[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Kevlar spark gap armor - NOT!



Original poster: "davep by way of Terry Fritz <teslalist-at-qwest-dot-net>" <davep-at-quik-dot-com>

Any material must be applied in certain ways.

>I found a pair of common tin snips cuts it like butter.

>A bit more disturbing,

         Why?

>I found my big razor sharp grizzly bear hunting knife also cuts
>it like butter :-|
         Its a fabric.

         Fabrics can be cut.


>However, a Phillips screw driver and other blunt things are

>easily stopped dead by the fabric.

         Exactly.  They try to cut many threads/strands at once.
         This is hard.
         (how hard varies with the detail construction.)

>It is odd how much it resists the screwdriver, but the knife cuts right 
>through it.

         Quite expected.
         In WWI Silk was used for bulletproof fabric.
         Cuts nicely with a knife/scissors.

>I can easily see how many layers (like 1 inch)

         A lot less.  cf any bulletproof vest manufacturer.
         Also, they do specific development.

>of the stuff could stop a bullet. I am not so sure it would

>be great against knives

         Its not intended to be.
         For that plate, or chain mail...


>To the matter at hand. I worry that small heavy tungsten bits may go
>through a single layer.

         Not guaranteed.
         As the press has noted, certain sorts of bullets
         CAN BE designed to defeat vests..
         (And here is not the place...)
         A common bullet being softish lead 'cooperates'
         by deforming and becoming blunter.

>Certainly anything big, like a chunk of a rotor,
>>could easily be stopped buy the fabric.

         Most likely.

>But small sharp fragments, or say a tungsten rod tip hitting

>it at high speed, could go through it rather easily.

         Maybe.
         Depends on how small and sharp the bits are.

>It is thick, so I don't know how easily one could impregnate the
>fabric with epoxy.

         I fail to see what purpose this would serve.

>But in general, I can not recommend this stuff for spark gap
>armor.

         ANY material for ANY application needs to be designed for
         that application.  Using 'kevlar' is like walking
         in and getting 'capacitors' for a tesla coil.  Need
         to know, or test, to get the Right Ones.


>there are probably different types of Kevlar and all that, but this
>garden variety type soft ! fabric is not much use to us.
         Based on what testing?

         I believe kevlar (unspecified) is routinely used to
         'contain' fragments against possible failure, eg in
         gas turbine sets, etc.  Unless the gap has, or will
         generate 'razor sharp' fragments...


         best
         dwp

...the net of a million lies...
         Vernor Vinge
There are Many Web Sites which Say Many Things.
         -me