I have found that diamond tools are the best for the mixed fibre cloth i work with (Twaron and Kevlar/CF mixed) I use a diamond slit cutter for my dremel for the small parts, and diamond coated sanding blocks for sanding the edges.
I mostly make small parts with the Twaron or Kevlar mixed cloth on the inside, and get very nice clean edges... really no "fuzz" at all... diamonds are SHARP, and stay sharp...
Both my diamond sanding blocks (180 and 400 grit) have lasted several years now.. I wash them in Acetone regularly and once in while in soap and water.
I have a set of small diamond needle files that I use for the delicate work, inside corners, cut outs etc. they have also lasted for years, before i went into composites, I used them for glass-fibre printed circuit boards.
I have a set of tungsten drills also originally purchased for that purpose, they are still nice and sharp.

I'm not into high volume production, mostly one off "specials" and custom built parts, so I have probably not really reached the "wear limit" on a lot of my tools yet.

I use EC carbon / kevlar scissors for the mixed fibres, and ordinary scissors with a rough grind for CF and glass-

I normally never cut uncured wetted laminates.

"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

I was hoping for more input, ideas and solutions others have experienced while cutting, drilling, machining and edgeworking composite laminates, Kevlar in particular. Don't be shy, we are all here to learn! I would love to find an easier, faster way.

<<<While I may not be among the smartest men in the world, I am smart enough to learn from those who might be.>>>

Mark T.

I use a planer attachment on my dremel for straight edges. The blades get blunt super quick though. 

When I first saw the E.C.electric shears I thought they looked like some cheap piece of junk you would get like an electric screw driver from Canadian Tire or walmark. Soon to be thrown in the garbage. I did notice on most of the sites on youtube the most pros had them on their tables.
So I bought one with mixed hopes. This is I have found a tool that I absolutely could not be without. I cut everything but kevilar and chopped matte with it.
Vacuum bag  - flow media  - breather  -  carbon fiber  - glass cloth. All cut effortlessly. If you buy one and do a lot of cutting get an extra battery with your order.  

I have heard that waterjet cutting of kevlar works well and wet sanding the edges is the way to go. Its best to let the kevlar run short of the trim edge if in a layered stack. 

Fred

Thanks to Dravis and fgayford for your input.
I admit, because I am a cheap bastard, I have not used diamond tools on my laminates. Especially with Dremel type tools, I figured the high RPM would heat everything up too much, the biggest issue to overcome from my experiences. But Dravis has me thinking of finding a small portable, hand-held band saw with a diamond, flat or wire blade.
I wish I could have the pieces for my bear-resistant backpack waterjet cut! But the curved, irregular shape makes that proceedure impractical and it is my understanding Kevlar absorbs moisture. Lazer cutting might be an option for me but with the pieces not being flat it would also be quite involved. Fgayford, since you have an E.C. Cutter, treat yourself the next time you need to cut Kevlar. Consider purchasing a separate,Kevlar-only, blade though. While I use mine on just about everything because cutting is so effortless, it is truly impressive how it tackles Kevlar! I am certain it would handle fg mat as well, but I have no experience as I do not use mat.

THANK YOU TO ALL WHO RESPOND, YOU ARE HELPING ALOT OF US!!!
Mark T.

I always sandwich my Kevlar between layers of CF. I then use 400grit wet and dry to get rid of my feathering after using a cutting blade on an angle grinder to get through the laminate. I use the grinder sparingly to avoid heat build up. What I CAN add to this thread is that Kevlar has saved me a $20,000 motor! At 3:00 on the clip at http://youtu.be/8AqU7377fjU (other vids on the channel show the crash) you can see that the Kevlar and Carbon bash plate withstood 50m+ on ashphalt with the full corner weight of a Mustang sitting on top of it. USE KEVLAR and put up with the small problems. Where Kevlar is needed, nothing can replace it!

I would love to see more info on your bash plate. How did you work out the attachment points? How many layers of kevlar and what was the lay up schedule? Thanks for sharing!

The bash plate mounted on the cross members.  At the front cross member we welded on a plate that protruded 30mm rearward and simply put 3 bolts through it and through the plate.  At the rear cross member we welded on a plate that was a retainer with no bolts.  The rear of the bash plate simply slotted in.  So to remove the plate we simply undid the front bolts and dropped it out.

The design of the shape was simply done with cardboard, then a piece of scrap steel bent up and used as a mold.  This plate (that has been destroyed) was a wet layup so the mold did not need to be special in any way. The new bash plate will be vacuum infused and will be much stronger and lighter than this one, but I daresay the mold will be just as simple.

It had to withstand 3 forces that I could foresee.  It needed vertical strength in case the car simply dropped onto the road.  It needed strength along its length in case it caught crest/road and was 'pulled' rearward.  It also needed abrasion resistance in case it was dragged along the road (like what happened!).

So my material design used a lot of unidirectional carbon cloth placed along the length of the plate.  I interspersed this with twill for some some (much lesser) cross section strength.  At the bottom I used several layers of Kevlar, and a couple of layers of Kevlar/Carbon composite weave for looks (although I was hoping nobody would need to see it!).  One important factor was that if the plate caught the road surface and moved only 20mm it would have allowed contact with the sump, and likely caused a crack - and a crack in the sump is extremely bad!  So the design used a lot of Carbon to give it that incredibly stiffness.

The total composite would have been (it was a long time ago now) 5 layers of twill, 9 layers of unidirectional, 5 layers of Kevlar, 2 layers of Kevlar/Carbon composite.  All the scraps of cloth went into the stack as reinforcing (and there was a lot of scrap with the trapezoidal shape of the plate).  It ended up being ~15mm thick.

It was a wet lay up, so not as strong as it could have been due to difficulty fully saturating the fibers.  Also, it was heavier and thicker than it needed to be - which is why its replacement will be vacuum infused. BUT, it worked fine when it needed to perform. And it literally saved the motor and saved a LOT of damage to the underside of the car.

In the crash, the plate did grind through eventually, but only 'just' though.  It appears that the Kevlar did its job initially, and then progressively as the wear hole expanded.  It was like the 'leading edge' of the expanding hole was Kevlar, so it continued to do its job.  This is hard to describe in writing!

The bottom line is - when Kevlar is the material to use, nothing else can replace it.

I will post progress and results of the new one, but that will probably be months away.  I have to do hood, trunk, doors, dashboard, radiator panel, etc first!  Again!!

Targa Mustang, thank you for contributing. I certainly agree, whenever possible PUT THE KEVLAR IN THE MIDDLE OF THE LAMINATE. Unfortunately, my backpacks require the Kevlar on the outside because its lighter color reflects more sunlight and assists from cooking the contents and also its inherent abrasion resistance.
Mark T.

It appears the discussion on Kevlar laminate cutting and drilling and edgework has run its course. I was hoping someone would read my original post and explain how I was doing it all wrong and save me some time and aggravation. Thanks to those who took the time to respond. Your contributions are well received. Hopefully the procedures I incorporate and explained were of assistance to those blessed with the opportunity to deal with aramid laminates. HEY, ITS KEVLAR!
Mark T.