823 replies to this topic

[Richard H]

It is possible to ball mill aluminium foil. However, you must take great care to reduce the pyrophoric hazard of the aluminium combusting when it combines with the oxygen in the air when the jar is opened. You want a controlled and slow oxidation process.

Coating the aluminium with around 0.5-1% stearic acid, and gradually exposing the powder to the air should help. Milling the aluminium in an inert atmosphere should also be considered if at all possible.

For more guidance read:
http://www.sigmaaldr...hbull_al164.pdf

[miniskinny]

And what possible results could come from ball-milling aluminum foil? and is there a decent yield of it? How long should I mill it? What would happen if it combusted in the unlikely event of my carelessness?

[Richard H]

I've never tried it so I cannot comment. A decent ball mill should produce a usable flake powder after a few days to a couple of weeks milling depending on desired mesh.

I'm sure you can guess what would happen if the aluminium did combust. There would be very little or no time at all to get out of the way.

[Phoenix]

In my mill (100mm ID, ~100 rpm, 1/2 full of flint pebbles and contain about 60g of Al) 2 days (48 hours) of milling reduced the aluminium to a fine powder, which since buying a set of screens, I have found to pass 200 mesh and mostly be retained on 400 mesh. The method of manufacture suggest it is flake shaped. Shorter milling times produces great flitter or firefly aluminium.

I made a more detailed post about this in the past, in one of the various topics on this subject. I don't really think that this is a very worthwhile method for making flash aluminium (since it takes too long and the results aren't great anyway), but is useful for making coarser grades.

Edited by Phoenix, 11 July 2004 - 05:26 PM.

[miniskinny]

Yeah the coarse-er types of aluminum are the kinds I am in need of

[paul]

I put coarse Al (Al from a lathe and cut into smaller pieces) into my ball mill. After 2-3 hours it looks like this

http://deutsch.250x.com/aluflitter.jpg [copy and paste]

Its everything from very fine to big flitters. After sieving it yo can use the flitter that are too coarse for other things like thermite reactions etc.

[Richard H]

I got an error; Access Denied. Don't think your host likes hot linking.

[Dan]

Richard H
It works on my computer.

sounds like a good idea, i better start saving my scraps.

[Jerronimo]

Copy and paste like he said.

[Richard H]

Ah sorry, I didn't read the post correctly

[neo]

How will this formula be?

30-40 barium nitrate
60-70 magnesium

Will it be a nice green flash?
Incase not, do anyone have a formula on a green flash?

[paul]

Bariumnitrate with magnesium is a very energetic mix. Is is very very fast and you?ll only see a strong but very short flash of green light. It flashes your eyes bad (If I can say that this way

But for green flash mixes refer to come.to/pfp or other pyro-databases.

[NUKE]

I wanted to find some Al to create some flash compositions but in my country i have to buy 1 kilo for 30 Euros so i would like to ask you if i can scratch a coca-cola can with an emery wheel in order to aquire some.Someone told me that these cans arent from Al and even if it was i would have Aluminium trioxide and not PURE Al.Is that real?

[Dan]

NUKE u can get aluminum powder from some fifiberglass suppliers or u can make it. the easiest was is to build a metal grinding machine. i havent tried it my self but i intend to build one.

[BigG]

Dan ? Aluminium bought from fibreglass suppliers will not get you any good flash powder. Aluminium for flash powder need to be much finer. You can make your own ? but best results are obtained from aluminium that is made for this purpose ? EG- one you get from pyro suppliers.