Shock Cords

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Kevlar in the body tube to either tubular nylon or a smaller diameter kevlar cord or flat kevlar out to the chute and nosecone.

Usually there’s a swivel in the mix as well.
 
I will do this too, I learned how to sew a straight line with an old Singer machine, I will use kevlar thread, I also like the idea of sewing a loop in the tubular nylon instead of a knot, makes a lot of sense!
 
Caveat Emptor

Three years ago I bought a LOT of Nomex from online vendors on Amazon and Ebay to make cord protectors and burrito wraps. I bet I have 16-18 yards of stuff in my upstairs 'project bin'........only two pieces turned out to be suitable for rocketry, and I'm given to believe that half of the rest of what I bought probably isn't what it was advertised to be at all.

Of all the pieces of cloth that I did buy, only 2 were as heavy as the popular 'orange' nomex blankets (NO, I don't know what the spec is) sold by rocket vendors. Those are the ONLY two pieces that have endured......and I was never able to buy more of that cloth again. The good news is that a yard or two of the correct cloth is a near lifetime supply.....sorta like a bale of dog barf.

Some of the more prevalent issues that I encountered(that do not happen with the commercial units):
NOT flame resistant (at least two pieces of 'Fire Proof Nomex with Kevlar weave' actually caught fire on ejection!)
Open knit-type weave allowed burning BP particles through
No matter how the edges were sewn, would NOT hold thread
Z.E.R.O. blast resistance
Not abrasion resistant/durable

SOME of those issues can be mitigated somewhat by supplementing with the use of dog barf. But that's using barf as a solution to a problem that you shouldn't have.

If you buy some and it's not as heavy or as tight weave as the commercially available orange ones.......you're not going to get the performance out of it that you think that you are. Been there, done that, still handing out Tshirts.
 
I just tested the stuff I have with a blow torch. A couple seconds of direct flame. Didn't burn. Looks like I got the real thing.

Good deal. Now take a scrap and put it loosely on top of a BP ejection charge and like the charge off to make sure you don't get any blow through.

Lots of "fire resistent" done in a knit weave that blow through easily.
 
I just tested the stuff I have with a blow torch. A couple seconds of direct flame. Didn't burn. Looks like I got the real thing.
I'm intrested in any additional testing/experience you have with this. Like Banzai, I bought some Nomex off of Ebay and have been underwhelmed by its performance - while it is flame proof, it seems nowhere neear as durable as the blankets sold by rocket vendors, and is permeable to ejection charges. I'm like to find a better source.
 
I put some 4f black powder in a pvc cap with an ignitor. No blow thru but it charred the side that was exposed to the flame. It also got brittle. The nomex was doubled. The second piece looks ok. So I probably don't have the good stuff. I used about 1/4 teaspoon of BP. Now I have to air out the garage.
 
Thanks for the update! I would suggest repeating the test with a small scrap of nylon - or one of your chutes, if you dare risk it - wrapped up in the nomex, and inspect for pinholes/burns afterward.
 
Ok. Different result. The first time the BP was loose in the cap. This time I confined the BP in some tape. I thought that confined would be closer to an actual ejection charge. All it did wad discolor the nomex. Which is Aramid nomex. So as a shock cord protector I think I'm good. I'll check them after each launch to see how durable they are.
 
No blow thru but it charred the side that was exposed to the flame. It also got brittle. The nomex was doubled. The second piece looks ok.

The Nomex I used was from flight suits and it did the same thing. Ive since stopped using it for taking a ejection directly and just protecting the chute.
For handling the ejection I have some Kevlar fabric.
 
The Nomex I used was from flight suits and it did the same thing. Ive since stopped using it for taking a ejection directly and just protecting the chute.
For handling the ejection I have some Kevlar fabric.

Flight suit material is amongst the worst ejection protection that I've ever used.
 
The Nomex I used was from flight suits and it did the same thing. Ive since stopped using it for taking a ejection directly and just protecting the chute.
For handling the ejection I have some Kevlar fabric.

How old were the flight suits?

The flight suits I wear all have an expiration date and even that assumes they were washed and dried in a particular manner with proper detergent and no other additives like fabric softener. I can't imagine any fabric cut off an old one having any fire resistant properties left.
 
It was a unworn one that I had laying around and too small for me to wear

That shouldn't be damaged then. Maybe the Nomex is just too thin to be effective? I have 3 suits and 1 from Gibson and Barnes is a lot thicker than the others. It is awful in the Summer. The others are old enough they probably aren't as effective and 1 can let light through.
 
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