Subject: Re: Identifying aluminum vs. magnesium

From: "John R. Johnson" <[email-masked]>
Date: Thu, 16 May 1996 13:53:44 -0500

On 16 May 1996, Craig Wall wrote:

<snip>
> 
> 
>    Another method is to cut a shaving with a sharp pocket 
>    knife; aluminum will give a curled shaving, and magnesium
>    will give a bunch of chips. (It's far less ductile.)
> 
>    What *I* need, if anyone can help, is a quick method for
>    I.D.ing the aluminum alloy one has.  I need to be able to
>    identify 2024 and 6061, or at least distinguish these from
>    architectural alloys. 
> 
I agree Craig, I don't know any reasonable way to do that easily.
Since the alloy is over 90% aluminum it weighs the same, has the same
stiffness, and looks the same.  Actually, I have found that many so
called "architectural" alloys are 6061.  It extrudes nicely!  That is
the determining factor for most of the architectural extrusions.
That is why I don't use any aluminum for structural purposes in my 
airplane unless it has the alloy type printed all over it! :-)
Of course, my cockpit fairings on the Pietenpol can be made out of just
about anything I can obtain!
John

---

From: [email-masked] (Craig Wall)
Date: 16 May 1996 18:02:38 GMT

In article <[email-masked]>, [email-masked] says...
>
>>David Baggaley <[email-masked]> asks
>
>>>Can anyone recommend a quick and dirty method of distinguishing these metals?
>>>I have an old circular saw that seems unusually light for it's size and I'm
>>>curious what it's made of.
>
>If you can touch it with an abrasive wheel, grinder, sander, 
>cutoff or whatever, aluminum should show no sparking while 
>magnesium should show a green spark. 
>
>Do NOT grind up a big pile of magnesium dust to try for a 
>big spark. Just a little touch will do.

   Craig Wall

.