18 replies to this topic

[Shake]

Hi All;

I seem to be finding contradicting informtion from numerous sources on ball milling star compositions as to whether it is safe or not.

Is it based on particular comps that are more sensitive to shock?

In reviewing the some comps such as Tiger Tail and Willow stars I don't see much of an issue, but then ones like D1 Glitter with Al and KNO3 I wasn't sure.

Can anyone help clarify?

[Mortartube]

I certainly wouldn't ball mill anything other than straight gunpowder based mixes. Also I wouldn't recommend milling mixes containing metal powders as in many cases these are the more sensitive mixtures.

[pyromaniac303]

In reviewing the some comps such as Tiger Tail and Willow stars I don't see much of an issue, but then ones like D1 Glitter with Al and KNO3 I wasn't sure.

Can anyone help clarify?

Charcoal based star comps should have the blackpowder based ingredients pre milled, unless the particular mesh size of the charcoal is specified, then the other ingredients are screened in after milling. For instance with D1 I would ball mill the charcoal, sulfur, dextrin, potassium nitrate, and the sodium bicarbonate (however, do not mill this if you mill individual ingredients for colour stars in this jar, as it will cause sodium impurities unless your mill jar is cleaned very thoroughly). I would normally mill these for an hour for a 100g batch then screen in the aluminium. You should never put metal powders in your mill jar, and if you do so accidently it must be cleaned until your 100% sure no metal contamination remains, as it causes a spark hazard.

[Shake]

Thanks!

Just as I suspected...metal powders bad, charcol good!

[Skarphedin]

Hi All;

I seem to be finding contradicting informtion from numerous sources on ball milling star compositions as to whether it is safe or not.

Is it based on particular comps that are more sensitive to shock?

In reviewing the some comps such as Tiger Tail and Willow stars I don't see much of an issue, but then ones like D1 Glitter with Al and KNO3 I wasn't sure.

Can anyone help clarify?

From a safety perspective; never mill metal powders at all.

In my exeperience charcoal streamers like Tiger Tail and Willow requires extensive milling to perform good, and to avoid smoldering sparks falling all the way to the ground. (but others may have different experiences). Almost all other star compostions such as glitters is best screened. Make sure all your individual chemicals are quite fine and screen together. For D1 glitter I first mill charcoal alone and potassium nitrate alone. Then screen togheter will the other chemicals that are alredy fine.

[Bonny]

Many people ball mill INDIVIDUAL metals (especially MgAl), to get the size required. This process needs a dedicated milling jar NEVER to be used for comps. The only other thing I mill in that jar is kitty litter for nozzles.

[dr thrust]

hello, just testing the water so to speak, but im trying out the willow #2 formula of pyroguide were all the chems are screened together, pulveroned, then aloud to dry, and then ball milled for three hours to get the beautiful willow effect, this comp contains perc, lampblack, kno3, charcoal, im ready to mill, should i go for it? theres no sulfur to make the perc sensitive in the comp

[digger]

hello, just testing the water so to speak, but im trying out the willow #2 formula of pyroguide were all the chems are screened together, pulveroned, then aloud to dry, and then ball milled for three hours to get the beautiful willow effect, this comp contains perc, lampblack, kno3, charcoal, im ready to mill, should i go for it? theres no sulfur to make the perc sensitive in the comp

If you must mill it, I would only mill the kno3 and the charcoal together if for no other reason than I would not want to contaminate my my with perc. However I would never mill any composition with perc in it due to lack of knowledge and the fact I have never seen it recommended in any literature. There should be no need to mill in the lampblack due to its existing fine particle size (and you will never be able to clean it off your mill and media).

[Bonny]

hello, just testing the water so to speak, but im trying out the willow #2 formula of pyroguide were all the chems are screened together, pulveroned, then aloud to dry, and then ball milled for three hours to get the beautiful willow effect, this comp contains perc, lampblack, kno3, charcoal, im ready to mill, should i go for it? theres no sulfur to make the perc sensitive in the comp

The instructions on pyroguide do state to only ever mill KNO3,S and C...not perc. If you have already made the pulverone, I'd just re-wet and pump or cut the stars. Personally, I think perc is better saved for other comps such as colours or bright streamers, as for me it is very hard to get. Beautiful willow stars can easily be made without it.

I've never used lampblack, but if you do mill it, making another batch of normal BP would probably clean your jar and media.
Another great thing for cleaning jars and media is milling some kitty litter...

[digger]

I've never used lampblack, but if you do mill it, making another batch of normal BP would probably clean your jar and media.
Another great thing for cleaning jars and media is milling some kitty litter...

Interesting idea for the cleaning of the mill jar, I may give it a go sometime (I personaly have devoted jars for different chems/tasks as it is less hassle than cleaning them out).

Lampblack is the scourge of Satan. If you think airfloat charcoal can be messy, it is not even in the same league as lampblack. I have used it a couple of times, after weighing it out in a plastic tub it was impossible to clean the plastic even with vigorous scrubbing using a detergent.

Edited by digger, 25 July 2008 - 01:15 PM.

[dr thrust]

thanks for the imput, the instructions on pyroguide aren't really that clear, but they state that after the comp has been screened, wetted, dried, the comp is less sensitive and can be milled with caution, hmm lampblack a real pain but Ive been after a good willow formula for a while with most Ive seen using pot chlorate, which i dont fancy.

Ive tried bp based willow stars before there ok, but i suspect this formula will have nice bright but gentle orangery sparks , also i have dedicated jars and media for various comps ect with me just casting over 8 kg of lead media last sat afternoon! phew that was boring

Edited by chris m, 25 July 2008 - 07:40 PM.

[digger]

thanks for the imput, the instructions on pyroguide aren't really that clear, but they state that after the comp has been screened, wetted, dried, the comp is less sensitive and can be milled with caution, hmm lampblack a real pain but Ive been after a good willow formula for a while with most Ive seen using pot chlorate, which i dont fancy.

Ive tried bp based willow stars before there ok, but i suspect this formula will have nice bright but gentle orangery sparks , also i have dedicated jars and media for various comps ect with me just casting over 8 kg of lead media last sat afternoon! phew that was boring

I cheated, I just bought mine. 25Kg + 5Kg of ceramic media. I thought I would have enough for all purposes, but it looks like I might need another sack as some of my new chems are in granular form which were previously powdered.

I will be interested to see how the lampblack willow turns out, there was a formula banded about on the passfire forums not to long back that was supposed to be good. I would like a way to get rid of some lamp black (how can so little occupy so much space and be so messy).

[dr thrust]

righty them, ill make two batches one as described, and one like digger suggests just milling the kno3, charcoal together and see if there any real noticeable difference in performance hopefully there wont and i can go for the safer option.

yeah and everything own is now nice and black with the lampblack! its light stuff isn't it! i had to measure out 60g and it was quite a pile! and whist its out i thought id add 2% in a few rocket comps for a nice tail and with it being oily its helping to bind the fuel grains together so we'll see how that goes

Edited by chris m, 27 July 2008 - 12:21 AM.

[Mortartube]

I did an airshow many years ago where we blew lampblack into the air. I had to weigh it out into bags. It took the rest of the week to get it off. I definitely looked of tropical descent for a while.

[pyroduck7]

i only use my ball mill for bp. pestle and morter for everything else, - i might try makeing some german darkhead aluminum