Kevlar spark gap armor - NOT!

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

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