Forming Kydex

[Bill Harsey]

This thread is about forming kydex.
I'm not sure where to start so here is the first simple thing I thought of to try and make things easier.
When one is forming kydex in a press around a blade, there has to be some relief between the blade and the Kydex or else the blade will pinch going in and out of the finished sheath.
Many years ago I was shown by Bob Terzoula how to put tape on the blade until we have something like thirty or so thousands of an inch thickness before placing the blade and handle in the press for forming the Kydex.
If your interested in thickness's and want to put the micrometer on some tape, fold one short length of tape over and then measure the thickness with the micrometer. This keeps the "mike" from sticking to the tape. Divide that reading in half and you know the thickness of each layer of the tape used.
Or just use four or five layers of good quality blue masking tape. It comes off easier. Place tape straight up and down the blade, not around.
Using a sharp hobby knife, trim the edges of the tape right next to the edge and spine of the blade. This way the tape doesn't "print" through the kydex and show on the outside.
I have never placed tape on the handle.

Handling sharp things can be hazardous to your band-aid supply!
Especially when removing tape from sharp edges. This is not theory. Work slow and with care removing tape.

[Bill Harsey]

Kydex is a thermal forming plastic used for a lot of things including interiors of commercial and private aircraft.
A heat source is handy for thermal forming kydex. I use two of them, an oven capable of holding 300 to 400 degrees F and a heat gun for doing area forming, like in belt loops or final forming the top of the sheath around a handle.
"Not too thick" cotton gloves help while picking up and working with the warm plastic.
Here is a technique used around here: use scraps of sheath leather as a thermal mask to protect areas you don't want hot when hand forming details with the heat gun. This is very useful.

[PiterM]

Good thread! I'll try to share some of my thoughts about kydex as well, sure :D

Let's talk about tape on the blade... yeah, that is of course very important step. Masking tape is best, I use TESA brand (popular here in EU, good quality and THICK) and I use 2 layers usually. Sometimes 3 layers (on knives made of more than 0.2" stock). One "trick" that I use is to put final tape coat with thin transparent packing tape. Masking tape is usually not glossy, so when you press hot kydex against the masking tape that creates "micro-texture" on the inner side of the sheath! For most knives it doesn't matter that much but for very fine satin finished blades YES, IT DOES. Glossy & smooth packing tape is very thin (so it doesn't change the thickness of the tape padding in fact) but it leaves the inner side of the sheath mirror-smooth. That is a trick I use on some of the knives.

BTW, these two sheaths I made yesterday and in that case (very very fine satin finish as you can see) I had to use this trick to prevent that finish from scratching.

[Smokin Joe]

I have just a quick safety tip:

Heating Kydex for too long or at too hot of a temp can cause a very toxic gas.
Rule of thumb if it starts smoking don't breath the gas!!!

I usually heat a sheet for 5-6 minutes at 300 degrees, at that heat and duration it usually comes out of the oven as pliable as a sheet of paper. Take this with a grain of salt I do not even rank as an amateur when it comes to making anything out of kydex. But I try and have done some reading on the topic. :cool:

[Trip_Wire (RIP)]

PiterM:

Nice work! ;)

[mcarey]

First as many of you know, not all sheaths are functional.

Proper planning for intended use is where I start for our sheaths (And that is not easy to accomplish if you want versatility). We are finding that making a multi funtional sheath is no easy chore.

So give these questons some thought......

What do you want to attach to? (Pack, belt, Molle/ PALS, a combination, etc...)

What orientation? (R/Hand or L/Hand; Vertical / Horizontal / complex angle)

What type of retention do you want? (2' drop, one hand draw, secondary retention)

What hardware is available?

What is your target cost?

I would be interested in what are the basic needs that you guys want for a field / combat knife.

[mcarey]

Here is a pic of our current Spartan Sheath.

We decided to have a removable belt loop, so the user can wear it or remove it. The eyelets match all Blade Tech (Tek Locs / Molle Locs) hardware, or the user can lash with 550 cord to pack, vest or other. Also, passes an inverted 2' drop test to insure good retention. Drain hole integrated to wash it easily. Also, shaped to allow for indexing and just a thumb push to release when drawing the knife.

We tried to meet most users needs as this is for general consumption. Your thoughts?

[Bill Harsey]

Thanks for the information, great stuff.
Piter, I'm going to try the tape thing (if I hang out here long enough, might eventually learn something)

OK, first question: Why do we use Kydex?

[HOLLiS]

Yes! Thanks for the information. I saved the link from a long time ago, to buy the tools needed to do this. I hope to be able to try this. I have to wait till I am finished build some new cabinet to fit into our current remodeling project.


Hollis.

[AF Doc]

Great thread. Kydex is strong, protective, does not absorb water, can be molded to create a secure fit for a specific application. All good.

It is also noisy. When out it the woods, the sound of a pack buckle or rifle sling hitting a kydex sheath makes a distinctly unnatural sound that seems to carry for miles. (Even a stick or rock scraping a sheath can be noisy.) I like my Kydex covered in a noise dampening material (typically nylon).

Just my $0.02 (AF script)

[MasterOfMyFate]

I Google'd "kydex" and came across another material called "concealex"... Anyone heard of this? I hadn't until then. I saw it on a knife-making supply site. They had both kydex and concealex. Concealex was the more expensive, and came in thinner sheets. I checked Wikipedia to try and find some info, but came up empty.

[mcarey]

Kydex is a tradename for colored, finish grade, ABS plastic sheet.

Boltaron and Concealex are similar products that can be formed in the same manner.

[Smokin Joe]

Thanks for the information, great stuff.
Piter, I'm going to try the tape thing (if I hang out here long enough, might eventually learn something)

OK, first question: Why do we use Kydex?

It is realatively cheap, easy to form, requires little (skill or equipment) to work with, and if you screw up a mold you can place it back into the oven for reshaping. So, for me it is almost ideal to work with due to my limited abilities.

[Ken Brock]

interestingly enough, I usually don't use tape on my blades

if making sheaths for another maker, it depends on the finish on the knife


kydex is pretty easy to work with and makes a good sheath material


for years I used Boltaron, but then they stopped making it available in my chosen thickness and when I called the company to talk with them, they were dicks so I switched to kydex

[Bill Harsey]

Yep, You guys got it.
Many use Kydex because it is very cut proof. All the nylon web sheaths we use for our fixed blades have kydex inserts that are screwed on at the pointy end.
This is so the edge of the blade will not cut the nylon fabric.

Kydex forms nicely to the shape of the blade even if Mr. Ken Brock always has to do things his way. ;)
Ken, I've found I have good fit up until putting the sheath together with the final rivets then it sometimes gets too tight. This is why I use tape.
I use Cleco fasteners to test fit up my sheaths before final assembly. The Clecos are a temporary spring loaded fastener used in the sheet metal and aircraft building trades to position stuff until it is final fitted.

Another thing to consider when forming Kydex is that thin Kydex will cool much faster than thick Kydex. This means we have less time to handle the thin stuff when trying to position everything in the forming press.

[Ken Brock]

=

Kydex forms nicely to the shape of the blade even if Mr. Ken Brock always has to do things his way. ;)
.


Mr. Harsey, you know I always do things the hard way! (ie. the redneck way)

[CPTAUSRET]

Excellent thread, guys! Y'all are schooling me.

[Bill Harsey]

Excellent thread, guys! Y'all are schooling me.

Let us know how far away you have to stand from the jet exhaust to get a good heat on the Kydex. :D

Had a question about where to get the Cleco fasteners for test fitting. These work so good I should have kept this classified.

I got mine from Spencer Aircraft or spenceraircraft.com
The phone is: 253-848-9349 and the last time I spoke with them, there was no minimum order.

If you use these, you will need the Clecos in the correct size for your rivet holes and one Cleco Pliers hand tool for inserting and removing. They are not usable without the pliers.

[NousDefionsDoc]

This is real good. Can you explain the process to putting the belt loops on when you get a chance?

[Bill Harsey]

This is real good. Can you explain the process to putting the belt loops on when you get a chance?

Belt loops will add extra thickness to the "stack" (combined thickness of all the layers together). The first thing I would do is make sure I have rivets or bolts long enough to hold it all together.

Hole layout is next. Belt loop has to be wide enough to hit the hole locations on the sides of the sheath. Choosing hole locations is important as we work at the top of the sheath because this changes how the sheath works if it is a clamping fit around the handle and guard area. The closer the rivet is to the top, the shorter and stiffer the spring tension of the Kydex is.

Accurate hole placement is important. I layout on kydex with a silver pencil then use a sharp locating punch to indicate the center of the hole. Do not drive the punch all the way thru the Kydex.
Next step is drilling a pilot hole with something like 1/16th or
3/32nd inch drill then using the final size drill, like the 3/16ths inch. The pilot hole keeps the drill centered as drills tend to "walk" all over the surface of kydex when starting.

If the belt loop is being added to an existing sheath, one might want to remove the top rivets to use the same holes for the belt loop attachment. I do this by drilling through the top of the rivet with a "just barely" big enough drill. If the rivets are in 3/16ths holes, I would use 3/16th drill. Drill until the top web of the rivet is gone or can be peeled away. Push out remainder of rivet with something. Do not try and drill all the way thru.
Some Kydex sheaths are made with larger bore rivets to allow bolting a belt loop or other type attachment onto the sheath later.
Edited to add:: Do not drill these rivets out.

I'm pretty sure I missed answering any of the important questions, so lets keep going.

[Bill Harsey]

Paper patterns and pencils are the first tools I reach for when doing either Kydex or leather work. Should have posted this at the beginning but it still applies to belt loop work.
This is how I get my brain focusing on the job at hand while sometimes finding and solving problems before trying to fumble warm plastic.
Fold the paper exactly how the belt loop is to be shaped, use a ruler to make folds exactly where they are wanted. If this is not to the makers liking, get another piece of paper. Draw the hole placement in paper pattern. Test fit the paper pattern.
For leather work I've been Scotch taping more paper onto the pattern if needed instead of starting all over. Transfer the paper onto the kydex with the silver pencil. Use your very sharp pocket knife to keep a good point on this pencil. This helps a lot.

[Ken Brock]

Mr. Harsey sir, you put wayyyyy more thought into the sheaths than I do!

:D:cool:

[Bill Harsey]

Mr. Harsey sir, you put wayyyyy more thought into the sheaths than I do!

:D:cool:

Sorry.

Ken,
How do folks cut out Kydex if they don't have a wood type bandsaw?

[The Reaper]

Not Ken, but wouldn't a saber saw or jigsaw work?

You could even use a fine toothed hacksaw if you had to.

TR

[Razor]

You could even use a fine toothed hacksaw if you had to.

BTDT. It works, but its tough to cut sharp angles due to the width of the blade.

[Ken Brock]

Sorry.

Ken,
How do folks cut out Kydex if they don't have a wood type bandsaw?


I use a set of tin snips to cut kydex before it's formed


after I form the sheath, I generally use a saw to cut off the excess although the tin snips can be used to cut through the double thickness.

I'm using .080 kydex exclusively right now

[swatsurgeon]

I can vouch for Ken's work with kydex....despite the fact he can do it blindfolded, intoxicated, behind his back, his work product was excellent.
See Ken, I am your biggest 'kydex' fan!!

ss

[Ken Brock]

I can vouch for Ken's work with kydex....despite the fact he can do it blindfolded, intoxicated, behind his back, his work product was excellent.
See Ken, I am your biggest fan!!

ss


I've never been blindfolded!:D


but thanks sir for your kind words

[Smokin Joe]

Sorry.

Ken,
How do folks cut out Kydex if they don't have a wood type bandsaw?

Dremel and final sanding is done with the green side of the wife's used dish sponge.

[Kyobanim]

For a person interested in learning how to work kydex, what would be appropriate as a test item to start off with as a learning experience?

Also, would a coping saw work as a good cutting tool?

[Smokin Joe]

For a person interested in learning how to work kydex, what would be appropriate as a test item to start off with as a learning experience?

Also, would a coping saw work as a good cutting tool?

I started with a small pistol and a small fixed blade knife. Like I stated before I'm no professional, but I found that just jumping in there and mixing it up so to speak worked for me. As you know you can only read about something for so long for before you just have to try it. I also use a guarded optimistic ever evolving approach where I always try to learn more as I go. But trial and error has been a good instructor for me.

The best thing about Kydex is if you don't like what you made, you can throw it back in the oven for a do over (provided you haven't made any cuts or drilled any holes).

Just mix it up Kyo you will be amazed how easy it is. And if you want I have a crap "how to make stuff out of kydex" dvd I can mail you

-Good luck

[Bill Harsey]

For a person interested in learning how to work kydex, what would be appropriate as a test item to start off with as a learning experience?

Also, would a coping saw work as a good cutting tool?

Kyo,
I think the coping saw would be fine. Anything that works wood, works Kydex even easier.
Round rasps will cut the small corners, files and sandpaper work good on Kydex and medium steel wool is a fast way to finish the edges.

Ken, I'm going out to try the tin snips on some Kydex, never would have thought of that myself. I think if you measured Kens grip strength it would be somewhere between neanderthal and superman. Not sure if that will work for me.

Smokin Joe, you now own the first PS.com "Redneck Sheathmakers Award of the Year" for using your wifes "srubby" to finish Kydex. :lifter
Don't you folks have hardware stores at your location?

[Ambush Master]

The stuff on the green side of the sponge is Scotch-Brite. Very useful stuff and not real aggressive. We use it a lot on aircraft sheet metal work.

[Smokin Joe]

Smokin Joe, you now own the first PS.com "Redneck Sheathmakers Award of the Year" for using your wifes "srubby" to finish Kydex. :lifter
Don't you folks have hardware stores at your location?

Yahooo! my wife will be so proud of my new achievement. :D

Yes, but when I was in my old house (when I picked up working with kydex) I ran out of sandpaper once and used an old scrubby. It worked so well I just continued to use it. :cool:

[Bill Harsey]

The stuff on the green side of the sponge is Scotch-Brite. Very useful stuff and not real aggressive. We use it a lot on aircraft sheet metal work.

AM,
correct and Scotch Brite is aluminum oxide bonded to the coarse entanglement fiber that makes the stuff. Why is this good to know? Because if you use it to scrub bugs off your motorcycle chrome it will leave scratch marks. Same with knife blades.

Ken,
Tried the sheet metal snips last night on some tenth of an inch thick Kydex. Kinda tough to cut because the snips have smooth edges and it pushed the work away more than cutting it.
So I tried the aviation snips that had fine toothed edges and they cut pretty good but I'm sticking to the bandsaw:D.

[Ken Brock]

Mr. Bill,

the snips I use are advertised as tin snips but they have very small serrations. My forearms are pretty strong.......................from a lot of excercise


Ambush Master,

The way I finish kydex is to grind it to shape with a 60 grit belt and then finish with a Scotchbrite belt on my grinder

[modgod]

Dremel and final sanding is done with the green side of the wife's used dish sponge.

That's called scotch-brite :) I use it too as a machinist for fine finishes on aluminum and what not. The dish stuff is just a fine hair less abrasive then the lightest coarseness of pad Scotch-Brite actually sells to the industrial suppliers. Works wonders as well when used with plastic polish to get a really nice and professional looking semi-opaque finish on acrylics and most of the clear thermoplastics that I work with. If you can cut a disc of it (little sponge left is ok, or just buy the pads) and attach it to a dremel, it also works wonders for getting a high-gloss transparent finish on those same plastics, with liberal use of plastic polish and careful mind to turn or mill it correctly and use the right cutting fluid (mineral oil actually works best).

As for cutting Kydex for the rough work, I've successfully used the wood saw on my Leatherman Charge to good effect, works on PVC sheet as well. The shortness of the blade combined with the good grip from the leatherman actually makes it my preferred tool for remnant cutting for rough work. I don't make sheaths, but I've done ALOT of thin plastic work. The only down side is that the blade cuts at 3/16 thick, which leaves a lot to be filed/sanded/polished down. Only works for stuff 1/8 and thinner, more than that and the material keeps binding the saw when it flexes.

[Bill Harsey]

modgod,
Good thinking.

I've used hacksaw blades with the back ground off to slot Kydex for pancake style sheaths (starting in the pre drilled holes of course). One can go to the hardware and get the finer cutting jigsaw or other "up 'n' down" cutting blades and use a medium pair of vise grips for the handle. Lots of blades to choose from now.
Remember the vise grip handle, works better than it sounds.

[Bill Harsey]

This is real good. Can you explain the process to putting the belt loops on when you get a chance?

Did any part of this question get answered yet?

[Smokin Joe]

Bill,

What are your thoughts on a scroll saw for cutting/shaping kydex?

[Bill Harsey]

Bill,

What are your thoughts on a scroll saw for cutting/shaping kydex?

I have one but have never tried it for cutting kydex. The scroll saw blade needs free space under the cut and this would have to be considered when trying to hold a relatively small work piece and the saw all in the correct place while running.

Other than that, I'm pretty sure I could make it work with the right blade and if it was the only saw I had, it would be cutting kydex for sure.

[Defender968]

I'm interested in making a sheath for a Gerber Mark I and am thinking about using Kydex, do you have any recommendations as to where to get it from online?

[Smokin Joe]

I have one but have never tried it for cutting kydex. The scroll saw blade needs free space under the cut and this would have to be considered when trying to hold a relatively small work piece and the saw all in the correct place while running.

Other than that, I'm pretty sure I could make it work with the right blade and if it was the only saw I had, it would be cutting kydex for sure.

So what you're saying is, it would be a royal pain in the ass huh? Okay I'll get a band saw instead. :D

"Hey honey, Bill said I HAVE to get the band saw instead. Look it says so right here on PS.com..."

[mcarey]

I'm interested in making a sheath for a Gerber Mark I and am thinking about using Kydex, do you have any recommendations as to where to get it from online?

You can try a couple sites that I have linked below:

http://www.knifekits.com/vcom/index.php?cPath=41

http://www.northcoastknives.com/northcoast_knives_Supplies3.htm

http://www.texasknife.com/vcom/index.php?cPath=37&osCsid=ddca9777dcd1cf03f96f04a3eb2ecb46

Hope those links help.:cool:

[bravo22b]

I have no experience with Kydex, but I have had to use a pair of linesman's pliers and/or Vise-Grips to hold a saw blade once or 100 times.

A great, pretty cheap tool to have around is a jab saw handle, like this:

http://www.stanleytools.com/default.asp?CATEGORY=SPECIALTY+SAWS&TYPE=PRODUCT&PARTNUMBER=15-033&SDesc=Jab+Saw

You can put just about any blade in it, jigsaw, hacksaw, sawzall, etc., and makes life a lot easier, and save the Vise-Grips for what they do best, completely rounding off bolt heads.:D

[Razor]

I've bought several items and kits from North Coast Knives and have had very good service through them. Their tutorials were very helpful, too.

[Aubrey]

I'm gearing up to make some Kydex sheaths, magazine pouches, flashlight/multitool sheaths, and the like for my own use, and I've been studying the hole spacing required for the various mounting hardware. I've acquired a variety of Blade-Tech hardware including a large Tek-Lok (3/4" hole spacing), large and small MOLLE-Loks (3/4"), J Hook (~1.15" spacing?), rubber IWB loop, and a KnifeKits pre-formed belt loop (1" spacing). The supplier was out of small Tek-Loks when I ordered, but I it is my understanding that they use 1/2" hole spacing and that most folks accommodate them with 1" hole spacing on their sheaths.

I'd also like to acquire some Spyderco G-Hooks. I'm ASSuming their hole pattern is compatible with that of the small Tek-Lok (?).

Anyways... I was hoping to use an eyelet spacing that would allow a variety of standard mounting hardware to be used. Also, I would like the capability to mount my gear on PALS webbing, which is 1" wide on 1" rows (1.5" channels). I've noted that some folks on another forum have had mixed results with the MOLLE-Loks (e.g., some reporting that they have come unlatched) and others have recommended MALICE Clips as an alternative. Perhaps good ol' 550 cord is a better option (?).

I'd really appreciate some constructive feedback on what eyelet spacing is recommended and what mounting hardware has proven the most versatile, reliable, cost-effective, etc... Many thanks in advance for your help.

[cszakolczai]

For those who like to see things for themselves...

Part 1
http://www.youtube.com/watch?v=j7CsuKqRjeo&feature=related
Part 2
http://www.youtube.com/watch?v=L2z1KMbBFFQ&feature=fvw

Seems like a pretty nice walk through. Maybe someone who's worked with kydex can comment further. I'm going to try and make some magazine holders soon.

[x SF med]

Wow, I usually see if Brian over at Okuden can whip me up something... he seems to know what he's doing....:cool: my philosophy, "use the local resources"

[DJ Urbanovsky]

Here's my process for molding normal human sized knife sheaths. Swords, axes and holsters have additional steps. Again, this is just how I do it. There's more than one way to skin a cat.

Prepping and molding:

1) Cut an appropriate sized hunk of Kydex off of your sheet. I get all my Kydex pre-cut in 1'x2' sheets. I lay the knife on it and mark off with a blue sharpie how much I need. Line up the T-square with the tic mark, and then score it with a box cutter. Then bend and snap. It'll break at the score mark.

2) Wipe your blade with acetone, then tape it. For me two layers of thick blue masking tape on each side does the trick. I trim off the excess with a razor blade, leaving about an 1/8" extending past all edges of the blade. While you've got your acetone out, wipe down both sides for the Kydex as well.

3) Pre-heat your oven. I use a toaster oven. As has been mentioned, Kydex off-gasses, so it is advisable not to do this in your wife's oven. She will be less than happy.

4) I crank my oven up to broil. You can use a lower setting, but I monitor my Kydex constantly when it's in the oven, and I usually have a bunch of sheaths that I'm banging out so speed is a factor. DO NOT walk away from the oven when the Kydex is in there, regardless of how low you think your heat setting is. Trust me on this. ;)

5) When the Kydex is in the oven, I will check to see if it is ready for molding by grabbing a corner with a pair of hemostats and giving it a shake. You'll get a feel for how rubbery you like it for a particular project as you work with it more. If you get it too hot, it'll get shiny and the edges will start to curl. I always do mine cell side up so I can see if this is occurring.

6) Before you stick your Kydex in the oven, you want to make sure you've got your press open, clamp, and blade all staged. Don't forget to clean your press. Yank the Kydex from the oven, slap it cell side down into the press, lay your blade on the Kydex, position it appropriately for the style of sheath you're making, fold the Kydex over it, close the press, and clamp shut. Some guys clamp theirs in a vice, I prefer a big pair of C-clamp vice grips. More on the press later.

7) Leave it clamped up until the the Kydex cools down. How long that is depends on how hot you got it and the thickness of the Kydex. I usually go for about 18 minutes. Peel your now molded Kydex off of the press, carefully (it may not be fully rigid yet). It'll probably still be warm. Set it aside for another few minutes to air cool. Then split and peel the sheath apart. When I am molding, I will leave a tab of Kydex sticking out to facilitate this. Carefully withdraw the knife and peel the tape off.

That's it for the primary molding. After that, it's locating and drilling holes, setting rivets, cutting off excess Kydex, grinding and polishing the edges, cleaning, and final fitment tweaks with the heat gun. I'd be happy to explain my processes for that stuff as well, if anybody is interested.

Some safety notes:

1) Never force a knife into a Kydex sheath. If it's hanging up, pull it back out and try again.

2) If the knife won't come out of the sheath, don't white knuckle it. Go get your heat gun to loosen things up. I can show you pics of why you should not do this.

3) Do not wrap your fist around a knife sheath like you're holding a baseball bat. Blades will cut their way out. You will mess yourself up bad. Grab the spine of the sheath instead.

4) Observe how the sheath is intended to function before sheathing/unsheathing the knife.

The safety stuff may seem like common sense, but it is still a vitally important safety consideration. All it takes is one momentary lapse and you're on your way to the ER.

[Aubrey]

... I'd be happy to explain my processes for that stuff as well, if anybody is interested.

DJ,
Yes please... and thanks for taking the time.