Subject: Re: <None>

From: [email-masked] (John Kopf, X6305)
Date: 1 Dec 1993 20:17:52 GMT

In article [email-masked], [email-masked] () writes:
> HELP me make powdered alum
> 
> please help me to learn how to make powdered aluminum for my 
> model rockets 
> 

The *cheapest* way is to FILE a block of aluminum and catch the filings on a
sheet of mewspaper!

JK

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From: [email-masked] (Mark Forbes)
Date: 2 Dec 1993 06:55:04 GMT

[Looking for info on 'making aluminum powder for model rockets]

We'll all be happy to help, as long as your next-of-kin sends out the
videotape of your final moments. :-)

Why don't you just buy some? VWR Scientific and suchlike chemical supply
houses routinely stock such stuff in a variety of grades. Call your
local university ( I think you're *at* one) chemistry department and
ask them. They may even be able to sell it to you. 

If you're going for pyromania, why not use magnesium? It's easy enough
to get, and machines easily. Call a local machine shop and see if anybody
around there has machine work done on magnesium. Most shops would be
happy to get rid of the chips. They're a fire hazard. You can make
magnesium powder with a grinding burr and a glob of magnesium. The
bigger the glob and burr, the more powder you'll have the sooner. 

Mark G. Forbes | [email-masked]
Corvallis, OR  | 503 754 3104 home phone    | Hardware R & D
"Never ascribe to malice that which can be blamed on the engineer."

Don't even *think* about trying any of this at home!

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From: [email-masked] (John Bottoms)
Date: Thu, 2 Dec 1993 15:03:54 GMT

Please do not attempt to make powdered aluminum in your home. Powdered
aluminum is highly explosive, exploding without even a containment wrapper.
It has about 3 times the specific impulse of dynamite. If you are interested
in safe techniques for handling manufacturED materials, contact the people
at rec.pyrotechnics. Powdered aluminum is blued to prevent it from oxidizing
and is referred to as german silver or flash powder. Graunulated aluminum
is much safer but still NOT something you want to use in a model rocket.

 -johnbottoms
  Concord, MA

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From: [email-masked] (bill nelson)
Date: Sat, 4 Dec 1993 07:27:45 GMT

[email-masked] (John Bottoms) writes:
: Please do not attempt to make powdered aluminum in your home. Powdered
: aluminum is highly explosive, exploding without even a containment wrapper.
: It has about 3 times the specific impulse of dynamite. If you are interested
: in safe techniques for handling manufacturED materials, contact the people
: at rec.pyrotechnics. Powdered aluminum is blued to prevent it from oxidizing
: and is referred to as german silver or flash powder. Graunulated aluminum
: is much safer but still NOT something you want to use in a model rocket.

Bullshit - to put it politely. You have absolutely no idea what you are
talking about.

It is easy to grind your own aluminum - and safe.  The problem is that it
oxidizes rather badly if you use a grinder. It can be done with a file, but
is very slow.

There is no way that homemade powder is going to be hazardous - you cannot
make it fine enough.  As long as it is not mixed with an oxidizer, you would
be lucky to get it to burn.

Powdered aluminum is not "blued". There are two basic types of aluminum -
atomized and milled. The atomized is somewhat spherical, the milled is 
fairly flat, and is often called "flake". Both forms form aluminum oxide
on the surface, which prevents further oxidation. This happens to all
aluminum as soon as it is exposed to oxygen or water. 

German silver is an alloy of copper, zinc and nickel - it is also called
nickel silver.  Flash powder is a mixture of powdered aluminum and an
oxidizer - usually potassium perchlorate - although other oxidizers also
work quite well.

The "dark" aluminums are that way due to their method of manufacture. The
aluminum is placed between sheets of paper, then milled. After milling, the
paper is charred - and not removed. This gives it the characteristic almost
black color.

Note that the US government, which tends to be overreactive about chemicals,
rate powdered aluminum as a flammable solid, not as an explosive.

Yes, I am a pyrotechnician. I also post frequently to rec.pyrotechnics.

Bill

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From: [email-masked] (David Thompson)
Date: 4 Dec 1993 12:52 PST

I recall reading somewhere (I think that it was in Scientific 
American, though I do not recall when other than some years ago in the 
"Amateur Scientist" section) about a homemade rocket powered by powdered
zinc and sulphur.

Cheers,
Dave Thompson      [email-masked]

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From: [email-masked]
Date: Sat, 4 Dec 1993 23:04:46 GMT

> Dave Thompson      [email-masked]

I have a friend who used to build rockets this way.  He made one that
went over five miles up and had the Air Force came ask him some questions
cause it came down near the Hanford nuclear reactor.  He machined the
nozzles from a block of graphite...Sounds like good fun!
This was a number of years ago.

Brandon France

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From: [email-masked] (Michael J. Edelman)
Date: 6 Dec 1993 13:21:21 GMT

>"Amateur Scientist" section) about a homemade rocket powered by powdered
Yes, it was in the Amateur Scientist column, and was reprinted in the 
book of the same name published by SciAm- a copy of which I treasure.

A friend and I made a a ZnS rocket in the 6th grade, and amazingly enough
lived to talk about it- probably as we used a non-metallic casing!

--mike