Subject: Re: "spent" uranium: can I get some?

From: [email-masked] (James Kirkpatrick)
Date: 20 Feb 95 00:05:02 MST

Speaking of Tungsten (just to help drift the thread :-)

I have heard of tungsten being used for the pendulum weight (the "bob"
as it is called) on precision clocks, due not only to its high density
but it apparently has good thermal characteristics (low coefficient of
expansion).

But where do you get, say, a 3-inch diameter bar 6 inches long?
Any idea of the cost?  Machinability?

Jim

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From: [email-masked]
Date: 20 Feb 1995 04:26:39 GMT

In article <[email-masked]>, [email-masked] (Mark Kinsler ) writes:
>
> 
>I have heard that "spent" uranium is used for bullets in 
>aircraft-mounted machine guns and for flap counterweights on some 
>airplanes.  It is used because its density is something like twice or 
>three times that of lead.  This is fascinating, and I've been wondering 
>about the stuff.  Is it radioactive?  Is it legal to own?  What does a 
>chunk of it feel like when you pick it up?  Where could you buy some?  
>What does it look like?  
>                                Mark Kinsler
>
               
Says here in my calculator that the density of lead is 11.4 grams/cm**3; 
the density of uranium is 18.9 grams/cm**3. So the ratio is a measly
1.658, not 2 or 3.

I've heard that uranium compounds tend to be fairly toxichemically,
apart from any dangers from radioactivity. I worked on an xray machine
in which we used depleted uranium to absorb xrays; the depleted uranium
was nickel-plated because (I'm told) otherwise it builds up a dusty layer
of unhealthy oxide. I believe some kind of okay from the Nuclear
Regulatory Commission was needed to use the stuff. Even though it was
largely depleted of the radioactive isotope, it still had enough of
it left so you could easily locate it with a Geiger counter.

The density of gold is 19.3 grams/cm**3 and the density of tungsten is
about the same. So if you're interested in heavy metals, I think you'd
be better off buying yourself a few pounds of gold to play with, or
perhaps a few pounds of tungsten if you don't need the softness or
malleability of gold. Or you could get yourself some platinum (density
21.4 gm/cm**3) or iridium (22.5 gm/cm**3)...
                      ...when I sit down to write
Don Holly             my intentions are always blameless however deplorable
                      the ultimate effect of the act may turn out to be.
                                           --Joseph Conrad

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From: [email-masked] (Mark Kinsler )
Date: Mon, 20 Feb 1995 02:28:56 GMT

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From: [email-masked] (Russ Kepler)
Date: Sun, 26 Feb 1995 22:01:04 GMT

In article <[email-masked]>,
Tom Clarke <[email-masked]> wrote:
>[email-masked] writes:
>
>I think it burns too, like magnesium.

It's mot all that toxic, and it's no where near as flammable as Mg.  I
asked a neighbor who happens to be the director of the Inhalation
Toxicology Research Center just how toxic metallic U is and he said
that it's about the same as lead overall.  You get a light coating of
an oxide that's not terribly biologically active and which isn't all
that bad.  BTW - the ITRC is *the* government center for this sort of
work, so he's a good source for this info.

-- 
Russ Kepler posting from home  [email-masked]

                      Please don't feed the Engineers

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From: [email-masked] (Linda Patrick)
Date: Thu, 02 Mar 1995 10:15:31 -0800

In article <[email-masked]>, [email-masked] (Doug
White) wrote:

> OK, I know this isn't rec.crafts.plasticworking, but you can't win 'em 
> all.  I have been making something out of white PVC.  Mostly from pipe 
> and fittings, but some heavy sheet stock as well.  In order to make it 
> look a bit better, I filed off the molding marks and raised lettering 
> from the fittings, and then tried sanding it with 600 grit emery paper 
> (the black stuff) before buffing it.  The only problem I've had is that 
> the plastic is soft enough that some of the emery that wears off the 
> paper gets embedded in the plastic, and leaves a blackish smudge.  I can 
> buff it out, but the plastic is soft enough that you have to be careful 
> not to overheat it.  I'm also concerned about contaminating my buffing 
> wheel with 600 grit emery, which will make polishing acrylic to a clear 
> surface impossible.  I've never had this problem with harder plastics 
> like acrylic.  They sand just fine, and the grit either stays on the 
> paper, or doesn't get stuck in the plastic.  I've thought about using a 
> paper like aluminum oxide,which has a whitish-clear grit.  This wouldn't 
> show as much in the plastic, but it could still gunk up my buffing 
> wheel.  It's also hard to find in a really fine grit.
> 
> This project is hardly crucial, and I can live with a moderately crude 
> finish, but I'm curious about the Net's wisdom on the subject.
> 
> Thanks!
> 
> Doug White

HI Doug,

Try getting wet or dry 600 grit sandpaper instead of 600 grit emery paper
or try using the 600 grit emery paper wet. You can also get silicon
carbide abrasives (in powdered form) from a rock or lapidary shop and just
make up a paste (mix with water) and using felt cones or small felt wheels
that fit on a flexible shaft or dremel tool to work the abrasive 600 grit.
You can also get aluminum oxide in powdered form at the same lapidary
shops.

Hope this helps.

Regards,
Linda Patrick