Newsgroups: sci.space.history,alt.folklore.urban,alt.astronomy,alt.paranet.ufo,
	sci.astro,alt.sci.seti,sci.skeptic,rec.arts.sf.written
From: henry@spsystems.net (Henry Spencer)
Subject: Re: Suicide in Space
Date: Thu, 2 Nov 2000 21:57:46 GMT

In article <m3vgu7ynlq.fsf@flash.localdomain>,
Mark Atwood  <mra@pobox.com> wrote:
>Okay, here's a similar question. The rails on a autoloader are
>typically lubricated with a very small drop of high quality machine
>oil (at least, my bottle says "with microscopic fluoropolymer additive
>for firearms, tools and machinery").
>How well do machine oils stand up to vacuum? Or would a "space rated"
>handgun need to be lubricated with graphite or teflon or somesuch?

Machine oil itself, not very well.  There are liquid lubricants for use in
vacuum, but they are specialty items.  The "fluoropolymer" (translation:
Teflon) content of that oil perhaps might keep things functional for a
little while, but the liquid itself would be gone pretty quickly.

Solid lubricants are definitely preferred for vacuum use.  Teflon is quite
popular.  Graphite is not a lubricant at all in vacuum -- in the absence
of air, it becomes an abrasive!  However, a similar but more obscure solid
lubricant, molybdenum disulfide, does work in vacuum.

(There are some weirder possibilities.  Thinking of firearms, metallic
lead actually makes quite a good lubricant in vacuum... but the lead oxide
which forms on its surface in air is an abrasive, so building, testing, and
handling lead-lubricated stuff is tricky.)
--
Microsoft shouldn't be broken up.       |  Henry Spencer   henry@spsystems.net
It should be shut down.  -- Phil Agre   |      (aka henry@zoo.toronto.edu)