Cheap Kevlar thread.

[te_groen31]

Sometimes, it's nice to have a lucky day.

I always ( or better...only ) make scratch-build rockets. So I need
all sorts of stuff.
Kevlar thread is a good example. An expensive one. There's a shop in town,
here, where they sell all sorts of materials for kites.
I buy my parachute materials there. Those new foils are great. Super thin,
super strong and super light. Some sort of synthetic fabric although I
couldn't tell you exactly what it is.
(I shall send Mike O'Malley a sample, soon, so he can examine it for you and print a report ).
I tried several types of thread for my chutes but they either break
or burn away, after 3 or 4 launches............
PHhffeeeww those ejection gasses are REALLY hot. Literally !

The solution ? Kevlar thread. I bought 6 meters from an English
website. Fairly expensive, but so far, that Kevlar thread still has
NOT broken yet.

In that kite shop they still had some thread left over on a small
cardboard spool. I could have it for just 12 dollars.
Sounds expensive, but it is FAR less than half price I saw anywhere else
on the net. It's about 82 feet of thread, by the way.
( just cheacked again: I got it for one third of the price).

So....go shopping and test your luck ! It worked for me.
Sometimes, you find JUST what you need, in a place where you
LEAST expect it.
Although....a kite shop.... not a real surprise to find it there, but still... ;-)

Erik.

 

[Micromeister]

I've been using Kevlar thread for several years for all my Chutes and streamers. the stuff is Great! very very thin, strong and light weight, I believe it's 12lb test material? anyway i've been using it on plastic and mylar competition and sport flying chutes in the 3" to 48" range. and used to sew my rip-stop nylon chutes 12" to 36". It also make great Streamer attachment lines
I've purchased spools of the stuff on-line for Edmonds Scientific off and on. I seam to recall the 600yard spools are about 20.00 bucks

 

[jj94]

Hey, Micro, where can I get some high quality braided kevlar? I've tried the twisted type of kevlar but didn't really like it.

 

[Stymye]

Pratt hobbies
https://www.pratthobbies.com/products.asp?cat=1

 

[2muchstuff]

Originally posted by jj94
Hey, Micro, where can I get some high quality braided kevlar? I've tried the twisted type of kevlar but didn't really like it.

You're right about the thread vs. braided. Stay away from the thread. It can untwist and as a result get snagged or become much more susceptible to damage from ejection charges, abrasion, etc.

I've had a number of rockets that used Kevlar thread suffer from separations, but I've never had any problems with the braided kind.

Just my experience,


tms

 

[jj94]

Originally posted by stymye
Pratt hobbies
https://www.pratthobbies.com/products.asp?cat=1

Thanks. Their kevlar looks nice. Are there any other vendors that sell good kevlar?

 

[Micromeister]

Pratt Hobbies is one source for braided Kevlar, but Pratt is an end user just like us. Years ago I bough a very large amount of several braided lines direct from Dupont. and found a couple other great sources in the commerical fishing line industry. A bit cryptic but due to agreements there are some things even I can't share
while Braided is always preferred over twisted, it's also much harder to locate and usually at a primium price. The Thread Exchange can be a source for some braided kevlar but you MUST read carefully to determine the threads layup.

Cheap Kevlar, was the buzz word in this thread, if you want cheap... don't look for Braided line it's usually 10 to 25% more depending on the size.

That said, I've used a awful lot of both and never had an unexpected failure with either layup. Braided is alway a lot more flexible because it's made up using more smaller strands, but twisted can be worked a little before installation to soften it's coiling without damaging the strand structure or hurting the fibres.
Combine a little pretreatment, proper knots and anchor attachment practices, either will outlast the model in which it is installed.
Hope this helps.

 

[maricopasem]

I know that you can buy the Kevlar thread on the Internet, but I'm not much of an Internet purchaser. Are there any retailers out there from whom you could purchase the stuff?

 

[Micromeister]

Marico:
I'd have to guess finding LOCAL Kevlar will depend alot on Where your located.
I'd try Kite shops, Large fishing tackle shops, and large fabric dealers. All or some of these folks "should" have access to sources that can supply Kevlar theards and braided lines. At one time Kite flyers were using braided Kevlar but all the major distributors have now switched back to Nylon which as considerably more Stretch (good for kite flyers bad for us). Stern had a GREAT kevlar braided fishing line but that also has been discontinued.. You may still fine some of this on the shelves in better tackle shops in Green color.
Hope that helps a bit, unfortunately your best bet is really on-Line purchase, Just be very careful in reading the discriptions of what your purchasing

 

[jflis]

FlisKits has #90 (SLK-90-288) and #150 (SLK-150-288) in 24 foot bundles.

The stuff you purchased worked out to about 14 cents/foot (i don't know the size it was though)

Our #90 works out to 13 cents/foot and the #150 at about 21 cents per foot...

fwiw
jim

 

[PopRocket]

Jim, those prices sound pretty good. What is the width of the two varieties of Kevlar cord that you sell?

 

[jflis]

When I get home I will measure them and let you know.

jim