My friend Dave, aka "Barty" had brought himself a new kukri but decided that the sheath it came with was far too nice for work. He therefore decided to make a simpler sheath. How he went about it was very simple, but the result was rather nice. Some knives, such as machetes don't come with a sheath. Other sheaths are just not up to the job or wear out. Since I know a couple of knifemaker's who find making a sheath a bit of a chore, I'll reproduce Dave's method here.
Get yourself a sheet of plywood, thinner the better and mark out the shape of the blade and then add about 15mm border all round and cut out.
Having done, this cut out a pair of sides the size of the border piece.
Glue the border piece to one of the sides and place the blade in it.
Due to the shape of the blade you may have to shave the inside to allow the blade to slide out properly.
When you have done this glue the second piece onto the other insuring that the thickness of the blade is less that that of the border piece (it will get stuck, if so split some of the ply and make a spacer (I had to do this)
Having done that and the glue has set, finish off, first the sides then the edges.
For extra strength I bound the top as this is a stress point. You will have one very strong and durable sheath. I then varnished it (yacht varnish it is stronger and flexible)
Dave adds- "I used six mm ply and just Unibond "water-proof" glue. It is up to the individual to what they use as long as it is strong. I mean kydex is good, even thick plastic. It's the spacer which is important and cover with what you like, i.e. leather, canvas."
This is a very simple way to make a very nice sheath. Dave mentions Kydex, and suggests this method as a way of making a sheath without having to mould the stuff in an oven. Personally speaking I like the suggestion of using Plywood. Using plywood gives flexibility and simplicity, and is probably cheaper too. Plywood is more resilient than solid materials such as block wood and the result, as can be seen from the illustration, is quite attractive. Dave's sheath was built ot hold a kukri. Sheaths for smaller knives can be made of thinner material and with less of a border on the middle section. The basic sheath described can be decorated in many ways. Strips of veneer or other decorative inserts can be added to the public side. There are lots of variations to this basic method. You can construct the middle layer with smaller off cuts of wood, or make this part of a material of a different colour. For a sheath for a machete I'd use a two pieces of plywood slightly longer than I need and 12mm wider than I want the front and back to be. The two extra 12mm strips would be used to make the sides of middle part and a little of the excess at the end the bottom part. Being a "belt and braces" type where some matters are concerned I'd use small decorative nails to hold the three parts together as well as glue, and rivet any projecting ends. Drilling holes through this part and securing with pop-rivets is another option. I'd also add a drainage hole either to the "private" side or through the spacer part at the tip. Simplest way to do this is to just leave a gap near the lowest part of the sheath when you are constructing the middle piece.
My friend Ed comments:- "With the glues available today, this 3-piece design would yield a very strong scabbard, no doubt about it. You can use a very similar approach with leather, perhaps substituting a tough polymer material for the strips of the middle part, and, I suppose, helping out the glue w/ cobbler's nails or stitching . I've observed that my replica kindjal scabbard is made of just two pieces of wood, routered out and held together (I hope) with glue and an outer wrap of vinyl. Seems sturdy enough, but I could wish for something more like Dave's design; can't get enough strength in a wooden scabbard. If I could score fine hardwood ply or laminated walnut, I'd never apply varnish, just finish with oil and mucho steel wool, the way I l'arned to finish a stock from m' pap. You could also make the spacer layer a different colour or material to the rest"
Dave's sheath was built for a kukri, which is probably one of the most difficult knives to build a sheath for. Building for a straighter blade will be much easier. For a thin blade such as a machete you can probably make the sheath with just two parts. Trace out the outline of the blade on a piece of wood. Then score down that line about 1.5mm deep with a stanley knife, or cut it with the router attachment on a dremel. You now remove the excess wood between the lines with a chisel or other suitable tool (like the Dremel with a different bit). Repeat this cutting along the line and removing the wood until a depression as deep as you want is created. You can either create this on both sides or twice as deep on just one side. Glue the two halves together and when dry shape the outside of your sheath.
For a curved blade you'll probably have to work out the radius of curvature. Visualized the centre line of your blade and trace out two lines perpendicular to it, one from near the guard, the other from near the tip. Where these two lines cross is the centre of arc. Place a stick or peg here. Loop the end of a piece of string over the peg and have the string just long enough to reach the edge of the blade at its widest part. Use this to draw an arc. Lengthen the string a little and draw a parallel arc on the other side of the blade. This is the basic shape of the sheath for a curved blade (or a good starting point!)
Dave adds:- "to help here is a rough sketch of what I mean in its making, this will also help explain why you have to check the fit on the Kukri Blade with its bend, so it can slide in and out. But this problem doesn't exist with a straight blade"
A very nice book on making handles and sheaths for knives is Bo Bergmann's book "Knife making" published by Lark books. From this book we get a very simple but secure design to add belt loops to your sheath. The hanger is quite simply made by twisting/twining two lengths of leather or cordage together. Once this is done the ends are tied in a reef or fisherman's knot, pulled tight and bound together with glue. The knot is not going to come undone, and it is highly unlikely both strands should wear through at the same time. A sheath such as that used for Dave's Kukri could be carried on two such hangers by passing them through holes drilled in the border pieces.
UPDATE A while back Dave sent me a knife blade which I recently fitted with a handle, and I decided to make a plywood sheath for it too. The Plywood used is thinner than Dave used for his Kukri, but it was free, and is sufficient for this sort of knife. I had to remove some of the material from the inside of the sheath with my Dremel, and the pieces were then glued together with Woodglue and left overnight before further work was done. I found the best tool for shaping the sheath was the Dremel with a High Speed cutter such as #115. The edges of the plywood seemed to quickly wear down or clog the sanding bits. Sheath was finished off with sandpaper and several applications of Linseed oil. Below is the final result; a little crude, but not too bad for a first attempt and scrap materials:-