Kydex-Kevlar Sheath

The sheath could be brought to lower temperatures simply by placing it above a very cold source like dry ice or liquid nitrogen, and letting the air gradually cool it down. However the only way to test it with the whole sheath at a constant uniform temperature is to be in that enviroment. Otherwise as soon as the sheath is moved to a warmer enviroment you will get temperature gradients as the outside comes into thermal contact with a large heat reservior. So you would want to be in a large freezer, or in a much colder climate. Or do your tests very quickly after the temperature has been reached so the gradients are small. Kydex is a strong insulator, so heat takes awhile to travel through it. You could measure this by putting a thermometer inside and outside the sheath and watching how fast they equalize if you are curious.

-Cliff
 
Thanks Cliff
I'd not thought of that. You are of course right about testing at a different temperature than the one to which the sheath has normalized. The dual thermometer scenario just might provide some insights on the test window.
-carl
 
I take it you didn't like the concentrated HCl idea??? :p

I understand your concerns. For cool down/ warm up to work best, it would be wise to use a large bath (lots of liquid) and warm slowly, preferably with stirring to even out the temperature. A medium-sized cooler might work.

Like Cliff, I don't like just putting it in dry ice or liquid nitrogen. Too difficult to control, and different parts of the sheath will likely be at different temps.

If you're in for a gadget solution, infrared thermometers exist. They basically scan the surface of an object and tell you the temperature. This would work a lot better than a conventional bulb thermometer, as you could measure the sheath directly. Again, if you heat or cool slowly enough, the kydex should be at a uniform temperature.

Of course, the absolute *best* solution would be to take a vacation in Alaska, and wait for suitable testing weather. :D
 
Concentrated HCL, dry ice, liquid nitrogen...... :(

What am I thinking.....give it hell Carl!!! :D

BTW guys, I'm up for a pass around.

Thanks for everyone's input BTW!!
 
Tohatchi NM
Man! I like the way you think!! Vacation. That is what I need, a "hands on" test.

Andrew-
Already have one taker for the pass-around, but we need written agreements from everyone to promise to return it :D Tis truly a thing of beauty in both form and function.

-carl
 
I sincerely hope everyone understood my comment about a written agreement for the "pass-around" was entirely tongue-in-cheek. My intent was to compliment Andrew's work as being so good as to become coveted ...perhaps a bit over the top.
-carl
 
A passaround! Great! (now all I need is a BM to put in it ;) )

I miscalculated.

Concentrated salt water might be able to get down to -10 or -15 F
Will be doing some experiments to see exactly how cold and I'll post the results.
 
Tohatchi NM-
We already have results of -20F. What we lack is reliable ways to test below that temperature, and in controlled gradients of, say 10 degrees F. We think we are very close to the lower temperature threshold. So. If we were able to go directly to -60 degrees F and got failure, that would raise the question: where between -20 and -60 did we cross the line? That is our current issue.
-carl
 
Originally posted by Andrew Lynch
Concentrated HCL, dry ice, liquid nitrogen...... :(

What am I thinking.....give it hell Carl!!! :D
Click to expand...

I wonder if the sheath is bullet proof. At least to small arms.????
 
That was not our intent and is unlikely to be the subject of any test. Interesting question, though...:D
-carl
 
If you really wanted to do some sort of testing at lower temperatures, give me a shout. I use a chest freezer where I work to keep certain mixed polyurathanes from curing to early. I keep it at -58 degrees. That is as low as I can get it to go. It does adjust in increments though. Just a thought, as I love the concept of this sheath. Any help that I could lend would be fun and who knows, maybe I could get on the list for one if you ever make any to sell.;) Good luck guys! A nice tough idea!:cool: :D
 
Andrew-
I've grown so fond of this sheath- still shining after what it has been through- that I am unlikely to shoot at it. We may need to invoke Cliff for that test.:D
-carl
 
Originally posted by ArchAngel
If you really wanted to do some sort of testing at lower temperatures, give me a shout. I use a chest freezer where I work to keep certain mixed polyurathanes from curing to early. I keep it at -58 degrees. That is as low as I can get it to go. It does adjust in increments though. Just a thought, as I love the concept of this sheath. Any help that I could lend would be fun and who knows, maybe I could get on the list for one if you ever make any to sell.;) Good luck guys! A nice tough idea!:cool: :D
Click to expand...

I am interested if these temps are degrees F. I'd really like two tests- one at -30 and one at -40 where the sheath had time to "normalize" at the -30 temperature and the test was conducted then at the -40 temperature and the same test conducted.

The test(s) are: Insert / remove knife, drop with knife in sheath-point down- from 6 feet, drop again from 25 feet- all onto concrete. Tests are progressive- run in order. All CC's should be tight (read: firmly tightened, not torqued) before test is run. If the sheath cracks, record the test that caused the crack, but continue testing as long as sheath integrity remains. By "integrity" I mean if the sheath would still function as a sheath, keeping sharp edges enclosed.
-carl
 
I've made three more of these sheaths (or similar in style). I think I've got all the manufacturing quirks worked out.

If you're interested in one, shoot me an email and we'll talk. I warn you though, once you get used to this stuff, everthing else will seem flimsy :D

For you guys going to Blade, I will have several examples of this type of sheath as well as others to check out. Some of them are even for show more than go :eek:
 
Still being tested. That said, I would contact the maker- Andrew Lynch- to see what he wants to do about making more. FWIW- This is many times tougher than any Kydex I've handled. I would own one in a heartbeat. Evolute will be getting this one to evaluate soon.
-carl
 
Every time Andrew shows me the latest sheath he's made, my jaw drops. The last Kydex/Kevlar thingy I held that he made was really nifty, and the one he was telling me about today . . . well, it was bloody astonishing. He won't let me see that one, though.

Of course, I'm not gonna give any specifics, because that's his job. But all of it is amazing. :)
 
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