[TUTORIAL] How to make a kydex sheath with a firestarter?

I will show you my way of making a kydex sheat. It will be a sheath for a bushcraft knife made by a polish knifemaker TLIM. The sheath will also have a firestarter holder and a cordura belt loop. Kydex gauge is 0.080 inch and OD green color.
Lets begin...

CHAPTER 1 - Designing and forming a kydex

On the begining I always make a simple concept drawing with a pencil. But you have to remember that it is preety sure that the sheath make of one piece of kydex will look slightly different than the drawing. It is hard to guess precisely how the kydex will look after forming.

I draw the lines and cut the kydex with a knife. The concept drawing helps me to mark how much kydex I have to use. It is always better to use more kydex because it will shrink a little during heating and it is easier to work with larger piece of material during forming and cutting the final shape.
One or two strong cuts with the tip of the knife and the kydex is easy to breake in hands.

One of the most important things in making a kydex sheath is preparing a knife for forming. Many people
forget about that step and it is a big mistake, because it is now when you can decide about many important issues:
  • how well will the kydex fit (when a sheath fit very well there is no movement when you shake the sheath with a knife and you can carry it upside down),
  • how difficult will it be to take out the knife from the sheath and put it back,
  • will you sheath scratch your knife ;)
  • easy cleaning,
  • how fast will a sheath dry (whitch is especially important when the kydex is made for a carbon steel knife, like that bushcraft knife).
I want to make a sheath that will dry very fast, will be easy to clean, the knife will fit very tight in it and the knife will not be scratched by the sheath. That is why I am making all the preparations.

    I am using a piece of brass rod and put it on the tip of the blade to form a 'channel' for the water. I usually smash the rod before mounting.And make two cuts with a a file so it will fit to the blade.
    I use paper tape (painter tape) on the blade. Usually 3-4 layers for each side. Thanks to that the blade will not touch the kydex so it will be much harder to scratch! Everyone know how annoying it is when every time you put a knife to the sheath it gets scratches because a small grain of sand fell into the sheath..
    I also use one piece of paper tape to mount the leather form to the handle. Remember that on the handle should be as less tape as possible because the sheath will be hold by a shape of the handle.

    Cut the tape with scissors and the knife is ready for a forming proccess.

     This is how my kydex form looks. It is very simple, made of two boards connected with a piece of leather. The molding foam I used is in fact foam sleeping pad which is very cheap and works very well. I put it to the boards with a paper tape. After too many uses I just replace two layers of  foam with the new one. But it can really take a lot of uses.

    All the tols that I use for forming. Material gloves are used to protect the hands because after heating kydex is very hot. I am using material, cotton gloves instead of plastic gloves because it better stands heat. Typical plastic gloves will just melt after touching the hot kydex.

    I heat the kydex with a kitchen stove, whitch is usually used to bake food. I am doing it very often. When someone is making a lot of sheats, should of course buy a dedicated stove. I heats tho stove to the temperature of about 140-150°C and when I got a temperature needed I put the kydex in. It should be 'baked' for about 15min but I am always checking if it is soft enough.

    When kydex is ready I just bend it over the knife and try to close the press as fast as I can. I am using 4 bar clamps and squeeze the press really hard. It should took about 5min for the kydex to cool in the press.

     CHAPTER 2 - Making the shape

    This is what I've got after forming. It looks like it formed really well, but as you can see, it looks a little bit different that on my first sketch. I am using a marker to draw the shape I want to get.

     I don't have a band-saw so I am using a hacksaw to cut the kydex. It is very easy to cut but also very elastic so I mount it in a vice.

    The shape is cut roughly ...

    ...and now it is time for some grinding. I am using a small belt sander with a belts of about 60-150 grit.
    After grinding.
    To finish all the edges I am using a fine grit sandpaper. I like the edges to be smooth and round.
    Another very important thing - cleaning. When I am working with the sheath I clean it with a running water every time I want to put a knife in it. This is because there is a high probability that some of the grains from sandpaper fell into the sheath during grinding and it can scratch our knife very badly... Sometimes I put a crushed tissue or paper towel to the sheath during grinding to prevent that. Always make sure that you have a clean sheath before putting the knife in!

    I will show you how I make a thumb ramp to put off the knife easly with one hand. This is the tips that I learned from a tutorial made by another knifemaker and is very helpful to me. I want to heat only a fragment of the sheath. That is why I am using a heat gun and a pail or pot with a cold water to prevent other fragments of the sheat to get hot. Also a marker to form a nice round shape of the ramp.

    I put the sheath to the water like this and start heating. When it is soft enough I put it outy and...

    ...form a ramp with a marker or any other round object. After that I very quickly put the knife to the sheath and sink it in the cold water to cool and get hard again.

    We have a nice round ramp. The shape of the sheath is now finished so I made one final step...

    ...and use buffering wheel to smoth all the edges.

    Nice and round :)

    CHAPTER 3 - Drilling the holes and puting the rivets

    Some people drill a holes before grinding/cutting the shape. Other cut the shape and after that drill the holes. Both methods have its prons and cons and I am using both of them with different sheats but in that particular sheath I am making the holes when all the edges of the sheath are almost ready.

     I am using a pencil and... some sticks (or anything else close at hand can be used) to draw a line equidistant to the edges of the sheath.

     I don't have any special drills to make a holes in kydex. I am usind drills for metal and that is why it is very important for me to puncture exactly where the holes have to be made. With an awl it is very easy to puncture the kydex. I am using the line that I drew with a pencil (it is hard to see on the picture).

    Now I take a small diemeter drill (2-3mm) and drill a little holes with my hands. Just enough for the bigger drill to enter the material in the right position.
    When kydex is well prepared for drilling there is a small chance that the holes will not be in the right places. I use that technique every time when I am making holes in a kydex or any other plastic material.

    Drilling is the simplest part when everything is well prepared. Put the sheath on a piece of wood and start low-speed drilling.

    All holes are drilled.

    To smooth the edges after drilling I use hard rubber polisher, but many other tools can do that - a bigger diameter drill, countersink, dremel grinding stones...

    I am using two types of rivets: 3/16 and 1/4 inch. In this sheath I will use the small ones. On the picture you can see all tha tools needed to set the rivets.Hand setter set, a hamer and a vice which will act as a anvil.

    The set have to be done with one or two strong hits. I have learned that tho more hits you make, the wors is the effect. Note tthat a rivet can breake and it is preety common when you are using a hammer.

    Kydex sheath after riveting. Most of people ends making a sheath on this step. You can mount a tek-lock or other ready made mounting system.
    Of course for the tek-lock distances between rivets have to be appropriate - 1 inch for small tek-lock and 1,5 inch for big tek-lock.

    ...or you can make your own belt loop as described in Chapter 4.

    CHAPTER 4 -Making a cordura belt loop

    I am not a big fan of tek-locks so I always make some kind of belt loop to my kydex sheats. I usually use  leather or cordura because I like the loop to be elastic.

    The loop have to be mounted to something. so I am cutting of a rectangular piece of kydex.

    That flat piece of kydex have to bend now. To do that I am preparing three wooden slats with rounded edges. The picture show how it will be formed.

    Once more the heat gun is your best friend.. When kydex is soft I use my slats to form it. I put it between the slats and wait for a couple of minutes for the kydex to cool down.

     After forming. Edges needs to be rounded.

    I drilled 4 holes so the sheath could be carry on  left or right side. Also edges are rounded and smothed on buffering wheel.

    I use a cordura sheet and cut a piece of material I want to use. To prevent cordura from fraying I scorch the edges with a burner or match. It is the same as scorching paracord and works really well. Picture on the left shows cordura before scorching.

    After scorching I join the kydex with cordura using a bar clamp, and drill both at the same time.

    After drilling holes in cordura it is frayed. The edges have to be melted.

    I am using brass tube with appropriate diameter to melt the edges. The tube is heated with a burner first.

    Now it looks better.

    This time I am using 1/4 inch rivets and join the cordura and kydex together.

    OK, we have a sheath and a belt loop. One more thing is needed - a firestater.

    CHAPTER 5 - Making a firestarter and a holster

    You need a piece of micarta, wood or G10 and a firestarter rod.  This time for the handle of firestarter I uses a piece of brown canvas micarta.

    I drilled a hole in the center of the block. Also grinded the edges of the rod on one side so it will not be round and fit better when making a joint with  an epoxy glue.

    I made a hole for a loop and use a belt grinder to give it the shape I want.

    Rounding the edges with a belt grinder and a sandpaper in hand. It is now ready to be glued.

    I put some 5min epoxy glue to the hole and put the rod in. After a couple of minutes we will have a very strong connection between rod and the handle.

    Now a holster. Once more I am using a heat gun to form the kydex. My form was a 6mm drill because my firestarter was also a 6mm in diameter rod.

    I didn't make a photo of it but after forming, the holster was grinded, edges rounded and two holes were made with a drill to mount to the sheath.

    CHAPTER 6 - The End

    Here are photos of the finished set. The firestartet fits very tightly but after hundreds of uses it will get thicker so I use a shock cord to mount it to the sheath. There is no way that it will slipped out from the holster.


    1. Very good tutorial. I've bookmarked it for future use.

    2. Fantastic tutorial. Thank you.

    3. This comment has been removed by a blog administrator.

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    5. This is very informative post about outdoor survival knife. Here are the more tips about kitchen knife. Thanks for sharing this post.

    6. This comment has been removed by the author.

    7. How big does a drain hole need to be? I also want to use .080 kydex and 1/4" rivets. Are all rivets the same length? I think 1/4" is the standard hole diameter for belt clips. Is it hard to remove a cracked rivet? I don't have a belt sander and drill press. Can i get by with sand paper and dremel tool and hand drill? Do you recommend brad point bit or can get by with a regular? I assume the bit will be same diameter as rivets.