How do I seal Kevlar shock cord edges?

I got a Kevlar shock cord from Apogee Components. The edges aren't sealed in any way so I'm worried they will fray. How can I seal the edges to prevent that? Melting them won't work and I hear epoxy (and CA?) makes the Kevlar brittle.

If by edges you mean ends, I use flexible medical tape.

I've had good results "sealing" the cut ends using Titebond II wood glue. I simply dab the glue on the end of the Kevlar, and work it into the fibers at the tip, making sure not the squeeze all the glue out. Then I form the tip into the shape I want it to cure into, then let it dry. Works great for me.

I use heat shrink tubing around my knots (usually a Duncan knot) and cover the loose end back over the main line.

Example in this post:


https://www.rocketryforum.com/showthread.php?t=130936

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tibbe said:

I hear epoxy (and CA?) makes the Kevlar brittle.

Click to expand...

Yes and no. Yes, it will make the Kevlar brittle, but only where you've applied the glue. The glue will bond & harden the fibers, and, at the point between them being glued (stiff) and unglued (not stiff) is where you'll get your weak point and eventual (possible) failure. if you're tying a knot in the cord, the free end, (the 'tag' end) will never have any stress on it, and so, putting a drop of CA on it won't affect it's overall strength (over the length of the cord).

And, I usually just tie an over-hand or figure-8 knot to stop the cord form fraying / unravelling..

CA glues will run up the Kevlar line and make it brittle.
You could use a small drop of epoxy on the end, that won't fun up the line as far.

I usually use Titebond, smearing a drop around 1/4" at the end.
After it dries the frayed end is hardened and can be cut clean with wire cutters.

Wire cutters will cut better than a hobby knife and you won't end up with a dull knife blade.
Kevlar is used in the place of steel wire in many applications, why not cut it like wire?

I use either shrink tubing or just masking tape. But mostly masking tape. It'll start to wear after ~10 flights, but just wrap it again with some more. It's very heat resistant! I also wrap masking tape around ~2 feet of the kevlar cord that connects closest to your ejection charges - just extra protection for your recovery system.

-brant

A dollop of CA at the very end of the cut end of the Kevlar isn't going to hurt a thing and will keep it from unraveling. Do not, I repeat, do not saturate a knot with CA. Makes the Kevlar brittle. The flexible Titebond or shrink tubing are much better remedies to
hold a know. Kurt