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Old 12-25-2017, 12:11 PM
Silver Creek Silver Creek is offline
Join Date: Jan 2015
Location: Wausau, WI
Posts: 88
Here's the best article on Fluorocarbon vs nylon Monofilament.

Tippet shootout

The video contains some incorrect information.

First of all, the difference in specific gravity of fluorocarbon and nylon is not enough to make a difference in sink rates. Both nylon and fluorocarbon leaders and tippers will float because of surface tension. Furthermore, the extrusion process of making nylon and fluorocarbon lines coat the lines with a silicone lubricant that helps both lines float.

Nylon only degrades if heat, light, and ozone reaches the line. So if the line is stored in a cool cabinet in a zip lock bag, it will last for years. Fluorocarbon will last for centuries. There is no need to every replace unused fluorocarbon leaders or tippets.

Nylon monofilament absorbs water. Nylon mono can absorb 10% by weight of water and it loses 20% of its strength. Nylon mono is like spaghetti; it swells, and it gets weaker. Since the mono in knots swell as they absorb water the mono gets pinched and the knots weaken. The only good thing is that limper mono results a longer drag free drift. But the stretch also increases so there will be a slight delay in transmission of a strike. The result of a softer swollen water logged mono is that it is less abrasion resistant.

Fluorocarbon does not absorb water so it it does not lose any strength. What you start with is what you get. That alone makes it a tougher and more consistent leader for nymphing.

If you are using a 5 lb tippet, the nylon will eventually be a 4 lb tippet. The 4 lb nylon is 20% (5-4=1 and1/5 = 20%) weaker than the 5 lb fluorocarbon. The other way to look at it is that the fluorocarbon is 25% (5-4=1 and1/4 = 25%) stronger than the 4 lb nylon. It funny how they both mean the same thing. I prefer to use a product that is 25% stronger than one that is 20% weaker for nymphing.

The same is actually true of most of the knot tests that are published. The knots are tested dry and not wet or after a few hours of soaking. So they are better than nothing but they are not real world tests either.

Yellowstone angler did a water absorption test. Although nylon was stronger in dry knots, when the knots were soaked in water, fluorocarbon won out:

"Since nylon absorbs water and fluorocarbon is supposed to be impervious to it, we conducted a few knot tests with materials that had been soaked for 4-5 hours. We found both the straight-pull break strength and knot strength for nylons did decrease - about 20 percent when wet. We found breaking strengths for fluorocarbon also decreased - however only about 3 to 5 percent when wet."

Modern nylon and fluorocarbon and nylon materials are no longer a single type of nylon or fluorocarbon. Modern fluorocarbons are not the same stiff lines of years ago. The best nylons and fluorocarbon leaders and tippets are now composites that can have a core of stronger hard material and a coating of softer material for better knot holding. It all gets very complicated and the leaders and tippets are getting thinner and stronger with better knot holding ability.

If the nylon is not submerged there is little water absorption. Both nylon and fluorocarbon are equally visible when the are floating so fluorocarbon has no visibility advantage for a floating leaders. So all I need to know is that nylon is cheaper and better for dry flies and fluorocarbon is better for sunken flies and nymphing. If I use a nylon leader with a tippet ring, I can add a nylon or fluorocarbon tippet as needed. Even if the nylon part of the leader absorbs water, it will still be stronger than the fluorocarbon or nylon tippet that is tied to the tippet ring.

As for replacing nylon every year, consider my logic for not doing so. Lets assume the mono loses 20% after a year of fishing. It is 4 lb after one year ( 5 lb - .2(5)). So while I am fishing near the end of the first season, it would be 4 lbs. So you are telling me because it is weaker at 4 lbs at the BEGINNING of season 2, I need to replace it but when it was the SAME 4 lbs at the END of the first season, and it was OK to fish it then?

Do you see that the logic of that makes NO SENSE at all. I take a very practical view. The loss in strength is gradual so the "tipping point" of replacement cannot be at any given set time. Degradation varies with the exposure of the tippet material, how it is cared for during the season, and during the off season. Now I don't know if it loses 10%, 20%, 30%, etc during the first season. What I do know is that whatever the loss, it is the same at the beginning of season 2 as it was at the end of season 1. The key is that I test the strength of the mono at the beginning of the year and during the year. When I think it is too weak for the fish I am fishing for; OR if it breaks too often I throw it away. If it begins to break and the beginning, middle, or end of a season, I get new tippet.

There is an exception and that is when I fish very thin tippets say 7X in locations with large fish, I use new tippet. But for 5X and thicker, these are so much stronger than the tippets of the past that I do not feel a need to swap them out every year. I started fly fishing in the 1970s when the very best tippet was Nylorfi and it was about 2.4 lbs breaking strength. I landed plenty of large fish on the San Juan. If you want a lesson on how strong 5x tippet is, tie your leader to a 4 lb bag of sugar and try to lift it with your rod. but make sure you have a free replacement warranty.


"Discovery consists of seeing what everybody has seen and thinking what nobody has thought"..........Szent-Gyorgy
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