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Just how do you sharpen "plastic" knives?

Discussion in 'Knives' started by AmbuBadger, Mar 11, 2008.

    AmbuBadger Loaded Pockets

    Don't worry, I'm not looking to take something into a courthouse or anything, but I've seen a lot of "letter openers" and "tent stakes" out there made of Zytel or some other fiberglass, and they say you can sharpen it. I ran a search, found nothing... so anyone ever pull this off, and if so, how sharp could you get? I'm guessing the edge doesn't hold for long though...
    • +1 Supporter

    KeyGrip Loaded Pockets

    Very carefully? How sharp are these objects to begin with?

    clutchUSMC Empty Pockets

    use fine grit sandpaper and you can put a new edge on it,but you will only get 1 or 2 uses before you have to do it again.
    • Moderator

    Lugsalot Uber Prepared

    I've heard that a fine emery board will do the job. So will very fine sandpaper, as clutchUSMC suggests.

    Plastic cutting implements are intriguing to say the least, but certainly impractical for anything but tearing open envelopes and the like.

    carrot Loaded Pockets

    Plastic knives like Cold Steel's Nightshade FGX series seem to me like last ditch weapons. Do as they suggest and leave 'em in your shower basket, in potted plants, hidden around the house, and if you ever have to use them (hopefully not!) just throw 'em away and get new ones. Sandpaper could work, however if there's anything more frowned upon than a "scary looking" folder or an "even scarier" fixed blade it's a plastic knife because they can circumvent metal detectors (but not X-ray scanners, as they are fairly dense).

    HoopleHead Banned

    i have a few of the cold steel nightshade stuff, which outside of pure carbon fiber or G10 knives are probably some of the better plastic knives. they still dont cut very well at all, and are really more for stabbing than anything. so better to have a nice sharp thick point and thick "knife" than trying to get an edge on it IMHO

    callmekipling Empty Pockets

    For Zytel or other fiberglasses, use sandpaper. Staple it to a piece of wood and use it like a stone, if you don't have a belt grinder.

    For plastic, you can use sandpaper, but you could also just use another knife.

    Glass > metal > plastic.


    (and then there was that time I used an AccuSharp and a soldering iron to carve up a cutting board I found in the trash :-X)

    Codeman Loaded Pockets

    Also, you may want to wear a mask when sharpening. Depending on what the knife is made of, you do not want to breathe in the dust. G10, for example, is bad news for lungs, from what I've heard on other forums. Better safe than sorry...

    AcydFlames Empty Pockets

    Definitely! Carbon fiber, plastic, fiberglass, all horrible! Can seriously cause many problems, wear at least a simple mask, if not full resporator gear. Any sanding, grinding, filing or cutting can create micro dust that can get absolutely everywhere! Just be aware, and be safe (as you sharpen your Courthouse Infiltrator® ;D) But for me, personally a fine toothed hand file could be my choice; I love the handtools though. Power would be quicker though.
    • +1 Supporter

    KeyGrip Loaded Pockets

    Good point, Codeman, I should have brought that up.

    ballistic Empty Pockets

    I used fine grit sandpaper on my AG Russel CIA Letter Opener, Cold Steel CAT Tanto and Delta Dart. Haven't sharpened my Blackie Collins Auto Stealth folder or my Busse Stealth Hawk.

    [img width=640 height=480]http://lh3.google.com/zodiac2/R31-oqvDoSI/AAAAAAAAABg/g5bABZtYoJ8/s800/P1020443%201.JPG[/img]

    Busse Stealth Hawk Trivia. Not your average cheap plastic knife ;):

    AmbuBadger Loaded Pockets

    Thanks to all! I knew I could rely on you guys, hard to find an on-topic forum such as this that isn't cluttered with mall ninjas...

    AcydFlames Empty Pockets

    I bet they're here too. They just lurk more ;D :lurk:

    0dBm Loaded Pockets


    Interesting product. I wonder if parts of it would melt while placed on the dashboard of a vehicle parked out in the open at noon on a sunny day in Palm Springs, CA in mid-August.

    stillphoto Empty Pockets

    I know I read somewhere when making a G10 credit card sized knife for the air marshals, a govenrment contractor had to use a diamond coated bit to get a decent edge on g10.

    I had a few custom built carbon fiber kiridashis made a while back. The maker said to use the top edge of my car's window to sharpen it...Said that would work on lots of knives. I'll be damned if it didn't work. Think about it, nicely radiused, sort of flat finished...very similar to the fine stones of a sharpmaker. Just have to get the angle right.

    [img width=640 height=480]http://i55.photobucket.com/albums/g136/Stillphotog/USN/kiripair.jpg[/img]

    ballistic Empty Pockets

    The material is similar to G10, but much more durable. It's not going to melt on a dashboard. The dashboard will melt before it does...

    Codeman Loaded Pockets

    Nice kiridashi's!

    Using a car's window is more akin to stropping that sharpening, as it doesn't so much sharpen the edge as it aligns the microserrations. Regardless of what it's called though, it is a good way to touch up a good edge.

    souptree Loaded Pockets

    Those are sweet kiridashis! Who made them and are they still available?

    Stutoffee Loaded Pockets

    Those Kiridashis do look great.
    Even though theyre now ULTRA-Illegal over here (but what isnt!!??) I have afew FGX items, & some small sheets of very thin carbon fibre that could probably make a handy little blade, perhaps something along the lines of one of those SOE thumb/lapel daggers.

    Sigh! Yet ANOTHER ruddy "project!" (Theres just not enough hours in the day!)

    VT-aroo Loaded Pockets

    untra-illegal, that is quite a catagory. All plastic knives?
    Our way goofy state allows a person to have them BUT you must put a metal ring in the lanyard hole and swear not to remove it before you go through the metal detector