Aluminium

[jaysgoh]

I'm here again. I bought two pounds of lab grade aluminium.

I'm here not to mess with flash powder. I just wanted to try it out what type of aluminium is it.

Can you identify for me?

 

It was powder form in the jar.

I mix kclo3 and aluminium by 7:3. Diaper method, full protection with anti static cloth.

After 20 min. It does not ignite! I don't know why. Fp should be sensitive to heat. I use glowing wooden splinter and torch. It did not ignite tho.

I measure 1g of aluminium and tiny small tea spoon of charcoal powder and mix them. I mix them again with my kclo3.

It fairly burn with white colour. Most likely like kno3 + sugar. My kclo3 is lab grade too, I grind it finely and almost airfloat.

Do you think my al is atomised or flake? If it really atomised, what can I do? Means future I can't get a good flash powder when I am professional enough to do that? I couldn't get any al powder here.

I mix my kclo3 with sodium benzoate. It does not burn, it pop after 1.5 sec heat.

 

*I do this just to identify type of aluminium

* all composition make with care

* all composition not more than 10mg

. Safely discarded all live composition.

Edited March 24, 2014 by gohjiejing

[Seymour]

Lab grade aluminium is not usually flash powder grade, I would say it is atomised.

 

Try it in some glitter mixes, they should work better

 

I definitely suggest you use a fuse to test fast burning compositions, especially flash powder. I don't know how long your torch or splint are, but I would definitely want to be at least a few meters back from even just a gram of ordinary flash going off unconfined.

 

I was once unlucky enough to be about 30cm (a foot) from much less than a gram going off on a burning piece of paper. I assume that as a result of the paper contorting as it burned, the flame/explosion was very focussed and I got a small serious burn, but centimeters away my skin was only mildly burned. Strange and unpredictable pyro can be.

[jaysgoh]

Thanks Seymour,

My wooden splinter length about 25cm and 0.6mm thick.

In that case, I saw previous post but I still don't understand in term of pyro word.

Mumbles said it will be better if for big salutes. (from dark aluminium)

Maybe I'm wrong.

So that means lab grade aluminium useless for flash? No hope for flash it was so hard to look for aluminium powder. But it was not suitable, sigh

Thanks

[nater]

IF it is atomized aluminum, it can be used for larger salutes. It needs to be well confined and have a good flame to initiate it. Some also use a flash bag with flash made from dark aluminum to help it out.

 

Atomized aluminum also makes good glitter or a good addition to charcoal effects. It is certainly nice to have some available, especially since you say you are not here for flash. You might just have found exactly what you need.

 

It would be nice to know what you have. Do you know anyone with a microscope who can analyize a sample for you? Can you post pictures?

[leedrill]

ill agree with all posts here but to say if you had even a gram that you had tested and you had a 25cm stick that you lit it with thank god it wasn't dark al

 

or you very well could have gotten seriously hurt by the end of the stick getting blown off and being a projectile let alone burns

 

im sorry to seem like a dick but you really need to be more cautious you should have a lot more respect for the potential energy in the compositions we use

i seem to remember you lighting bp with a lighter directly heed the warnings from that post or when you get dark al and a ball mill you will learn the hard way what not to do treat everything in this hobby like its going to hurt you because it has so much potential with out safety measures

[jaysgoh]

It is atomised. I search for Google. It's not flake.

Guy I would like to know what is dark al? Charcoal + al flake =600mesh al powder?

[Zumber]

It is atomised. I search for Google. It's not flake.

Guy I would like to know what is dark al? Charcoal + al flake =600mesh al powder?

what charcoal has to do with aluminium powder??

[FlaMtnBkr]

Probably because he found something saying how German dark was made with foil backed paper which is charred and the paper turns to charcoal.

 

In that case there is/was some charcoal in with the aluminum.

[jaysgoh]

No idea, what I know are they mix charcoal and aluminium powder together. Maybe I'm wrong.

[Mumbles]

Yes, you are wrong about how dark Al is made. Please see FlaMtnBkr's post for an idea of how it's really done.

 

For the sake of humanity, and our hobby, please never mess with flash powder. Given all of your posts, you've made it pretty clear you are more than capable of hurting yourself with far more tame compositions. Seriously, do some major reading and get some common sense.

[ollie1016]

Hello all,

 

I'm just thinking, I'm not suggesting that gohjiejing goes and tries this but...

 

Is it possible to ball mill the atomised Al to turn it into flake?

 

I ball mill Al powder in one of my rubber mill jars with stainless steel balls (cost me a fortune).

 

Just putting the idea/ proposal out there.

 

I know everyone will tell you not to mess around with flash powder. But seriously, just don't. A 0.25g of 7:3 perc : 325 bright flake Al firecracker is terrifyingly powerful, and loud. It deserves a lot of respect. Anyway flash rant over

 

Ollie

[taiwanluthiers]

Not sure but I'd avoid ball milling metal if I could... I read about plenty of accidents involving ball milling metal such as spontaneous ignition or the metal igniting after milling (due to oxygen exposure)

[pyroChile]

Hello all,

 

I'm just thinking, I'm not suggesting that gohjiejing goes and tries this but...

 

Is it possible to ball mill the atomised Al to turn it into flake?

 

I ball mill Al powder in one of my rubber mill jars with stainless steel balls (cost me a fortune).

 

Just putting the idea/ proposal out there.

 

I know everyone will tell you not to mess around with flash powder. But seriously, just don't. A 0.25g of 7:3 perc : 325 bright flake Al firecracker is terrifyingly powerful, and loud. It deserves a lot of respect. Anyway flash rant over

 

Ollie

 

 

I think so. Grind with 200% w/w mineral alcohol and add 5% w/w oleic acid. Grind more to 30 hours. Balls of 1/2" (steel)

 

 

 

 

Best,

 

 

 

=)

[Peret]

This is what dark aluminum looks like, and burns like. Note that both samples light with an ordinary butane lighter, and both crack the tile they're sitting on. The second sample (the good one) starts at 3 minutes.

 

http://www.youtube.com/watch?v=r_kVM7TmZe0

Edited May 2, 2014 by Peret

[MrB]

Probably because he found something saying how German dark was made with foil backed paper which is charred and the paper turns to charcoal.

 

In that case there is/was some charcoal in with the aluminum.

A quick google search returns the "known" way to make "home made German Dark" as being tin foil, and wood charcoal, so i'd say it's a common misconception. I actually have no idea how it's made, Your description is quite in line with Star Molecule's description, where they also claim to have one of the original machines, so i guess it's true. (i'm not questioning, as i said, i have no idea, and the method seams reasonable enough.)

 

Now... Given the info we got, wouldn't powder tin-foil with charcoal made from paper, milled in a ball mill (closest thing we got to a hammer mill) be a pretty good reproduction?

We don't really know the ratio of paper to foil, so making an estimate as to hom much charcoal that should be added is pretty much impossible. I would lean towards "less is more" and add only enough to get the expected result...

 

Yes, you are wrong about how dark Al is made. Please see FlaMtnBkr's post for an idea of how it's really done.

There is so much "this is how to do it" on the net, so no wonder he's confused. Hell, all the "fact" sites that touch the topic copies the words of some 14 year old that states you should use a table spoon of charcoal to a unspecified amount of aluminum.

 

I don't even use alu for flash anymore. For better or worse, i use MgAl, that i make my self. I gave up on Alu ages ago. Just comparing cost means going the MgAl route was a bright idea, it also gives a consistent result, the only problem i have these days is getting the magnesium... Even as scrap magnesium gearboxes are quite expensive. Luckily it's getting more and more common to use magnesium alloys with a magnesium-content of 90-95%.

 

I cant help wondering. Does the source for the charcoal really make that much of a difference? I'm sort of thinking it has more to do with the amount, then it being from paper. Also, since they say kiln, and burned of... less charcoal, more lamp black?

 

Oh well. It's 3 in the morning, and i'm still here. Thats when you should have gone to bed hours ago instead of asking stupid questions, and thinking out loud...

Hey, at least i know, right?

B!

[Mumbles]

I'll see what I can do about gathering up legitimate knowledge and statements on this.

 

I'd hardly take anything I found on youtube, indestructibles, a majority of internet forums as truth though. Dumping in carbon and stearic acid milling is going to be different than a more involved processing method. I do science for a living, but even still, I prefer to have multiple points of confirmation from legitimate sources.

 

One of the original methods of making this type of material is documented. Aluminum is coated onto paper to allow for it to be rolled or milled much thinner than possible otherwise Without the paper, milling would result in the aluminum be impact fused back together. The paper is then charred off and mostly removed, though some will remain. The details on these things are not explicit, and it's not entirely clear if it's still done this way. I've read it originated from processing a surplus of thin aluminum coated paper common in sealing cigarette packs and used as gum wrappers. This occurred originally in the 1950's initially in Germany, and was transferred to India for the initial establishment of that product.

 

The assays I've seen for some dark Aluminums are greater than 92% Al, and less than 2% Al2O3, Carbon, and Fatty Acids. An assay from a manufacturer of a product sold as Indian blackhead (Mepco black 000) lists the aluminum content as greater than 96% and the fatty acid as either .5% or between .5% and 1% depending on what assay you look at. To me, it would make sense to have a fairly consistent fatty acid and carbon content, and a slightly more variable Aluminum to Aluminum oxide content. I've read all sort of different things about milling in vacuum, or the various gasses used as an inert atmosphere or mixture.

 

Something that might help would be an analysis of fatty acid content. The amount of fatty acid content required for the finest particle size by ballmilling alone would seem to contradict my previous statements of analysis. You generally see somewhere around 5% required to get into the single digit micron range. Perhaps more is used in processing, but it seems most is removed for the final product.

 

The carbon content and true state cannot be ignored either. I've heard more than one person state that aluminum carbides formed either during charring or during mechanical milling adds to the reactivity of these very fine aluminum flakes.

[MrB]

Wow. Me being tired really is a good thing.

 

Yes, anything on the net pretty much cant be trusted at face value. But even some wikipedia, and ask.com claims dark alu's are made by adding charcoal, so someone trying to verify it, might end up with... uh, a false positive, so to speak.

 

If you can find the info, and feel like taking the time, i'm sure it would be a interesting read for a lot of people.

All i got, so to speak, is the link i posted above, and it doesn't really contain any info, just outlaying the general concept.

B!