24 replies to this topic

[PyroNitrate]

Get a food blender, you dont even need a mill attatchment. Also have a jug of water standing by.

Now, put enough soluble material (I use NaCl) into the blender and turn it on. You want enough so the blender doesnt throw everything around, but instead sets up a kind of cycle where the stuff comes up from the bottom and gets replaced by the stuff on top, so it plunges down the middle of the blender like a sinkhole.

Now, get some aluminium foil, and rip it into smallish pieces, about 1-2" square roughly. Place these into the blender, and manually shake it a bit to mix the foil in with the NaCl or whatever. Now, turn on the blender and use it in short bursts so as not to overheat it.

The foil gets finely ground up and has no escape from the blades as there is salt all around it!

Now, add the ground up mixture to water, the salt dissolves, and now filter the Al powder and there you go.

Source: Sonny Jim

[Matt]

Or you could make a grinding machine......

[Stuart]

How would you do that

Stuart

[PanMaster]

no such thing as simple aluminium powder, just read all the rec.pyrotechnics threads on it for a few hours and you'll learn you're wasting your time. electroylsis is the only promising method, but you need nitric acid or magnesium
what seems to be a dust is only 150 mesh, ball milling aluminium filler 300 mesh or using aluminium spray sounds good

[Richard H]

This method seems rather ineffective to me.

[BigG]

no such thing as simple aluminium powder, just read all the rec.pyrotechnics threads on it for a few hours and you'll learn you're wasting your time. electroylsis is the only promising method, but you need nitric acid or magnesium
what seems to be a dust is only 150 mesh, ball milling aluminium filler 300 mesh or using aluminium spray sounds good

I disagree. I have seen a home made grinding machine and it produced about a pound every 24 hours - with a variety of flakes, many pass 400#

[Stuart]

How did you build it or do you know where I could get the plans?

Stuart

[PyroNitrate]

This was posted on another forum by the source i listed, i have no further information. I can tell you i have tested this with ok results. Try ball milling it for atleast an hour after it is done blending. I got a good mesh for rain effects.

[BigG]

How did you build it or do you know where I could get the plans?

Stuart

I did not build one myself. Two left hands I also know that someone posted pictures on some site ? but this site is down for quite a while.

The basic idea is to have a rotating axial (using a 1/2hp motor or above) covered with a sand paper (one of those oxide sand papers ? like piranha 80). Under the axial, is a large bowl of water, where the axial bottom half rotates through, while above the axial is sort of a press. The aluminium block is attached to the press using a vice and is pressed down onto the sand paper. The ?press? can also be a simple arm that has a building block attached to it to is will lay heavy on the axial. When you start the motor, the sand paper sands the aluminium block and the powder is washed into the bowl of water when the axial rotate through it.

I hope this is a clear description ? I can try to post a drawing or something.

[Stuart]

Thanks. I did find a site that gave a very similar description and was going to ask about it because of the other content on there was of a HE nature and some info on pyro was inaccurate e.g. ball milling BP for 24 hours to get something good.


Stuart

[Stuart]

Have uploaded a picture based on the description you gave me and the one on the other site to Here. If it doesnt work, type http://www.geocities...urpyrotechnics/ and then add "grinder.JPG"onto the end

Is this what it looks like and how fast does the motor spin?


Stuart

Edited by Stuart, 14 November 2003 - 05:10 PM.

[Pyromaster2003]

i have also seen that site with the Al grinder. it also mensions the Al reacting with the water and producing flammable Hydrogen gas. forgot how to over come this problem though.

[BigG]

Have uploaded a picture based on the description you gave me and the one on the other site to Here. If it doesnt work, type http://www.geocities...urpyrotechnics/ and then add "grinder.JPG"onto the end

Is this what it looks like and how fast does the motor spin?


Stuart

Well, yes, the picture is not bad ? although the one I seen used a sort of an ?arm? instead of a press, and then vice a brick on the arm (to put weight on the arm) and an aluminium tube under it. The rotation speed was not extreme. I don?t think he had more then 500-600 rpm going, but it was long time ago?

As for hydrogen gas ? well, you should not have a problem with hydrogen gas ? unless your water contains nitrates ? and I don?t see why you would add nitrates to your water. If you want to be on the safe side ? add 1% boric acid and this will naturalize this reaction.

BTW Stuart ? this ?ball 24 hours to get something good? is not totally wrong. Lloyds already showed that it is hard to get commercial quality BP unless you ball mill for at least 24 hours?

[tajmiester]

Correct me if I'm wrong but:

2Al + 2H2O -------> 2AlOH + H2

Hence Hydrogen.

Tris

[Stuart]

Yeah but it would take a long time wouldnt it?

Stuart