What is fluorocarbon fishing line and how to use it

Fluorocarbon is a more recent additional when it comes to fishing line choice, although it has still been available for a long time, and has also improved a lot over the years, making it a popular product with carp anglers.

Many people think of fluorocarbon in terms of it being a hook link material – such as the Korda IQ2 or the stiff Boom material – or something that is used for leaders, and that is the case for many types of fishing, such as with lures, and is what many fluorocarbons were developed for.

Amongst carp anglers though – as well as some specimen anglers – it has also become a popular choice of main line in some situations, and with fluorocarbon lines now available specifically for this purpose, such as Korda Kontour, due to the properties of this material and the benefits it can offer.

What is fluorocarbon?

Fluorocarbon line is almost identical to nylon monofilaments, in terms of how it is produced, but the finished product has very different properties – some of which make it better than nylon in certain situations, but it also has negatives as well, so isn’t ‘better’ than nylon, per se.

The process used to produce fluorocarbon line is pretty much exactly the same as that used for manufacturing nylon lines, with the only difference being the what the pellets are made of that are then melted down. In the case of fluorocarbon, these pellets are made from polyvinylidene fluoride, rather than nylon.

These PVDF pellets are then melted down and extruded through a machine, in the same way as nylon, before being cooled and stretched to achieve the finished diameter or breaking strain of the single (monofilament) strand of fluorocarbon line that is produced.

By varying the exact make up of the PVDF pellets, fluorocarbons can be produced that have slightly different properties to each other – you will find some that are softer or more supple, such as IQ2, or have been specifically designed to be incredibly stiff, such as Boom, even though both undergo the same process and use the same basic material, much like you get with different nylon lines.

What are the advantages of using fluorocarbon fishing line versus monofilament line?

Using a fluorocarbon main line can give you a lot of advantages in certain situations and help you to catch more carp.

One of the biggest attractions with fluorocarbon lines is that it is far less visible in water than a standard nylon line is – the refractive index of fluorocarbon is usually around 1.42, versus somewhere above 1.53 for nylon, and compared to water at 1.33 (depending on factors such as clarity and suspended particles etc).

In simple terms, having a refractive index that is closer to water means that when light hits the line it doesn’t bend as much, and in turn that leads to less of it being reflected – in theory a material with the same refractive index as water will give zero reflection as the light passes through it in the same way as it does the water around it.

Being less visible and obvious to the carp is of course a big advantage, not only when it comes to hook links and leaders which your hook bait is attached to or close to, but also in the case of your main line and alerting the fish to your presence.

Being invisible though is all very well and good, but it won’t prevent the carp from bumping into your line and potentially spooking even more, if they’ve just encountered something that they can’t see.

This brings us on to the other major advantage of fluorocarbon, and that is how well it sinks compared to standard nylon monofilaments, and especially so when fished slack or semi-slack. So not only will the fish be unable to see it, but they are also unlikely to accidentally bump into it and spook, if it is pinned to the lakebed.

Fluorocarbons in general also tend to be quite tough and have high abrasion resistance compared to nylon, plus have very little stretch, which aids bite indication, even with a slack line, and gives plenty of feel when checking for a drop when you cast your rig out.

So the key advantages are that it is almost invisible underwater and hard for wary fish to spot so they aren't so easily spooked, even in clear water; has low stretch - less stretch than nylon monofilament; sinks incredibly well; and is highly abrasion resistant.

Are there any disadvantages of using fluorocarbon as a main line?

Like with any type of fishing line, there are also some disadvantages to fluorocarbon as well – no type of line is perfect for all carp fishing, where such a wide range of different properties can be needed for particular angling situations.

One of the biggest disadvantages of fluorocarbon is the limitations on how far you can cast with it, even in the hands of someone who is very good at casting, you aren’t generally going to be fishing at over 100 yards with it.

This is because it is not only heavier than nylon, and hence why it sinks so well, but it is also a lot stiffer for its diameter as well, and the two of those combined will of course limit casting distance – the stiffer and heavier the fluorocarbon, the worse it will cast.

Kontour has been designed so that it still gives all the benefits that you expect from a fluorocarbon line, but at the same time making it as user-friendly as we can when it comes to things like casting, or even just wrapping up around your distance sticks as very stiff fluorocarbon, with its associated high memory, can turn this into a nightmare if the line starts springing off everywhere or catching.

Some might argue that the lack of stretch, which is more akin to what you’d expect from braid, is also a disadvantage in terms of how much cushioning the line provides during the fight. But in reality, you will soon get used to that, as anglers who use braid do, and this property of fluorocarbon offers far more advantages than disadvantages.

Knot strength is another thing that anglers often highlight with fluorocarbon, failures at the knot are typically down to using the wrong type of knot for this material, or not tying it properly, rather than a reflection of the knot strength that can be achieved with a bit of care.

You could also point out that once fluorocarbon lines gets dirty, via things such as algae or suspended particles in the water, then it loses it ‘invisibility’ as the refractive index of it is altered by the addition of those particles on its exterior. It doesn’t actually collect any more particles etc though than a nylon line would do, and can easily be cleaned to remove that and restore its refractive index back to its normal level.

How should I use fluorocarbon line?

When it comes to using fluorocarbon main line it isn’t really any different to any other type of line.

Just make sure that when you spool it up, you do so by winding it onto your reel under tension and with the spool of Kontour fluorocarbon in water – a Compac Spooling Bucket is ideal for this as it keeps the line wat and provides tension, although you can wind it on even tighter through a towel or similar.

It is also essential that you don’t add any extra twist to this type of line, which typically already has a fairly high memory and can be quite coily when it first comes off of the spool.

Using the spooling bucket helps a lot with this as well, and once you’ve spooled your reel up, you can also tie the end of your line to something, then walk it out and give it a bit of a stretch to help, which will help straighten it and make it more user-friendly when casting, or in situations where you have slack in the line and it could otherwise spring off everywhere. 

It is important as well that you clean your fluorocarbon main line, as whilst the material that it is made from is almost invisible in water, anything that is in the water, such as silt or algae particles, and becomes stuck to the line certainly isn’t invisible.

The easiest way to ensure that your line stays clean, and as invisible as possible, is to wind it back through a damp cloth or sponge whenever you wrap your rods up to recast – something you will see Danny Fairbrass doing all the time.

One of the biggest benefits of fluorocarbon is how well it sinks, but to get the benefit of that you will need to let your line settle and sink after casting out. The best way to do this is once you’ve cast and initially tightened your line, so it is pointing at your rig, then pay off a bit of slack and leave your rod on the rests for a few minutes, before clipping on your bobbins. This will ensure that not only has the line sunk, but it has done so in a direct line to your rig.

You can fish it completely slack, but for better bite indication, semi-slack is best, where any movement on the line still gives an indication by moving your bobbin. Fishing bow string tight lines with heavy bobbins when using a fluorocarbon line pretty much defeats the object of using it in the first place, and if you need to fish like that then you may as well just use a standard mono line.

When used properly, fluorocarbon main lines can be a big edge in some fishing situations and help you to catch more.

Can use fluorocarbon as a leader material?

An alternative to using a fluorocarbon main line is to use it as a leader instead, which utilises all of its benefits close to your rig, but without the potential pitfalls of spooling up your reels with it.

There may well be situations where using a nylon or a braided line are preferrable to fluorocarbon – such as where you need to cast further or need a line that will more easily cut through thick weed – but using some sort of fluoro leader is an advantage, such as IQ2 or the Kamo Kontour material which is specifically designed for this purpose where a heavy leader is needed in snaggy conditions.

A fluorocarbon leader will mean that the line close to your rig is almost invisible in water and is pinned down to the lake bed as well.

Just make sure that you use a knot that is fluorocarbon-friendly, such as back-to-back grinner knots, and that whatever lead system you choose is safe so that the fish can get rid of the lead or the hook link can detach from the leader – such as a Hybrid lead clip or a Heli-Safe system with the No Trace beads.