Jed, I use gel spun quite reguarly for backing and it has it’s ups and downs. Dan Blanton’s site has a good deal of information about gel spun and the comments by Aussie legend Max Garth makes interesting reading, this guy has done A LOT of research on the varieties gel spun.
The Aussies seem to do backing pretty well and have the knots sorted, one of the major drawbacks of knotting GSP is the dramatic drop in breaking strain you will experience. One train of thought is to go heavier on the original bs of the line to reduce the reduction caused by knots. Some good information here [url=http://www.flyfishinsalt.com/article.jsp?ID=36721:5ade7]http://www.flyfishinsalt.com/article.jsp?ID=36721[/url:5ade7]
My favourite backing is Bionic Braid, you guessed it an Aussie product [url=http://www.harro.com.au/bionic.htm:5ade7]http://www.harro.com.au/bionic.htm[/url:5ade7] the site has some info about the line and some recommended knots to reduce the reduction in b/s brought about by a number of the usual knots. One US product which seems to come near is Western Fillaments TufLine XP. For both of these I usually start at the 50lb stuff as once you have factored in the knots the breaking strain on the line about matches the limit of the rod. I don’t know about you but I prefer the weakest part of my set up to be in the line rather than the rod.
I’m sure Max will not mind me copying some of his wisdom here.
Basically there are two brands of fibre, Dyneema, made these days by Toyobo Co in Japan and Spectra made by Allied Signal in the USA.
Both these products are made under patent license from DSM HPF in Holland, the inventors of the product.
Spectra is, under the license agreement, braided into fishing lines ONLY in the USA, while Dyneema made by Toyobo supplies the rest of the world.
Or thats my information.
Anyway the braided lines are braided on machines to a variety of formulas depending on the number of carriers, bundles of firbres in the braid, or the number of piks, the weave rate. Braids that a 8x8 are generally considered to be round, whike lesser baids are usually flat.
There are other treatments, Fusion or Fireline are made under a Berkley patent and are not true braids,
Polyethyle cannot be dyed and although the product may be coloured it is not fixed and will reduce eventually to the basic white colour.
Knot strength is low, because of the physical features of the fibre, it is high modulus of elasticity, stiff, has a critical radius and is very slippery.
In knots under stress the fibres slip, and tighten up reaching the critical radius point, fibres break, which decreases the line b/s and the knot fails…The fibre can be cut wiith knives, and sizzors, and the abrasion resistance is directly related to diameter. Lower breaking strains have much lower abrasion resistance than higher brealing strains, and round braids, like 8x9 braids have a higher abrasion resistance than flat braids.
GsP fibre is something like aluminium, because of the stiffnes, modulus it suffers from flexion problems and can fatigue, which effects lines which have knots or loops connecting the line to terminal tackle,
But if you adhere to the rule that nothing is forever, GSP braids make excellent backing lines because of the low diameter for breaking strain, great strenth, low stretch and low ater drag. The best terminations are coaxial spliced lops, which remove knits from the system.
The most advanced GSP braid to use for backing is Bionic Braid made in Australia, is a 8x8 braid made with Micro Dyneema, thinner that other yarns and this gives a 20lb line a B/S of 26lb. 30 a B/S of 42lb and 50 a B/S of 72lb. The reason for this is that the yarns are a much lower denier but the diameter has been kept to the standards of other yarns, like its the same diameter as other lines, so the B/S has increased.
For lighter rods, 20lb can be used in place of 30 and is cheaper, 30 can be used in place of 50lb and is also cheaper, but since its a high standard product it is expensive.
I’m not up on Spectra braids except that I used 120lb PowerPro hollow GsP braid stuffed with 20lb mono as a running line. I also use 20lb Braided mono, Gudebrod stuffed with 20/30/50 BB and have used a commercial trial line of 50lb Platypus GsP braid with a 10lb mono core. All these rinning lines are very good, have no stretch, very low diameter, are coaxially spliced with loops which removes knots and they do not loops or get knotted in use.
I suggest a call to DSM high performance fibres in Herrlen in Holland to get a few brochures on the stuff. You will then know more than the experts in shops.
Cheers mave fun GsP is the way to go, but be careful, it hates oysters and barnacles and being reefed. Cheerrs MaxG
and…
The problem with knots is that some are designed for monofilament and if you use them in other type lines the breaking strain plummets. Like Biminis and GsP braid, it gets not much better than 80% unless you put upwards of 100 twists in the knot, then it only gets a bit above 90%. Micron and Dacron are polyester and are not good vehicles for basic mono knots. With Micron and dacron its better to splice the braid, if you can actually do it, but with care you can splice 30lb
dacron and micron
It is better if you stuff the line right through a 6 inch piece of 20lb braided nylon, like Gudebrod not cortland which is waxed and then splice the lot. Then use Loctite 406 cA glue to secure it. This protects the actual dacron/micron splice from runner strike.
These days its better to use GsP braid as backing, with graphite rods, as the stretch is minimal, as is water drag.
With dacron/micron the abrasion resistance is not high for the b/s and GsP isn’t much better but 50lb GsP is about 1.8 times thinner than 30lb Dacron and Micron and its a lot better for abrasion resistance.
I guess its a matter of choice, but after having been forced to use Dacron/micron for years, like 30 odd, because it was all there was, other than mono, now I wouldn’t touch it in a fit.
What I am really saying is don’t use anything but GsP braid and do not use knots in braided lines. Thats the result of 38 years of SWF experience.
Max
JME
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