20 May 2012

Personal Knife-Sheath

    I start the sheath by cutting the kydex to size on the table saw. There has to be enough to cover the knife with an area for the rivets and the hanger tab. The kydex is heated to make it pliable, when its hot enough (about 375 degrees F) it gets flexible and limp. The hot kydex is pulled from the oven, quickly wrapped around the knife and clamped in the press. Once the kydex is cool the press is opened and the sheath inspected to check the mold, rarely does it go perfect on the first try. If its not right, back into the oven to heat up and try again I have had to remold some sheaths up to 5 times, the kydex will flatten out in the oven and remold with no apparent damage.

   The next thing is to drill the rivet holes.

  I make my own hollow rivets from the same brass tube as I used for the thong hole liner. The tube is cut to length with a hack saw. One side is flared with a punch against a plate with a hole in it for the punch to pass through. Then its inserted into one of the holes in the sheath and then the other side is flared, this locks the tube into the sheath and lets the die turn the brass down without crumpling.

   The dies, which I made from steel rod and a drill bit shaft, are slipped together through the rivet and squeezed in the bench vice. The rivet is half formed and the vice backed off, the die reversed in the rivet, put back in the vice and the vice tightened again. It may have to be switched a time or two more. Since both sides of the rivet are being formed at the same time this switching keeps them even. The last squeeze is quite tight to flatten the rivets against the kydex.

  The access kydex needs to be cut off, I trim it close to the finished size on the bandsaw, then finish it up on the belt sander. One thing to remember if the knife is snapped into the sheath before the trimming is done it will be very hard to remove usually resorting to tying a cord through either the bottom holes in the sheath or the thong hole of the knife. Securing the cord on something solid and pulling the sheath or knife to get a controlled release of the knife from the sheath. This is much safer than muscling it out. 

   Using a heat gun, aluminum foil to insulate the part I don’t want to heat, an awl and a piece of kydex off cut I bend the hanging tab,

 flare the thumb ramp,

   and open up a drain hole.

  The edges need to be rounded and everything made smooth. A few passes across the buffing wheel cleans this up.
   Hanger and belt clip
   The belt clip is formed of heavier kydex, around a mandrel the size and thickness of the belt I will use it on.

   Two holes are drilled for the cord in the tab and in the hanger. I use a drill bit about the same size as the cord.

   The cord ends are heated with a lighter until molten then pushed into a die, which is just a drill dimple in a piece of micarta. This flares the ends so they will not pull out of the hole.

When cool the end is inspected for symmetry and held close to the flame to just melt the surface, this sort of polishes it.
   This method eliminates the bulk of a knot on the sheath and the hanger.
   The cord is threaded through the sheath and hanger ,the length determined, the cord cut and the cut end flared. The sheath is done.

   This knife with the long cord is designed to be hung from the belt and dangled into the front pants pocket. This keeps it out of the way and easily accessible: also the sheath is attached to my belt so its there when I go to resheath the knife.

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