# Diamond Wet Saw for Carbon Fiber and Kevlar



## mrsinbad (Apr 23, 2008)

Has anyone used a wet tile saw with a diamond blade to cut carbon fiber or kevlar? I'm eyeing something like this http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=91511 to keep the dust down and to make a smoother cut. Maybe the kevlar will fuzz up, but I'm not sure. 

Also, do the diamond blades come in different grits like medium, fine, extra fine?


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## precisionworks (Apr 26, 2008)

I've never cut Kevlar with a diamond blade, but have used a bandsaw, with blade teeth pointing up (not down) as recommended on the DuPont website:

_A conventional steel blade with 14 to 22 teeth per inch is fine for composites containing KEVLAR brand fiber. The teeth can be set in either raker or standard position. To get the best results, use a cutting speed between 3,000 and
6,000 FPM and a slow feed rate of about 1-2 FPM. In most cases it is best to mount the saw blade upside down so that the teeth are pointing up. This way the teeth will act as if they were knives and give a less aggressive, cleaner cut. With a standard shop mechanic's honing stone, hone a new blade before using it to remove any burrs left by the manufacturing process. Burrs catch the fibers and pull them, causing the fibers to fuzz. Backing will improve cutting quality. Masking tape can also serve as a backing. Water coolant is okay for heavy cuts.

Call 1-800-4 KEVLAR for additional advice.
_


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## LukeA (Apr 27, 2008)

precisionworks said:


> I've never cut Kevlar with a diamond blade, but have used a bandsaw, with blade teeth pointing up (not down) as recommended on the DuPont website:
> 
> _A conventional steel blade with 14 to 22 teeth per inch is fine for composites containing KEVLAR brand fiber. The teeth can be set in either raker or standard position. To get the best results, use a cutting speed between 3,000 and
> 6,000 FPM and a slow feed rate of about 1-2 FPM. In most cases it is best to mount the saw blade upside down so that the teeth are pointing up. This way the teeth will act as if they were knives and give a less aggressive, cleaner cut. With a standard shop mechanic's honing stone, hone a new blade before using it to remove any burrs left by the manufacturing process. Burrs catch the fibers and pull them, causing the fibers to fuzz. Backing will improve cutting quality. Masking tape can also serve as a backing. Water coolant is okay for heavy cuts.
> ...



Then would a knife blade for the bandsaw work also?

I've only ever cut pultruded carbon fiber forms, but they were nothing for a bandsaw.


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## McGizmo (Apr 27, 2008)

I have cut carbon fiber and shaped and ground it using diamond and water with excellent results. The water keeps the epoxy from heating up and getting soft as well as loading up in your cutting tool. _Cool_ CF is brittle and easy to work with, IMHO, provided you use sharp and hard abrasives and cutting tools.

Kevlar is another kettle of stinky fish though. It is hydrophilic and it does like to fuzz!!! Those are some interesting tips shared on cutting kevlar. I have a couple surf skis that are laid up with a hybrid carbon/kevlar cloth and the damn kevlar causes all the trouble.

I think water is a great idea with any FRP and composite laminates and earns consideration on the dust issue alone.


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## precisionworks (Apr 27, 2008)

> water is a great idea with any FRP and composite laminates


If there are many parts to do, paying a shop with a waterjet would be ideal. Zero heat input, high definition cuts, no dust to worry about. I cut just enough G10 to really dislike it, but not enough for waterjet.


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