Effect of Water on Fly Line Buoyancy

t1mmmy

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Hi,
I am a fourth-year Mechanical Engineering student and for my masters' project, I am investigating the effect that water has on a fly line's ability to retain its buoyancy after a long period of use.
Initial research and thought for the potential tests have been to test damaged floating and intermediate braided multifilament lines and keep them submerged for a prolonged period of time (say around a month) to mimic normal use of a fly line.
As a keen spin fisher but relatively new to the world of fly fishing I thought I'd ask on here if anyone could offer some insight on the tendencies of lines to float/sink after prolonged usage, or have experience they'd be willing to share about this topic.
Many thanks
Tim
 

icejohn

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When i did a lot of fly fishing, with older school braied cores lines they would turn into a sink tip noticeably. But two weeks of none use they would dry out again. I put varnish on the end to seal the fly line in the end.

Not had any issues with cracks in the mid part of the fly line.
 
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Tangled

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Well good luck!

Some random thoughts

1. You need to be aware that floating lines can be made of PVC or PU (Polyurethane). There may be differences. (Airflo lines are the only company I'm aware of that makes PU lines.)
2. As said above, fly lines don't spend weeks under water!
3. A fly line's buoyancy depends on added microbeeds in the plastic. Thin fly lines can hold fewer of them, this is one reason why the thin ends of fly lines often sink
4. Another reason is that the tip is often not properly sealed - particularly if the line has no loop or it's cut off.
5. It's a very narrow and niche topic, I doubt you'll have much to look at in a literature review - but maybe that's a positive ;-)
6. it would be worth contacting Mike Barrio at Barrio lines. He's here in the UK and might be interested in your work. He might also give you a few lines...

Keep in touch
 

icejohn

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Would say the end is the main issues sealed or un sealed...


Some manufacturers have a single mono core. This sucks up water like a damm straw - capillary action.

The braided cores or multi stand still sick up water but they dry out quicker (2weeks) where as mono core is like a month to dry out.
 
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original cormorant

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Would say the end is the main issues sealed or un sealed...


Some manufacturers jsve a single mono core. This sucks up water like a damm straw capillary action.

The braided cores or multi stand still sick up water but they dry out quicker (2weeks) where as mono core is like a month to dry out.
That seems counter-intuitive surely it's braid that has a capillary action, whereas there's no space in a monocore and consequently no scope for capillary action.
 

icejohn

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Well had an old airflow mono core and it sucked up water fairly easily but took ages to dry out.
 

t1mmmy

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Hi
Thank you for your replies.
I am also in the process of trying to acquire some floating or intermediate fly line that is no longer useable due to it being damaged. Do any of you have any old line lying about that you would be happy to send over to me? It would make my experiments more genuine to use a line that has seen real fishing action!
happy to pay postage etc
 

running bear

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I agree with most of the replies above.

Damaged lines sink quite quickly, the 1 month simulation will result in n=0 floating, sealing the ends may assist that, but damaged lines just don't float once ingress hits a certain point, nor as posters have stated, is it likely to simulate fly fishing situations.

Purely from a fly fishers perspective, a much more useful/meaningful investigation would define how long damaged fly lines float, by the amount of damage (maybe measurable by cracked parts per length)?

Still a complex experiment, when you consider some upward force from the static (above water) rod tip and the varying lengths of line from that static rod tip. Then there's forces from flows (rivers), undercurrents in still waters caused by winds etc. Additionally, location of damage in relation to non damaged sections would probably have a impact, e.g. 10 cracks of x total magnitude per metre may be fine for 2 hours, but not if they are all in the first 10cm of that metre.

Alternatively, you could measure water takeup over time (using mass) and then assess this versus the forces acting on the line as it floats, including the wet line density, upward forces from rod tip etc

I wish you luck, but as a numbers guy, I see a very complex model very quickly, although it wouldn't be Masters level if it were easy!
 

dgp

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I agree with most of the replies above.

Damaged lines sink quite quickly, the 1 month simulation will result in n=0 floating, sealing the ends may assist that, but damaged lines just don't float once ingress hits a certain point, nor as posters have stated, is it likely to simulate fly fishing situations.

Purely from a fly fishers perspective, a much more useful/meaningful investigation would define how long damaged fly lines float, by the amount of damage (maybe measurable by cracked parts per length)?

Still a complex experiment, when you consider some upward force from the static (above water) rod tip and the varying lengths of line from that static rod tip. Then there's forces from flows (rivers), undercurrents in still waters caused by winds etc. Additionally, location of damage in relation to non damaged sections would probably have a impact, e.g. 10 cracks of x total magnitude per metre may be fine for 2 hours, but not if they are all in the first 10cm of that metre.

Alternatively, you could measure water takeup over time (using mass) and then assess this versus the forces acting on the line as it floats, including the wet line density, upward forces from rod tip etc

I wish you luck, but as a numbers guy, I see a very complex model very quickly, although it wouldn't be Masters level if it were easy!
All very academic but the results would not have much practical value especially as it is easier to bin the line and buy a new one for a few pounds.
 

James9118

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Hi,
I am a fourth-year Mechanical Engineering student and for my masters' project, I am investigating the effect that water has on a fly line's ability to retain its buoyancy after a long period of use.
Initial research and thought for the potential tests have been to test damaged floating and intermediate braided multifilament lines and keep them submerged for a prolonged period of time (say around a month) to mimic normal use of a fly line.
As a keen spin fisher but relatively new to the world of fly fishing I thought I'd ask on here if anyone could offer some insight on the tendencies of lines to float/sink after prolonged usage, or have experience they'd be willing to share about this topic.
Many thanks
Tim
Hi Tim,

Can I ask about the bigger project - are you working on anything interesting like self-healing polymers?

Cheers, James
 

Whinging pom

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Hi
Thank you for your replies.
I am also in the process of trying to acquire some floating or intermediate fly line that is no longer useable due to it being damaged. Do any of you have any old line lying about that you would be happy to send over to me? It would make my experiments more genuine to use a line that has seen real fishing action!
happy to pay postage etc
Ive just taken off a old Wulff TT floater thats old and worn happy to donate it to science:)
send me the address and don't worry about postage
all best and good luck with project
the pom
 

diawl bach

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May 17, 2006
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9,170
Hi,
I am a fourth-year Mechanical Engineering student and for my masters' project, I am investigating the effect that water has on a fly line's ability to retain its buoyancy after a long period of use.
Initial research and thought for the potential tests have been to test damaged floating and intermediate braided multifilament lines and keep them submerged for a prolonged period of time (say around a month) to mimic normal use of a fly line.
As a keen spin fisher but relatively new to the world of fly fishing I thought I'd ask on here if anyone could offer some insight on the tendencies of lines to float/sink after prolonged usage, or have experience they'd be willing to share about this topic.
Many thanks
Tim
Hi Tim I'm just about to change a floating fly line which has begun to sink, send me your address and I'll post it on. Its three years old but as the lockdown curtailed my fishing it's only seen two years use.

You'll see the portion of the line I've cast the most regularly has cracks right along the length of it, presumably the cause of its loss of buoyancy. I'm changing the line because the cracks create friction as the line passes through the rod rings, it reduces the length one is able to cast and upsets the feel which a smooth line has when retrieved so it's time for it to go.

Like many other fly fishermen I use a product called Mucilin to counteract the tendency of the tip of the fly line to sink, you apply it with a cloth, have a cuppa then polish it with a dry cloth, this helps the line pass through the rod rings more effectively and increases its buoyancy - looks like the main constituent of the product is petroleum jelly. Increased cracking results in increasing the application of Mucilin, you can only drink so much tea.


The buoyancy is important as it prevents the tippet from being dragged under by the line which enables the line to be lifted from the water more easily and preventing disturbance to the water which results from lifting a submerged fly line to re-cast it.

If your studies lead to the discovery of a treatment which prevents a line from cracking patent it, you'll make a fair few bob.
Good luck with your venture, hope you receive enough old line to further your work.
 

t1mmmy

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Hi Tim,

Can I ask about the bigger project - are you working on anything interesting like self-healing polymers?

Cheers, James
Hi
The project is very much in its initial phase. I'm just trying to find out where to focus my attention on experiments/research to produce the most meaningful results.
Ill definitely have a look into self-healing polymers
Cheers
 

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