Reply-To: "Douglas W. Johnson MD" <LANCAIR1@prodigy.net>
From: "Douglas W. Johnson MD" <Lancair1@prodigy.net>
To: <lancair.list@olsusa.com>
Subject: U-238 counterweights
Date: Sun, 20 Dec 1998 17:54:54 -0500
Message-ID: <01be2c6b$c21484c0$69999cd1@douglas>
Mime-Version: 1.0

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Dan recently commented on using depleted uranium as counterweights.  Indeed
weight savings can be realized if you use something with a specific gravity
above that of lead (about 10, as I recall).  Both tungsten and depleted
U-238 have a specific gravity of about 19, and thus would be useful.
Tungsten is very hard to drill out, however, and you must be careful not to
overbalance TOO much (DL Simmons and I speak from experience) with it.
Similarly, U-238 should not be drilled, as it can can have some ugly
properties if heated.  I have used three 1# slugs of U-238 in my rudder,
embedded in a Tungsten block, and think I perhaps saved 5#.  Up to you
whether or not you think the effort is worth it.  Doug Johnson (I deal with
radioactivity every day, and just couldn't pass up the chance to use some of
this material).