier specialized in pyro supplies. just to give it a try i also ordered willow charcoal...

 

my last BP batch about i talk in this topic was instead made with the charcoal bought from the famous ebay seller...

(http://www.ebay.com/...=item3f0137da4d)

 

just some minute ago i've read about the importance of the charcoal in the BP making process. i already really knew that charcoal can turn a BP in a puke... and i really believe it because all my previous experiment failed trying many type of charcoal but all commercial for 'barbecue'... when i bought that charcoal on that ebay seller, i quickly tried to make BP and really jumped for happiness as i never obtained a so good BP (underline, *I* NEVER).. so moved from this happiness i've built the ball mill and made my first batch.

 

i'm really sorry for my holed head! from your replies i understood i haven't well explained myself.

with the text above (now in gray) i wanted just mean that i know how important is charcoal because in my VERY previous experiment (months ago) i used BBQ with bad result. when i bought willow on ebay i was happy because BP worked as i never seen before (but not as commercial BP). so i learned how important the charcoal. in my last 2 experiment (described in this topic) i both used willow charcoal, but from 2 different supplier. the first was the EBAY supplier (with this coal i made the 2kg batch). the second was a pyro specialized supplier

 

i have to say that in my mind i think my first experiment with the willow charcoal (taken from 1 of the 2 bags i got) was also better of my last milled experiment made with the OTHER BAG of the same willow charcoal (ebay seller)... but i think the quality is about the same.

 

just some minute ago, thinking on this, in my mind flyed the idea that the only one factor i could improve could be charcoal AGAIN... so i made a little batch of BP (40g) with Willow charcoal of the NEW SUPPLIER... i premilled chems in the coffee grinder 1 at time, then putted 4 balls in a square plastic container with chems and shaked it for about 5 minutes.

 

then i made a test to compare milled batch BP (call it BP1) and newest shaked BP (call it BP2) :

 

test mode: 3g of BP on a 10cm paper tape (not closed - open air) for each kind of BP with a piece of Visco to light.

 

first i want to say i noticed that BP1 was much dense than BP2... and i think this could be due to the fact that NEW willow charcoal could be lighter then the first in BP1... and this could add a point for the new charcoal.

 

when i lighted paper tape of BP1 it taken about 3 seconds to burn all.

when i lighted papertape of BP2 it taken about ONLY 1 SECOND to burn all !!

 

So, am i right in thinking new charcoal is BETTER then the first? or the fact BP2 was quicker could depend only by the fact that the BP wasn't milled (so there could be some micro air gab between molecules) ?

 

desperately trying to obtain good bp for lift charge. PLEASE HELP ME!

 

thanks all.

Edited September 9, 2011 by pyrosailor99

[pyrogeorge]

don't use bbq charcoal..the most of them are hard and maybe not very good cooked charcoal.

I make homemade C and the BP is perfect at the first hour of milling!

 

please post a video to view your BP.

[Peret]

I never had much success with BP until I started using willow charcoal, but what a difference when I did. Willow BP is a lot less dense than BP made with standard airfloat charcoal, yes. Now surprise yourself again by leaving out the binder and just granulating the powder through a coarse screen with a little water, then screen it when it's dry and test burn with the grains around 10-20 mesh.

[pyrosailor99]

thank you for suggestions.

i never used BBQ in this experiments. i know some time my head is not so good, so i edited my first post to make things clearer.

 

thanks all

 

PS. i will try to granulate without dextrin! but i think grains will break to easly when i will put the grains under a shell. if the grains break the lift become a powder and lose his power... do you agree on this?

[pyrosailor99]

Here are Video of my BP.

 

in this video you see in order this tests:

 

1) BP ballmilled granulated - big grains - charcoal used: Willow from ebay seller mentioned above

2) Same as 1) but smaller grains

3) BP hand-shaked in a plastic container for 1 minute with some ceramic ball inside. chems-premilled. Charcoal user: Willow from new specialized pyro supplier.

 

3 granulated BP test

 

here a zoom of the third paper test:

http://i51.tinypic.com/4hz7le.jpg

 

how do you rate all the BPs??

now you can reply to my previous questions having and idea of what i described by text...

 

PS. each paper contain exactly 2g of BP.

Edited September 9, 2011 by pyrosailor99

[pyrogeorge]

the last is better than the other batches..

i suggest you to mill less than 2kg..

Maybe 1kg is good start,i think that you overfill the jar..

[pyrosailor99]

thanks for the comment.

 

well if i have to follow the Lloyd guidelines (and i should as i should avoid wear of medias / warming of media while milling / dispersion of media powder into BP), i should mill 2,3kg of BP (for my jar).

 

The problem is that, yes, i know that in the video the last is the best of the 3 batches... BUT , the last is the batch i haven't milled at all! while the first 2 video are the same granulated milled BP (in the second i only reduced grains size)...

 

the last batch was made with always with willow charcoal but bought from another supplier...

 

could it be possible that the first 2 BP isn't good because i overmilled it?

[pyrogeorge]

i think that your jar hasn't got enough free space for proper rotation.

[Bonny]

 

could it be possible that the first 2 BP isn't good because i overmilled it?

 

I don't think you can overmill BP. The longer you mill, the finer and better mixed the ingredients become. When it starts to clump up (unless you have a wet ingredient) it (should) be done.

[Peret]

My BP granulated with just water is hard enough to be a nuisance when I need to crush some for meal. I find it hard to imagine any situation where the powder in a lift bag could be crushed to dust.

[pyrosailor99]

thanks, i will try. anyway the problem don't change when i have to make black match. i have to add dextrin or other binder there to make a decent BM.

 

Guys, my suspects go bigger on the ebay charcoal.

i've noted a big difference in the video i posted:

 

test 1 and 2 (same BP but different grain size) when burn make a lot of long-lasting SPARKS!

test3 burn all and with much less sparks and those few sparks are short lasting!

 

do you agree this could be imputable to the fact that my willow ebay charcoal could be not pure willow charcoal but a low quality mix with hardwood??

 

thanks!

[pyrogeorge]

Yes,maybe you bought bbq charcoal than willow

 

Edit:

Have you got any photo of your jar with media and composition?

I think that your jar hasn't got enough free space.

 

When i made my ball mill i had the same problems..And i say that theoretical is far away from reality

Edited September 10, 2011 by pyrogeorge

[pyrosailor99]

Edit:

Have you got any photo of your jar with media and composition?

I think that your jar hasn't got enough free space.

 

When i made my ball mill i had the same problems..And i say that theoretical is far away from reality

 

 

i haven't a pic of my jar loaded and the inside contant, but i post here a frame of a video of the ballmill...

http://i51.tinypic.com/2lkwd49.png

 

just to be clear on what you suppose:

actually my jar is 7liters empty. (protein container with several layers of US Tape gray)

as for Lloyd book, half is filled with 1'' ceramic balls. and 1/4 is filled with Composition.

as 1/4 is also exactly the gap between all Alumina HD Balls, the comp go just a few over the balls.

Actually when the mill is ON, i see ball crush and it works very well as actually BP (powder of test 1 and 2) is fine like talcum (maybe finer!)

I stored some gram of BP after 20minutes of mill, and after 3hrs of mill. the differene is evident. the powder milled for 3hrs tends easily to clumps and in impalpable. powder after 20min is rawest.

 

So i don't think the problem could be the mill grade of the powder, ALSO BECAUSE the test i've made with a different willow charcoal (another supplier) ( powder in the 3rd test of the video) that is more HOT and QUICK ) IS NOT MILLED AT ALL, i've just shaked comp in a plastic container for 1 minute. NO MILL AT ALL and it's BETTER than 3hrs milled powder!

 

The only other doubt i have is that Alumina HD balls could contaminate BP with alumina powder. i really don't think this too much because after many hard crash test in my hand there was no wear traces...

[Mumbles]

Whatever the actual variety of the ebay charcoal, the second charcoal you have is definitely much better and you should keep using that. The 2nd test is definitely passable, but the 3rd is so much better. Save the charcoal from the 1st and second tests for stars or something. It sounds like it would make good tails.

[pyrosailor99]

Save the charcoal from the 1st and second tests for stars or something. It sounds like it would make good tails.

 

yes this i what i think too.

 

do you also have suggestion on what to do of the 2,2kg batch of BP dust i made with first charcoal ?

my idea is to use it for priming stars but i think 2,2kg will be enough to prime stars for 2 years.... i think that BP is unusable for black match as for my use i need really fast BM and the only other tecnique to speedup BM in the passfire is to have multiple indipendend BM single strand in the same pipe... but i would prefer have 1 single quick strand... i'll experiment on this.

 

 

if you have suggestion on other uses... i'm here!

[Peret]

do you also have suggestion on what to do of the 2,2kg batch of BP dust i made with first charcoal ?

Rocket fuels, tiger tail or C8 stars, titanium comets, etc. Most will require you to add more charcoal.

[guntoteninfadel]

(Sorry for the mixing of the two measuring systems. Didn't have my calculator handy just now. )

 

Sailor it's been my experience that if you already have milled chemicals you need smaller media not larger. I realize your using a 7L jar and that could justify the 1" balls but that is theoretical. 1/2" or even 1/4" media gives much more surface area and I find it more efficient on the pre milled chems. I run an 8x12 inch jar with 1/4" media and process almost 2 kilos per batch in an hour to hour and a half ( I don't time it sorry, it just gets so loud I have to cut it off!). I personally like the larger media sizes for breaking up my charcoal.

 

Oh and the commercial grade is black and shiny because it is coated with graphite FYI

Edited September 16, 2011 by guntoteninfadel

[Arthur]

For most woods, the bigger the Kilo of charcoal the better the BP. A Kilo of hard charcoal is a big cup full and makes bad powder. Good willow charcoal occupies about three times the volume for a similar weight, and makes fine powder.

[guntoteninfadel]

That's the way I buy my BBQ charcoal.... If you see a fat bald guy shaking and comparing different bags, I'm trying to find the lightest one!

[Mumbles]

When I bought Cowboy brand charcoal, I picked out the light chunks for BP uses. They were possibly maple. I saved the heavy/dense pieces for cooking food. Both my BP and BBQ improved.

[pyrosailor99]

thanks guy for suggestions. i will try todo a batch with new charcoal.

 

for the Media i used... well, i know that smaller media do a finer job in less time... but the main fact is that this is only an optimization of the work time... i mean that probably with smaller media i obtain the same result of bigger media in much less time...

but here the problem is that i've already obtained a very fine powder and this is much slower than not-milled powder. so i'm convincing more and more that the problem is the charcoal.

i will update you when i will make another batch with the newer.

 

 

thank for all your suggestions.

[Arthur]

The British military powdermaker's tradition requires that the charcoal is made from debarked new growth willow the thickness of a man's finger. I once had some powder from big log willow charcoal and some from small branch willow charcoal and the small branch was much faster powder. Effort put into getting the charcoal right is always shown as improved product. Modern nitrate is far more pure than the old powder makers had available, and especially if you can get "refinery sulphur" (extracted from oil) the sulphur is more reliable, BUT we have lost the skills with charcoal and sometimes to go back to the best that our forbears learned is good.

 

Hard, or heavy feeling (dense) charcoal usually makes really bad powder, it may look black but it isn't good BP, and it never will be. Woods that make fluffy charcoal will usually make better BP -such as willow pine poplar and maple. I think there may be some value in the old concept that better BP comes from trees that grow best near water which may be why willow is well regarded. BUT experiment shows that cooked vine makes incredibly fast charcoal as does balsa, and Shinizu always likes Pawlonia charcoal. So while thin stick willow is good it's not the only good wood. BUT departing from the world's top ten charcoaling woods will leave you with failed attempts at BP.

 

Just one major warning, don't play with charcoaled straw -the product is a BP that is extremely sensitive, it may fire in normal handling. It's called cocoa powder from it's colour, it's very unforgiving.

Edited September 17, 2011 by Arthur