Fold over Kydex sheaths

[CUTS LIKE A KRIS]

I recently began playing around with making one piece kydex sheaths that do not require glue or rivets. I formed them like normal, but with an extra tab along one side; then "carefully" reheated the tab and folded it over. After a week and a half I have had no problems with the two sheaths seen below. Does anybody else do this? What kind of problems do you see associated with it? (other than my poor sheathmaking abilities)

 

[axeldoomeyer]

Since kydex is a thermo plastic in theary it should hold its shape; however, even sheaths that I have molded to a knife and riveted will get a little loose in time. At least the retention abilities of the sheath. I have never had one come apart... Logic dictates to me that this sheath will hold up as well as a sheath that has been riveted. As a matter of fact I saw a website at one time that the maker uses no rivets what so ever and it is just a series of folds. Keep in mind that Kydex will hold its shape as long as it is not exposed to heat and you might notice the knife retention loosen in time. But this is nothing a 5 minute appointment with a heat gun cant fix. Good luck to you.

 

[RokJok]

C.L.A.K. thank you for reporting your lack of problems so far with that sheath. I like the "no fasteners" idea for kydex sheaths. Much sleeker than the pancake sheaths with eyelets or rivets on both spine and edge sides of the sheath.

To further secure the folded-over flap of kydex, you might want to weld it in place chemically with tetrahydrofuran (known as THF for short, see below).

WARNING!! Tetrahydrofuran in incredibly nasty stuff to work with/around. Be sure to read the Material Safety Data Sheet (MSDS) on it before you use it. You can find the MSDS for THF online. Apply it to your kydex outdoors if you can (for vapor dissapation) and don't have it cure in your house if it is avoidable (like put it in garage/shed).

info below cut 'n pasted from an old posting of mine

Tech support at Kleerdex, the manufacturer of kydex, recommends using tetrahydrofuran (THF) to "weld" kydex pieces together. THF is a PVC solvent of some sort. Cure time will depend on amount of THF applied, amount of moisture in the air, and temperature at which it cures. At house room temps, the engineer said to give it about 24 hours, so this is not a real quick curing solvent.

According to the guy at a local plumbing supply house, there's THF (plus methyl-ethyl-ketone aka MEK) in a multi-purpose plastics cement made by IPS. That might work for chemical kydex welding. Other such plastic pipe welding cements/adhesives may also have THF in them.... check the label listing of active ingredients to see which ones do.

 

[CUTS LIKE A KRIS]

RokJok- thanks for the info on THF. I might consider using it if I move and get a shop outside of the house but that is not an option for now, and may not need it unless I find problems with the sheaths made now- I'll update if I find problems.

 

[Phydeaux]

I just tried something that worked pretty well. Instead of using rivets to hold the open edge of my fold over sheath, I laced it with para cord.

I drilled 1/8" holes about 3/16" apart. I removed the core from the paracord before using. I'll try to figure out how to post a pic soon.

Ric