Can't Get Kydex to "Click."

redsquid2

Bastard Son Of Antiochus IV
Knifemaker / Craftsman / Service Provider
Joined
Aug 31, 2011
Messages
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This is the second kydex sheath I have made for this thing. I swear I have spent almost three hours tweaking with a kydex, to come up with something that will make a solid "click."

I put my oven at 265, and preheat, put the kydex in there for 6 - 8 minutes. I take the kydex out of the oven, I put the knife in between the two layers of kydex, sandwich all of that between two layers of sheath foam, and then I put a piece of 3/4" plywood on top of everything, and I stand on top of the whole enchilada, and I bounce up and down.

Oven not hot enough? Need to leave kydex in there longer? Need to press this in a c-clamp or a vise maybe?

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I heat Kydex to 300 degrees. I'm not sure if your clamping method is going to get the results your looking for. You really need to get the pressure on and then leave it sit until the kydex has cooled enough to retain it's shape. If pressure comes off even at 200 degrees it will relax a little and not go back where you want it.
 
Did you try tweaking it with a heat gun where you want the "click"? I've done that with holsters. Just heat up the spot and then shape with your fingers (gloved fingers) and hit with cold water.

With a heat gun be careful not to scorch it. Maybe play around with some scraps first if you've got.
 
I heat Kydex to 300 degrees. I'm not sure if your clamping method is going to get the results your looking for. You really need to get the pressure on and then leave it sit until the kydex has cooled enough to retain it's shape. If pressure comes off even at 200 degrees it will relax a little and not go back where you want it.

Very interesting. I have been leaving it in my "kydex press" for only a minute or so. I think I will clamp it, and leave it clamped for 10 minutes.
 
Definitely longer. I sometimes leave it for about 20 mins. Clamped tight as well. I don't think standing on it will get as good results as clamping.
I usually heat to 200 then put the kydex in so it doesn't shock and slowly raise temp to 315 or so. I also lay my foam on top of the toaster oven to preheat it.
 
I stand on my kydex, but I stand for about 20 minutes while I catch up emails on my iPad. I don't think bouncing is a good idea.
 
Did some research and followed you guy's tips too. It's better now. I put the kydex in the oven starting at 170 and gradually raised the temperature to 290 while at the same warming the knife and foam with a heat gun. Then I clamped it, and left it clamped for 45 minutes. I could still feel a little bit of warmth when I took it out of the press.

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Clamped it tight.

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It has a much better click now, but you have to carefully guide it in by sight. Otherwise it goes in wrong.

Regarding those aluminum screws, I think they need a soft washer to tighten down. I am using nylon washers, but they don't work so good. Neoprene washers would probably work better.
 
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You can flare the entry with your heat gun and using the back of a sharpie, bend it back.
Or any type of small pipe/tubing. As long as you keep retention tight around where the choil/finger groove is, you'll still have a click.
 
Another tip about going in "wrong." I'm assuming by looking at how it formed that you didn't pad the blade at all with tape or plastic wrap. So the sheath formed a perfect wedge that follows the edge, a funnel really that can encourage the knife to try and stick itself where it doesn't belong on the edge.

Padding the blade a little with masking tape or plastic wrap will help alleviate that and help prevent the sheath from scratching the blade in use, by creating clearance in the formed shell.
 
I'm with him ^^^^^
You need to give the blade a little wiggle room. A strip of masking tape on each side and trimmed to the profile of the blade is what I do. It also helps prevent the kydex from scratching the blade.
 
I don't get enough clearance with one piece per side. I was taught to do at least two layers of masking tape per side and since I started doing that my sheaths improved a lot. No scratches either, (I clean them thoroughly before I put a blade back in there.)
 
We went to three layers of blue tape recently with good results. The trick is really the knife should be held by the bolster area, not the blade..We made a press that uses ratchet clamps on the front but also has two all threaded bolts in the rear with large homemade wing nuts that way even pressure front to back can be applied. We bought the foam made for presses and also eyelet dies and a small arbor press to use them in.. We figured out fast that is you want your kydex to look professional then you need good tools to work it with..
A side note we don't use a oven now. We use a griddle/hot plate set @ 300°. I like it better
 
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That's a great design. I use the same clamps on the front and i tighten them down so much that it's uneven. I tried a hot plate/griddle but it wasn't a very good one. I had uneven temps and ended up scorching the kydex. On the plus side, it made the kydex smell like bacon! JK
Maybe i'll try it again with a newer griddle.
 
I feel your frustration. I adjusted the retention on my xdm kydex holster one time so it would hold better while running/scrambling, and that oh so satisfying click is now gone forever no matter how I readjust it. :grumpy:
 
I feel your frustration. I adjusted the retention on my xdm kydex holster one time so it would hold better while running/scrambling, and that oh so satisfying click is now gone forever no matter how I readjust it. :grumpy:

Nah, you just have to heat and pinch around where it retains. It'll come back.
 
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