Re: Kevlar spark gap armor - NOT!

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "robert & june heidlebaugh by way of Terry Fritz <teslalist-at-qwest-dot-net>" <rheidlebaugh-at-desertgate-dot-com>

Terry: A class 3 flack vest will stop a 308 ARMOR PEARCING ROUND, BUT A 3
BLADE ARROW will slice through both front and back with little resistance.
( actual field tests) The differance is blunt force or slicing action.
   Robert  H
-- 


 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > Date: Thu, 06 Feb 2003 14:21:25 -0700
 > To: tesla-at-pupman-dot-com
 > Subject: Kevlar spark gap armor - NOT!
 > Resent-From: tesla-at-pupman-dot-com
 > Resent-Date: Thu, 6 Feb 2003 14:23:16 -0700
 >
 > Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>
 >
 >
 >
 > Hi All,
 >
 > My 4 x 5 foot sheet of Kevlar arrived today.  A very odd material
 > indeed.  It is sort of rough but not too bad.  Almost like a thick course
 > wool blanket.  I don't find it irritating to the skin, but some folks
 > might.  It is about 1/10 inch thick woven interlocked weave stuff.  The
 > fibers are long and well attached so it is not "dusty" at all.  Machining
 > and such would cause possibly bad dust, but just the fabric is pretty tame.
 >
 > http://hot-streamer-dot-com/temp/P2060019.jpg
 >
 > I found a pair of common tin snips cuts it like butter.  A bit more
 > disturbing, I found my big razor sharp grizzly bear hunting knife also cuts
 > it like butter :-|
 >
 > http://hot-streamer-dot-com/temp/P2060020.jpg
 >
 > However, a Phillips screw driver and other blunt things are easily stopped
 > dead by the fabric.  It is odd how much it resists the screwdriver, but the
 > knife cuts right through it.  A common 2 inch nail also has no problem
 > punching through it.
 >
 > I can easily see how many layers (like 1 inch) of the stuff could stop a
 > bullet.  I am not so sure it would be great against knives (but far better
 > than nothing...).
 >
 > To the matter at hand.  I worry that small heavy tungsten bits may go
 > through a single layer.  Certainly anything big, like a chunk of a rotor,
 > could easily be stopped buy the fabric.  But small sharp fragments, or say
 > a tungsten rod tip hitting it at high speed, could go through it rather
 > easily.  It is thick, so I don't know how easily one could impregnate the
 > fabric with epoxy.  Probably need very thin epoxy and a vacuum process to
 > do it right.  But in general, I can not recommend this stuff for spark gap
 > armor.  there are probably different types of Kevlar and all that, but this
 > garden variety type soft fabric is not much use to us.
 >
 > Cheers,
 >
 > Terry
 >
 >
 >