Kydex sheath making

My Kydex forming experience is in the 10's not the 1000's but i wrote up a couple info sheets for myself while doing the research.

I know i have a couple more here but can't find em right now.

For those who are interested..

How to glue a Kydex sheath.

Concealx and Kydex materials are classified as Thermoformable Acrylic Polyvinyl Chloride (PVC). They are used mainly in the manufacture of interior panels for mass transit vehicles such as busses and aircraft. They are also commonly used in the manufacture of knife sheaths, pistol holsters and many other interesting uses.

Concealx is the trade name of BladeTech for the product Boltaron made by Empire Plastics.
Kydex is the corresponding trade name used by Kleerdex.


One very valuable feature of these materials is their versatility. They are highly formable and workable. They can be assembled with any standard mechanical fasteners such as screws or rivets, but they may also be solvent welded together. Solvent welding may be thought of as simply gluing the materials together, but there is a significant difference. Solvent welding actually partially dissolves both surfaces to be joined. Both parts are pressed onto one solid piece. This results in a strong, attractive joint, rather than two layers of material with glue in the middle.

The technical support department of Kleerdex recommends using Tetrahydrofuran (THF) for solvent welding.

Methyl-Ethyl-Ketone (MEK) is also mentioned as an additive to paints for spray application onto Kydex. MEK will improve adhesion by allowing penetration of the paint through the smooth outer surface.

One easily available product for solvent welding which can be used is Oatey’s “Orange-label” CPVC cement.
It is manufactured by:
Oatey
4700 West 160th street
Cleveland, Ohio
44135
1-216-267-7100

www.oatey.com

It is described on the label as a medium clear CPVC cement for CPVC pipes and fittings. It is commonly available in hardware and plumbing stores as plastic pipe cement. In the Oatey line, many products are available for different plastics that contain THF. I find that this is the best product, with the most compatible (clear) color. Other essentially identical products are also available from other manufacturers, this product just happens to be what I use.

Sand the interior (shiny side) of both Kydex pieces with abrasive to allow the solvent to contact and penetrate. I usually use a 220-grit abrasive cloth. Apply the cement sparingly on both sides; a small brush or disposable cotton swabs work well. The material will absorb the cement and soften slightly. Apply and maintain pressure on the assembly for 4 to 24 hours to allow the bond to set. Cure time will depend on, the material thickness, the amount of cement applied as well as the curing temperature and humidity.

Caution:
As with any chemical this has the potential to be hazardous if not used correctly. Read and follow the warning labels. As a basic summary- Don’t: drink it, breathe it, smoke it, touch it, rub it in your eyes, set fire to it, or give it to your children. If you did happen to experience one of those incidents listed, you are invited to call 1-303-623-5716 and reverse the long distance telephone charges for friendly and knowledgeable advice on how to best proceed.



Question - how do you finish the edges of your kydex? In other words, how do you get that slick look to the edges with a slightly rounded edge?

I'm also pretty sure that I read somewhere that you can use a bit of acetone on a rag and wipe it down the edge but can't find that reference again.

I believe the solvent used to rub the edges into a nice polish is the thinner used for the PVC solvent.


KYDEX:
Kydex is the trade name of and a registered product of the KLEERDEX Corp, and meets all military Specifications, etc.

The recommended temperature for working Kydex is 350* F.

CONCEALX:
Concealx is a trade name of BladeTech for the product Boltron.
Boltron is the trade name and registered product of the EMPIRE Plastics Company.

Boltron is less expensive than Kydex and meets most of the higher specification that Kydex meets
BOLTRON works at a lower temperature and cools faster than KYDEX.
The factory recommended temperature for most Boltron products is 290* - 335* F do not exceed 335*F.

The porosity of the BOLTRON acrylic PVC material caused an over all moisture absorption rate much higher than KYDEX. It should be pre dried at about 200 * F before thermoforming. It has no real effect on moisture holding as it relates to corrosion of the contained items.

Both materials begin to break down at temperatures of over 400* F and tend to give off some very nasty gases.

There are about 22 grades of KYDEX, but the two most common types that are used in the knife and sporting goods industry is KYDEX T & KYDEX 100. These two also are the most common used in the Aircraft and Mass transit applications. BOLTRON makes about 11 acrylic PVC sheet products but the most common usage is the BOLTRON 4330. For that reason these are the three products discussed.

TYPICAL PHYSICAL PROPERTIES OR EMPIRE/BOLTRON 4330 AND & KYDEX 100 SERIES. These figures are factory typical values.

Specifications BOLTRON 4330 KYDEX T KYDEX 100

Specific gravity 1.40-1.43 1.35 1.35
Tensile strength 5,000-5,400 PSI 6,100 6,100
Flexural strength 8,600-9,200 PSI 9,600 9,300
Impact resistance 15-18 15 18
Heat deflection 161-163 * F 168 * F 173* F
Mold shrinkage 0.5%-0. 7 % 0.4%-0.6 % 0.3%-0.5 %
Forming temp 335-370* F 325-390*F 325-390* F
FAA Approved Unknown PASSED PASSED
Absorption rate ** Unknown 0.006% / volume 0.006%



Quote from KYDEX information sheet;
GENERAL INFORMATION
Kydex T is a proprietary acrylic/PVC thermoplastic sheet that is cost competitive with fire retardant ABS/PVC (FR-ABS) formulations but with significantly higher impact strength and extensibility. Unlike FR-ABS, because Kydex T is less hygroscopic, Kydex T typically does not requiring pre-drying; offers superior impact resistance 15 ft-lbs/in (801 J/m); more uniform forming with less wall thinning; and offers significantly greater resistance to a broad range of corrosive chemicals and cleaning solutions. It is available in a wide range of aesthetic choices and is UL recognized Std 94 V-0/5V.


Quote from BOLTRON information sheet;
GENERAL INFORMATION
EMPIRE/BOLTARON 4330 Sheet is an ACRYLIC-MODIFIED POLYVINYL CHLORIDE extruded sheet, compounded with excellent balance of physical properties. Field-proven in numerous commercial, industrial, institutional and transportation applications, EMPIRE/BOLTARON 4330 Sheet also exhibits outstanding thermoforming characteristics and excellent mold and pattern reproduction (heats faster/cools faster), which means faster cycle times on standard thermoforming equipment. Empire Plastics information sheet also says that this product is rated as "Good" under the Weatherability category while the Kleerdex information sheet states that both T and 100 series rates as “Excellent” in Weatherability.


Steven Penner

I know this is lengthy, but i found some of it useful
 
Where is everyone getting the screws that I am seeing. I am ordering all my stuff thru knife kits.com and am interested is using these type of screws. They aren't Chicago screws are they!??

Thanks,
 
just google for them, you will find plenty of places with what ever size and color you need
-matt
 
chicago bolt/screw will probably yield best

for size what ever size hole you need and how big you want the tops

-matt
 
Now that I've done two I can give you my expertese !!! I had some silicone rubber foam which cerainly would take the temperature. Press ? I sat on it till it cooled ! To trim the kydex I used a aircraft type tin snips. Various files came in handy .Instead of screws or grommets I fastened it together by sewing with stainless steel wire !
 
Thanks guys for the info.... all the Chicago screws that I have found are flat tip..... the ones that I am seeing that I like are phillips head's//// what am I missing here?
 
I am very new here but have been reading several of the topics including this one. I made my first Kydex sheath last night with the help of this forum. I used the .080 guage(?) kydex. Some of the detail of the sheath is not as sharp as the ones that Normak posted pictures of. My questions are-

1) Is this just because of the thicker kydex?

2) Can I reheat and repress after I put in the rivets or am I just SOL?

This is my first project like this so be gentle :D
 
Hey Mike...

Please post some pictures and I should be able to give you more specific answers..

"1) Is this just because of the thicker kydex?"

Not always.. You should get decent crisp definition using 0.80.. A couple of factors can change this though...

1. Amount of tape used to mask
2. Pressure used...

I would lean more towards the pressure being used... you aren't using enough,, or it isn't equal pressure.... Is one part of the knife is pressed well and say the tip isn't,, then you have unequal pressure...

Other things can happen as well, such as "rolling" or "diving", where the tip sticks out deeper on one side...

Alot of things can cause this,, and is usually do to a worn out mould,, or a flexible mould.. If your mould flexes,, that can cause this....

I use a custom 2 ton press.. however I have no idea what kind of pressures I'm getting from it.. I mostly go by feel...

"2) Can I reheat and repress after I put in the rivets or am I just SOL?"

You can to a certain point.. If you are spot pressing,, that may be Ok,, however and heat applied to the eyelets once they have been set will distort the plastic around them,, and can push them out or weaken the mechanical hold...

All of your pressing should be done before you drill and set eyelets...

Hope that helps...

Eric
O/ST
 
Eric,
I think you are right about the pressure. Im sure that is what it is. As this is my first attempt at this type of thing, I do not have all of the equipment that I should. My press consisted of two peices of plywood w/ 2 peices each of foam camp mat. For the pressure I used a five gallon bucket filled with weights and water with me standing on top of it(hehe, low tech and inefficient, I know). I will pick up some proper clamps this weekend.
 
Hey mike..

Yes,, then that is Exactly your problem...

No where near the required amount of pressure if you are expecting much more definition...

If you are stuck and have an automotive floor jack...

Set yourself up in the garage or driveway,, jack the front end of your car up, and slide the mould under the tire and lower the car ontop of the mould.. LOL

Don't laugh it works in a pinch,, but BE CAREFUL !!!!

That is about the amount of pressure you will need....

Feel free to contact me directly if you have any specific questions...

ttyle

Eric
O/ST
 
I made a Kydex holster this afternoon. If anyone is interested I'll post photos of the process I use. It's the same process I use for knife sheaths. ???
 
I am very new here but have been reading several of the topics including this one. I made my first Kydex sheath last night with the help of this forum.

Pics. I like pics. :D

I used the .080 guage(?) kydex. Some of the detail of the sheath is not as sharp as the ones that Normak posted pictures of. My questions are-

1) Is this just because of the thicker kydex?

Obviously thinner Kydex will flow and form into smaller places than thicker, but overall good definition can be had with any guage. I use .093 and do alright.

Pressure is a big issue. I dont use anything special myself. Couple of 2x10s hinged, foam in between, and a ball joint press on the other turned with a 1/2"drive. I keep it redneck.

Heat: Kydex needs to be floppy when put in the press. Heat it with a toaster oven or your stove. A heat gun is essential for fit, but sucks as your main heat source.

Lubrication: This is often overlooked, but a good press requires good lubrication. I use store brand cooking spray. Spray the bejesus out of the foam.

2) Can I reheat and repress after I put in the rivets or am I just SOL?

Not the whole sheath. When I need a slightly better fit after a sheath is already made, I use the heat gun. I have "attachments" formed out of sheet metal that I use depending on the area. A wide flat attachment is used just to heat the blade area slightly and nothing else

This is my first project like this so be gentle :D

No worries. My first sheaths looked like they'd been ran over by truck.
 
I made a Kydex holster this afternoon. If anyone is interested I'll post photos of the process I use. It's the same process I use for knife sheaths. ???

Yes. :thumbup:
 
Kydex Sheath or Holster

I make patterns of the sheath or holster with AutoCAD. This means I always have a new pattern for each use. I am also able to easily tweak the pattern until it is perfect. This example is for a 1911 pistol. I also have patterns for Commander and Officer’s Model pistols.

I used .08” Kydex for this holster.


see figure one

I use a spray on adhesive to glue the pattern to the Kydex (just a little bit will do). Be sure your pattern is placed on the correct side of the Kydex. In this case the pattern is glued to the smooth side or what will become the inside of the holster.

The pattern is over-sized on the bottom and the left and right sides so I can trim to fit.

Then I cut and sand the Kydex down to the pattern (try to stay in the lines). I use a variety of tools to cut and shape the Kydex including tin snips, band saw, belt sander, files and Dremel.


see figure two

Now I can remove the pattern from the Kydex. I also remove any residual glue.

Next I will heat the Kydex down the middle and fold it over. I use a heat gun to heat the Kydex. I use a heat gun so that I can direct the heat to a specific location. In this case I only want to heat the Kydex along the fold line.

I don’t need the pattern to do this. All that is necessary is to fold the Kydex so that the left and right edges are flush.

Once folded, I clamp the Kydex to hold what is now the front and back in place until the Kydex cools.

I also don’t need the pattern to form the belt loop as I have a form for that.

I clamp the Kydex to a ¼” piece of wood and heat the front side and insert the gun. I don’t heat the back side; I clamp the holster to the wood to keep that back side flat. This is necessary for this design for the belt loop. I form the belt loop and the holster from a single piece of Kydex so I don’t have to use extra hardware. I do this to keep the cost down and so I can always make a holster even if I didn’t have any rivets or screws on hand.


see figure three


see figure four


see figure five


see figure six

After inserting the gun into the holster I place it in the press. If I have done this correctly I won’t be able to remove the gun from the holster. I then heat the holster at the spot that is usually too tight and remove the gun. Heating at this location (the ejection port) eases the hold on the gun. While the Kydex is still fairly hot I replace the gun and press lightly to reform the Kydex at the ejection port but the fit is not as close but just enough to help hold the gun.

I have to do this occasionally with some knives as well.

If I am not happy with the overall shape I can reheat the Kydex in specific locations until I get the exact fit and shape I desire.

Next I heat the belt loop and fold it over. I use a couple of pieces of wood as forms for this. The form is the same width and thickness as my belt.


see figure seven

Because I glue the tab on the belt loop, the bend at the top of the loop won’t crack like the store bought holster (that I paid $60 for!) did during a match. Gluing the loop down relieves the stress on the top of the loop.

Next I glue a couple of strips of Kydex between the front and back of the holster along the outer edge as a welt.

When the glue has set sufficiently I sand and file about a 1/4” off the edges.

Now I have a holster. It took about two hours to complete.


see figure eight


see figure nine


see figure ten

Store bought holster that broke due to a poor design and poor construction. I fixed it with epoxy glue. Also, my design allows for a 15 degree forward cant that the designers of the store bought holster didn't think of or didn't know how to fabricate (I am always trying to see if I can make or do something better).

see figure eleven


see figure twelve

I use eyelets on the High Standard Derringer holsters and most sheaths.
 

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Looks good. :thumbup:

You have more patience than I do. I just cut an oversized square, form it, fasten, and beat it against the grinder until the shape pleases me. Patterns make my brain hurt. :p
 
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