Flying In the Face of...

Wisdom, the facts, popular opinion. You fill in the blank. I was at the store picking up some tackle at lunch today (like I need more) and bought a couple spools of line while the rebate is still in effect (last day). I wanted to try and get some fluorocarbon line in heavier test ratings to play around with, but ended up buying some copolymer line instead. Despite all the rave reviews and the incessant virtues extolled by many, both from the companies and their devout users of fluorocarbon, the data continues to suggest at the very least a big misunderstanding of the line and it's properties, if not some blatant false advertising. I came across the follow-up review of 14 brands of fluorocarbon lines as retested by the Tackle Tour website. I've also had a friend personally test these properties and come to the same conclusions:

1. Fluorocarbon is not low stretch. It stretches as much as regular mono or copolymer lines in most cases.
2. Once stretched, fluorocarbon retains a certain amount of deformity that mono doesn't
3. and finally, regardless of knot tied, you'll be lucky to get 80-90% of the lines actual breaking strength, probably less. 
4. Oops, one more. NO, fluorocarbon is NOT invisible! I have copies of the long and torturous physics calculations to prove it ;)

The article: Tackle Tour's Fluorocarbon Showdown Sequel

Comments

[Paul Roberts]

I'd have to agree, from what I've read. And I never believed any translucent line could be invisible with the opportunity for it to act like a fiber optic cable.

I've thought that the only real advantage of fluoro is it's density and better ability to keep straight(er) line contact with subsurface lures, and some advantage in wind.

Since you have some experience with deeper water fishing, what do you think about this, Brian? The density/sensitivity potential?

[Big Indiana Bass]

I've always tended to believe it was a few factors combined, one of which these tests have now largely disproved, I believe (LOL). That was a belief that while overall stretch was comparable to mono, the force required to start that stretch was different. In other words, like a fresh rubber band. Hard to stretch at first, but once started it always stretches out the same. But tests using weights/strains well below the breaking point of the lines (2,3,4 lbs. in various tests I've seen) and showing equal stretch to mono at those levels refutes that idea nicely. So scratch that one. The one possible saving grace of that theory could be at very small strains (read fishing lure size, typically under 1/2-oz.). It might hold up under those conditions, but I plan to test that one myself to find out for certain.

That really only leaves two possible explanations. One being the "straighter line" theory which I think still holds merit, a more direct connection if you will. Interestingly enough this would be very easy to test at least anecdotally (visually) in a large (olympic size) swimming pool, or on a very clear lake with a diver. Hoping one day someone does this test.

The other factor is more physics related and pertains to elasticity and density. The two are actually tied together in formula when dealing with the speed of sound, which is just vibrations being transmitted through a medium, not unlike what we experience fishing. Here is a link to a website that deals with these properties nicely: http://www.ndt-ed.org/EducationResources/HighSchool/Sound/speedinmaterials.htm

So I'm guessing that given the equivalent diameters of mono and fluoro, the density/specific gravity of fluoro allows for faster transmission of vibrations in combination with a similar if not higher degree of elastic properties that do likewise. I think the answer ultimately lies in the formula provided in the link (V = square of Cij/p).

I did also come across this pretty decent article on fluoros, scratch his superior knot comments. I do like the specific gravity numbers though:
http://www.riversmallies.com/guestart_tdixon1.html