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fishing line shock cord ?

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jef955

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Just curius if anyone has ever tried using any of the "superline" type fishing line for shock cords ? They seem to be made of either Kevlar or Dyneema which I've heard is the European name for Kevlar. Also, it's very easy to find at any sporting goods store. Thanks in advance for any opinions or info. And yes, first post :)
 

Swampworks

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I have often thought about it but never actually tried it. I can't see why it would not work, especially if it is Kevlar.
 

rocketguy101

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ISTR some threads on the old TRF (or was it RMR?) about this...something about there is a line of fishing thread that IS kevlar with similar/same name as the meltable stuff? You have to read the label...I have never been able to find the kevlar stuff in stores--however I don't get to a Bass Pro Shop very often. If it is 100% Kevlar, it will be OK.

Of course, the old brain could be fooling me!
 

bobkrech

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Dyneema is a registered trademark of Royal DSM (The Netherlands). Honeywell developed a product identical in chemical structure, which is sold under the brand name Spectra.

Dyneema and Spectra are gel spun through a spinneret to form oriented-strand synthetic fibers of UHMWPE, which have yield strengths as high as 2.4 GPa and density as low as 0.97 kg/l (for Dyneema SK75). High strength steels have comparable yield strengths, and low carbon steels have yield strengths much lower (around 0.5 GPa). Since steel has a density approximately equal to 7.8 kg/l, this gives strength/weight ratios for these materials in a range from 10 to 100 times higher than for steel. Strength to weight ratios for Dyneema are about 40% higher than for Aramid.

A problem with these fibers is that they have little stretch, which is also a problem with Kevlar,so they really don't absorb shock very well. Another problem is that they melt at 150 C which is lower than Nylon or Kevlar so the lifetime might be short.

http://en.wikipedia.org/wiki/Ultra_high_molecular_weight_polyethylene

Bob
 

Micromeister

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The only 100% Kevlar Fishing line I've ever run across was Stren braided Fishing lines. During the mid 90's it was widely available mostly for saltwater HEAVY fishing. tho they did have a 30 and 50lb line used for bass'in in heavy cover. The trouble with the stuff was it woreout the eyes on your fishing rods quite badly! Stren dropped it for their line in 99 IIRC. I still have a couple rolls of 70lb I use on LMR's for shockcords..it's great stuff for shockcords. but Alas I haven't seen another roll in either the natural yellow or died green for about the last 5 years.

Spectra (Spider wire) is some AWESOME Stuff for Bass Fishing, 0 Stretch, super strong 12lb test is the diameter of 4lb mono. but and I say BUT! it can't take even a hint of heat! So much so I've used it often as Burn strings on helo's and RG's. Spider Wire would not make good Shocklines, or shockline anchors.

Spider wire is Great for fishing but Crap of Rocketry! Sorry to Nix a great fishing line.
 

jef955

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thanks for all the info guys...guess for the meantime i'll stick with either the old fasion "rubber bands" or the elastic stuff...
 

Micromeister

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Kevlar is a great way to go
thethead exchange on-line has a ton of Kevlar lines to choose from.

another option and something i've been doing on my micro, standard and LRM's has been a Stainless steel fishing leader and the shockline anchor placed around the motor mount. then attach either kevlar or elastic to the leader. some even come with crimped or braided loops and swivels already attached:)

the last pic is a Micro Beading wire Shockcord mount but the larger one install exactly the same way.
Hope this helps.

Beading wire Shockcord MMT-f_5pic page(128dpi)_07-08-06.jpg
 

texas-bill

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ISTR some threads on the old TRF (or was it RMR?) about this...something about there is a line of fishing thread that IS kevlar with similar/same name as the meltable stuff?
I remember it being suggested on rmr, but for use as suspension lines, not shock cords. I went on a hunt for it, and found it at WalMart, but wasn't going to drop $20 on a roll of fishing line. I understand it's OOP now.


Bill

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jef955

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Micromeister I never thought of the wire leader...Have to try that one. God only knows I have enough fishing junk around - thats running me out of the house too !
 

4G's

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I actually have used fishing line for my shock cord...once. I launched a D powered estes rocket. After apogee at about 800-900 feet, the parachute deployed but then I soon realized that it snapped away from the rocket. I used 10 pound monofilament line thinking it would be enough. I used monofilanment because it streches with tension...like a shock cord. Braided line has no stretch, yes it is very strong with pull, but very sensitive to any abrasion...like on ejection. If you put a lot of time and effort, not to mention money, into your rocket; its probably safer and easier to just use a shock cord.
 

Ford Prefect

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I used fishing line once and got a terrible zipper out of it.

Cj
 

DM1975

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another option and something i've been doing on my micro, standard and LRM's has been a Stainless steel fishing leader and the shockline anchor placed around the motor mount. then attach either kevlar or elastic to the leader. some even come with crimped or braided loops and swivels already attached:)
This is what I have been useing for all of my rockets. The fishing leaders that are spliced that I get in my area are coated with a plastic that melts right off and the splice comes apart easy so I burn off the plastic and take the splice out and twist the ends into loops and dab a bit of epoxy on the twist. Have not had one fail me yet, knock on wood.
 

Micromeister

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I used fishing line once and got a terrible zipper out of it.

Cj
CJ:
Believe this or not but all that is needed to remove the possibility of a zipper is a single piece of 1/2" x 3/4" masking tape placed on the line Just where it meets the forward end of the body tube. So easy it's almost absurd LOL!!! Try it, it Works.
 

Swampworks

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Monofilament is very susceptible to heat/flame. I would bet that the line did not "snap" but it burned through.


I actually have used fishing line for my shock cord...once. ......... I used 10 pound monofilament line thinking it would be enough. I used monofilanment because it streches with tension...like a shock cord. Braided line has no stretch, yes it is very strong with pull, but very sensitive to any abrasion...like on ejection. If you put a lot of time and effort, not to mention money, into your rocket; its probably safer and easier to just use a shock cord.
 

bcanino

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Long ago and far away, in another galaxy, I used something called squidding line.
It was very strong. It wasn't easy to get before and I don't know if they still sell it or not. I switch over to Kevlar exclusive.
 

MKP

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Dacron fly line backing. I think it was once refered to as squidding line. I have used it in recovery systems before, but not in a high heat situation simular to kevlar, just heavy duty shroud lines and the like. Look in the fly fishing section of a sporting goods store and it should be there.
 
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